diff --git a/config/sql/se/Artworks.sql b/config/sql/se/Artworks.sql
index cb1991fd..45f8cdb2 100644
--- a/config/sql/se/Artworks.sql
+++ b/config/sql/se/Artworks.sql
@@ -7,7 +7,7 @@ CREATE TABLE IF NOT EXISTS `Artworks` (
   `CompletedYearIsCirca` boolean NOT NULL DEFAULT FALSE,
   `Created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `Updated` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-  `Status` enum('unverified', 'approved', 'declined', 'in_use') DEFAULT 'unverified',
+  `Status` enum('unverified', 'approved', 'declined', 'in_use') NOT NULL DEFAULT 'unverified',
   `SubmitterUserId` int(10) unsigned NULL,
   `ReviewerUserId` int(10) unsigned NULL,
   `MuseumUrl` varchar(255) NULL,
diff --git a/config/sql/se/EbookSources.sql b/config/sql/se/EbookSources.sql
index 46892730..4fd758b2 100644
--- a/config/sql/se/EbookSources.sql
+++ b/config/sql/se/EbookSources.sql
@@ -1,6 +1,6 @@
 CREATE TABLE IF NOT EXISTS `EbookSources` (
   `EbookId` int(10) unsigned NOT NULL,
-  `Type` enum('project_gutenberg', 'project_gutenberg_australia', 'project_gutenberg_canada', 'internet_archive', 'hathi_trust', 'wikisource', 'google_books', 'faded_page', 'other') DEFAULT 'other',
+  `Type` enum('project_gutenberg', 'project_gutenberg_australia', 'project_gutenberg_canada', 'internet_archive', 'hathi_trust', 'wikisource', 'google_books', 'faded_page', 'other') NOT NULL DEFAULT 'other',
   `Url` varchar(255) NOT NULL,
   `SortOrder` tinyint(3) unsigned NOT NULL,
   KEY `index1` (`EbookId`)
diff --git a/lib/Artist.php b/lib/Artist.php
index 67b9467b..ec849f97 100644
--- a/lib/Artist.php
+++ b/lib/Artist.php
@@ -9,49 +9,39 @@ use Safe\DateTimeImmutable;
  */
 class Artist{
 	use Traits\Accessor;
+	use Traits\PropertyFromHttp;
 
-	public ?int $ArtistId = null;
-	public ?string $Name = null;
-	public ?DateTimeImmutable $Created = null;
-	public ?DateTimeImmutable $Updated = null;
+	public int $ArtistId;
+	public string $Name = '';
+	public DateTimeImmutable $Created;
+	public DateTimeImmutable $Updated;
+	public ?int $DeathYear = null;
 
-	protected ?int $_DeathYear = null;
-	protected ?string $_UrlName = null;
-	protected ?string $_Url = null;
-	/** @var ?array<string> $_AlternateNames */
-	protected $_AlternateNames = null;
+	protected string $_UrlName;
+	protected string $_Url;
+	/** @var array<string> $_AlternateNames */
+	protected array $_AlternateNames;
 
-	// *******
-	// SETTERS
-	// *******
-
-	protected function SetDeathYear(?int $deathYear): void{
-		if($this->Name == 'Anonymous'){
-			$this->_DeathYear = null;
-		}
-		else {
-			$this->_DeathYear = $deathYear;
-		}
-	}
 
 	// *******
 	// GETTERS
 	// *******
 
 	protected function GetUrlName(): string{
-		if($this->Name === null || $this->Name == ''){
-			return '';
-		}
-
-		if($this->_UrlName === null){
-			$this->_UrlName = Formatter::MakeUrlSafe($this->Name);
+		if(!isset($this->_UrlName)){
+			if(!isset($this->Name) || $this->Name == ''){
+				$this->_UrlName = '';
+			}
+			else{
+				$this->_UrlName = Formatter::MakeUrlSafe($this->Name);
+			}
 		}
 
 		return $this->_UrlName;
 	}
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/artworks/' . $this->UrlName;
 		}
 
@@ -62,7 +52,7 @@ class Artist{
 	 * @return array<string>
 	 */
 	protected function GetAlternateNames(): array{
-		if($this->_AlternateNames === null){
+		if(!isset($this->_AlternateNames)){
 			$this->_AlternateNames = [];
 
 			$result = Db::Query('
@@ -79,6 +69,7 @@ class Artist{
 		return $this->_AlternateNames;
 	}
 
+
 	// *******
 	// METHODS
 	// *******
@@ -91,16 +82,15 @@ class Artist{
 
 		$error = new Exceptions\InvalidArtistException();
 
-		if($this->Name === null || $this->Name == ''){
+		if(!isset($this->Name) || $this->Name == ''){
 			$error->Add(new Exceptions\ArtistNameRequiredException());
 		}
-
-		if($this->Name !== null && strlen($this->Name) > ARTWORK_MAX_STRING_LENGTH){
+		elseif(strlen($this->Name) > ARTWORK_MAX_STRING_LENGTH){
 			$error->Add(new Exceptions\StringTooLongException('Artist Name'));
 		}
 
 		if($this->Name == 'Anonymous' && $this->DeathYear !== null){
-			$this->_DeathYear = null;
+			$this->DeathYear = null;
 		}
 
 		if($this->DeathYear !== null && ($this->DeathYear <= 0 || $this->DeathYear > $thisYear + 50)){
@@ -111,11 +101,16 @@ class Artist{
 			throw $error;
 		}
 	}
+
+	public function FillFromHttpPost(): void{
+		$this->PropertyFromHttp('Name');
+		$this->PropertyFromHttp('DeathYear');
+	}
+
 	// ***********
 	// ORM METHODS
 	// ***********
 
-
 	/**
 	 * @throws Exceptions\ArtistNotFoundException
 	 */
@@ -124,13 +119,11 @@ class Artist{
 			throw new Exceptions\ArtistNotFoundException();
 		}
 
-		$result = Db::Query('
+		return Db::Query('
 				SELECT *
 				from Artists
 				where ArtistId = ?
-			', [$artistId], Artist::class);
-
-		return $result[0] ?? throw new Exceptions\ArtistNotFoundException();
+			', [$artistId], Artist::class)[0] ?? throw new Exceptions\ArtistNotFoundException();
 	}
 
 	/**
@@ -141,15 +134,13 @@ class Artist{
 			throw new Exceptions\ArtistNotFoundException();
 		}
 
-		$result = Db::Query('
+		return Db::Query('
 				SELECT a.*
 					from Artists a
 					left outer join ArtistAlternateNames aan using (ArtistId)
 					where aan.UrlName = ?
 					limit 1
-			', [$urlName], Artist::class);
-
-		return $result[0] ?? throw new Exceptions\ArtistNotFoundException();
+			', [$urlName], Artist::class)[0] ?? throw new Exceptions\ArtistNotFoundException();
 	}
 
 	/**
diff --git a/lib/Artwork.php b/lib/Artwork.php
index ed4cffd8..a3e8ee9b 100644
--- a/lib/Artwork.php
+++ b/lib/Artwork.php
@@ -7,6 +7,7 @@ use function Safe\getimagesize;
 use function Safe\parse_url;
 use function Safe\preg_match;
 use function Safe\preg_replace;
+use function Safe\unlink;
 
 /**
  * @property string $UrlName
@@ -24,19 +25,20 @@ use function Safe\preg_replace;
  * @property string $Dimensions
  * @property Ebook $Ebook
  * @property Museum $Museum
- * @property User $Submitter
- * @property User $Reviewer
+ * @property ?User $Submitter
+ * @property ?User $Reviewer
  */
 class Artwork{
 	use Traits\Accessor;
+	use Traits\PropertyFromHttp;
 
-	public ?string $Name = null;
-	public ?int $ArtworkId = null;
-	public ?int $ArtistId = null;
+	public int $ArtworkId;
+	public string $Name = '';
+	public int $ArtistId;
 	public ?int $CompletedYear = null;
 	public bool $CompletedYearIsCirca = false;
-	public ?DateTimeImmutable $Created = null;
-	public ?DateTimeImmutable $Updated = null;
+	public DateTimeImmutable $Created;
+	public DateTimeImmutable $Updated;
 	public ?string $EbookUrl = null;
 	public ?int $SubmitterUserId = null;
 	public ?int $ReviewerUserId = null;
@@ -45,26 +47,27 @@ class Artwork{
 	public ?string $PublicationYearPageUrl = null;
 	public ?string $CopyrightPageUrl = null;
 	public ?string $ArtworkPageUrl = null;
-	public ?bool $IsPublishedInUs = null;
+	public bool $IsPublishedInUs = false;
 	public ?string $Exception = null;
 	public ?string $Notes = null;
-	public ?Enums\ImageMimeType $MimeType = null;
-	public ?Enums\ArtworkStatusType $Status = null;
+	public Enums\ImageMimeType $MimeType;
+	public Enums\ArtworkStatusType $Status = Enums\ArtworkStatusType::Unverified;
+
+	protected string $_UrlName;
+	protected string $_Url;
+	protected string $_EditUrl;
+	/** @var array<ArtworkTag> $_Tags */
+	protected array $_Tags;
+	protected Artist $_Artist;
+	protected string $_ImageUrl;
+	protected string $_ThumbUrl;
+	protected string $_Thumb2xUrl;
+	protected string $_Dimensions ;
+	protected ?Ebook $_Ebook;
+	protected ?Museum $_Museum;
+	protected ?User $_Submitter;
+	protected ?User $_Reviewer;
 
-	protected ?string $_UrlName = null;
-	protected ?string $_Url = null;
-	protected ?string $_EditUrl = null;
-	/** @var ?array<ArtworkTag> $_Tags */
-	protected $_Tags = null;
-	protected ?Artist $_Artist = null;
-	protected ?string $_ImageUrl = null;
-	protected ?string $_ThumbUrl = null;
-	protected ?string $_Thumb2xUrl = null;
-	protected ?string $_Dimensions = null;
-	protected ?Ebook $_Ebook = null;
-	protected ?Museum $_Museum = null;
-	protected ?User $_Submitter = null;
-	protected ?User $_Reviewer = null;
 
 	// *******
 	// SETTERS
@@ -74,45 +77,54 @@ class Artwork{
 	 * @param string|null|array<ArtworkTag> $tags
 	 */
 	protected function SetTags(null|string|array $tags): void{
-		if($tags === null || is_array($tags)){
+		if(is_array($tags)){
 			$this->_Tags = $tags;
 		}
-		elseif(is_string($tags)){
-			$tags = array_map('trim', explode(',', $tags));
-			$tags = array_values(array_filter($tags));
-			$tags = array_unique($tags);
+		else{
+			$tags = trim($tags ?? '');
 
-			$this->_Tags = array_map(function ($str){
-				$tag = new ArtworkTag();
-				$tag->Name = $str;
-				return $tag;
-			}, $tags);
+			if($tags === ''){
+				$this->_Tags = [];
+			}
+			else{
+				$tags = array_map('trim', explode(',', $tags));
+				$tags = array_values(array_filter($tags));
+				$tags = array_unique($tags);
+
+				$this->_Tags = array_map(function ($str): ArtworkTag{
+					$tag = new ArtworkTag();
+					$tag->Name = $str;
+					return $tag;
+				}, $tags);
+			}
 		}
 	}
 
+
 	// *******
 	// GETTERS
 	// *******
 
 	protected function GetUrlName(): string{
-		if($this->Name === null || $this->Name == ''){
-			return '';
-		}
-
-		if($this->_UrlName === null){
-			$this->_UrlName = Formatter::MakeUrlSafe($this->Name);
+		if(!isset($this->_UrlName)){
+			if(!isset($this->Name) || $this->Name == ''){
+				$this->_UrlName = '';
+			}
+			else{
+				$this->_UrlName = Formatter::MakeUrlSafe($this->Name);
+			}
 		}
 
 		return $this->_UrlName;
 	}
 
 	protected function GetSubmitter(): ?User{
-		if($this->_Submitter === null){
+		if(!isset($this->_Submitter)){
 			try{
 				$this->_Submitter = User::Get($this->SubmitterUserId);
 			}
 			catch(Exceptions\UserNotFoundException){
-				// Return null
+				$this->Submitter = null;
 			}
 		}
 
@@ -120,12 +132,12 @@ class Artwork{
 	}
 
 	protected function GetReviewer(): ?User{
-		if($this->_Reviewer === null){
+		if(!isset($this->_Reviewer)){
 			try{
 				$this->_Reviewer = User::Get($this->ReviewerUserId);
 			}
 			catch(Exceptions\UserNotFoundException){
-				// Return null
+				$this->_Reviewer = null;
 			}
 		}
 
@@ -133,7 +145,7 @@ class Artwork{
 	}
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/artworks/' . $this->Artist->UrlName . '/' . $this->UrlName;
 		}
 
@@ -141,7 +153,7 @@ class Artwork{
 	}
 
 	protected function GetEditUrl(): string{
-		if($this->_EditUrl === null){
+		if(!isset($this->_EditUrl)){
 			$this->_EditUrl = $this->Url . '/edit';
 		}
 
@@ -152,7 +164,7 @@ class Artwork{
 	 * @return array<ArtworkTag>
 	 */
 	protected function GetTags(): array{
-		if($this->_Tags === null){
+		if(!isset($this->_Tags)){
 			$this->_Tags = Db::Query('
 							SELECT t.*
 							from Tags t
@@ -168,34 +180,28 @@ class Artwork{
 	 * @throws Exceptions\InvalidUrlException
 	 */
 	public function GetMuseum(): ?Museum{
-		if($this->_Museum === null){
+		if(!isset($this->_Museum)){
 			try{
 				$this->_Museum = Museum::GetByUrl($this->MuseumUrl);
 			}
 			catch(Exceptions\MuseumNotFoundException){
-				// Pass
+				// Pass.
 			}
 		}
 
 		return $this->_Museum;
 	}
 
-	public function ImplodeTags(): string{
-		$tags = $this->Tags ?? [];
-		$tags = array_column($tags, 'Name');
-		return trim(implode(', ', $tags));
-	}
-
 	/**
 	 * @throws Exceptions\InvalidArtworkException
 	 */
 	protected function GetImageUrl(): string{
-		if($this->_ImageUrl === null){
-			if($this->ArtworkId === null || $this->MimeType === null){
+		if(!isset($this->_ImageUrl)){
+			if(!isset($this->ArtworkId) || !isset($this->MimeType)){
 				throw new Exceptions\InvalidArtworkException();
 			}
 
-			$this->_ImageUrl = COVER_ART_UPLOAD_PATH . $this->ArtworkId . $this->MimeType->GetFileExtension() . '?ts=' . $this->Updated?->getTimestamp();
+			$this->_ImageUrl = COVER_ART_UPLOAD_PATH . $this->ArtworkId . $this->MimeType->GetFileExtension() . '?ts=' . $this->Updated->getTimestamp();
 		}
 
 		return $this->_ImageUrl;
@@ -205,12 +211,12 @@ class Artwork{
 	 * @throws Exceptions\ArtworkNotFoundException
 	 */
 	protected function GetThumbUrl(): string{
-		if($this->_ThumbUrl === null){
-			if($this->ArtworkId === null){
+		if(!isset($this->_ThumbUrl)){
+			if(!isset($this->ArtworkId)){
 				throw new Exceptions\ArtworkNotFoundException();
 			}
 
-			$this->_ThumbUrl = COVER_ART_UPLOAD_PATH . $this->ArtworkId . '-thumb.jpg' . '?ts=' . $this->Updated?->getTimestamp();
+			$this->_ThumbUrl = COVER_ART_UPLOAD_PATH . $this->ArtworkId . '-thumb.jpg' . '?ts=' . $this->Updated->getTimestamp();
 		}
 
 		return $this->_ThumbUrl;
@@ -220,12 +226,12 @@ class Artwork{
 	 * @throws Exceptions\ArtworkNotFoundException
 	 */
 	protected function GetThumb2xUrl(): string{
-		if($this->_Thumb2xUrl === null){
-			if($this->ArtworkId === null){
+		if(!isset($this->_Thumb2xUrl)){
+			if(!isset($this->ArtworkId)){
 				throw new Exceptions\ArtworkNotFoundException();
 			}
 
-			$this->_Thumb2xUrl = COVER_ART_UPLOAD_PATH . $this->ArtworkId . '-thumb@2x.jpg' . '?ts=' . $this->Updated?->getTimestamp();
+			$this->_Thumb2xUrl = COVER_ART_UPLOAD_PATH . $this->ArtworkId . '-thumb@2x.jpg' . '?ts=' . $this->Updated->getTimestamp();
 		}
 
 		return $this->_Thumb2xUrl;
@@ -244,22 +250,24 @@ class Artwork{
 	}
 
 	protected function GetDimensions(): string{
-		$this->_Dimensions = '';
-		try{
-			list($imageWidth, $imageHeight) = getimagesize($this->ImageFsPath);
-			if($imageWidth && $imageHeight){
-				$this->_Dimensions = number_format($imageWidth) . ' × ' . number_format($imageHeight);
+		if(!isset($this->Dimensions)){
+			$this->_Dimensions = '';
+			try{
+				list($imageWidth, $imageHeight) = getimagesize($this->ImageFsPath);
+				if($imageWidth && $imageHeight){
+					$this->_Dimensions = number_format($imageWidth) . ' × ' . number_format($imageHeight);
+				}
+			}
+			catch(Exception){
+				// Image doesn't exist, return a blank string.
 			}
-		}
-		catch(Exception){
-			// Image doesn't exist, return blank string
 		}
 
 		return $this->_Dimensions;
 	}
 
 	protected function GetEbook(): ?Ebook{
-		if($this->_Ebook === null){
+		if(!isset($this->_Ebook)){
 			if($this->EbookUrl === null){
 				return null;
 			}
@@ -277,9 +285,11 @@ class Artwork{
 		return $this->_Ebook;
 	}
 
+
 	// *******
 	// METHODS
 	// *******
+
 	public function CanBeEditedBy(?User $user): bool{
 		if($user === null){
 			return false;
@@ -336,15 +346,16 @@ class Artwork{
 		$thisYear = intval(NOW->format('Y'));
 		$error = new Exceptions\InvalidArtworkException();
 
-		if($this->Artist === null){
+		if(!isset($this->Artist)){
 			$error->Add(new Exceptions\InvalidArtistException());
 		}
-
-		try{
-			$this->Artist->Validate();
-		}
-		catch(Exceptions\ValidationException $ex){
-			$error->Add($ex);
+		else{
+			try{
+				$this->Artist->Validate();
+			}
+			catch(Exceptions\ValidationException $ex){
+				$error->Add($ex);
+			}
 		}
 
 		if($this->Exception !== null && trim($this->Exception) == ''){
@@ -355,12 +366,17 @@ class Artwork{
 			$this->Notes = null;
 		}
 
-		if($this->Name === null || $this->Name == ''){
-			$error->Add(new Exceptions\ArtworkNameRequiredException());
-		}
+		if(isset($this->Name)){
+			if($this->Name == ''){
+				$error->Add(new Exceptions\ArtworkNameRequiredException());
+			}
 
-		if($this->Name !== null && strlen($this->Name) > ARTWORK_MAX_STRING_LENGTH){
-			$error->Add(new Exceptions\StringTooLongException('Artwork Name'));
+			if(strlen($this->Name) > ARTWORK_MAX_STRING_LENGTH){
+				$error->Add(new Exceptions\StringTooLongException('Artwork Name'));
+			}
+		}
+		else{
+			$error->Add(new Exceptions\ArtworkNameRequiredException());
 		}
 
 		if($this->CompletedYear !== null && ($this->CompletedYear <= 0 || $this->CompletedYear > $thisYear)){
@@ -375,27 +391,32 @@ class Artwork{
 			$error->Add(new Exceptions\InvalidPublicationYearException());
 		}
 
-		if($this->Status === null){
+		if(!isset($this->Status)){
 			$error->Add(new Exceptions\InvalidArtworkException('Invalid status.'));
 		}
 
-		if(count($this->Tags) == 0){
+		if(isset($this->Tags)){
+			if(count($this->Tags) == 0){
+				$error->Add(new Exceptions\TagsRequiredException());
+			}
+
+			if(count($this->Tags) > ARTWORK_MAX_TAGS){
+				$error->Add(new Exceptions\TooManyTagsException());
+			}
+
+			foreach($this->Tags as $tag){
+				try{
+					$tag->Validate();
+				}
+				catch(Exceptions\ValidationException $ex){
+					$error->Add($ex);
+				}
+			}
+		}
+		else{
 			$error->Add(new Exceptions\TagsRequiredException());
 		}
 
-		if(count($this->Tags) > ARTWORK_MAX_TAGS){
-			$error->Add(new Exceptions\TooManyTagsException());
-		}
-
-		foreach($this->Tags as $tag){
-			try{
-				$tag->Validate();
-			}
-			catch(Exceptions\ValidationException $ex){
-				$error->Add($ex);
-			}
-		}
-
 		if($this->MuseumUrl !== null){
 			if(strlen($this->MuseumUrl) > ARTWORK_MAX_STRING_LENGTH){
 				$error->Add(new Exceptions\StringTooLongException('Link to an approved museum page'));
@@ -482,36 +503,38 @@ class Artwork{
 			}
 		}
 
-		// Check for existing Artwork objects with the same URL but different Artwork IDs.
-		try{
-			$existingArtwork = Artwork::GetByUrl($this->Artist->UrlName, $this->UrlName);
-			if($existingArtwork->ArtworkId != $this->ArtworkId){
-				// Duplicate found, alert the user
-				$error->Add(new Exceptions\ArtworkAlreadyExistsException());
+		// Check for existing `Artwork` objects with the same URL but different `ArtworkID`s.
+		if(isset($this->ArtworkId)){
+			try{
+				$existingArtwork = Artwork::GetByUrl($this->Artist->UrlName, $this->UrlName);
+				if($existingArtwork->ArtworkId != $this->ArtworkId){
+					// Duplicate found, alert the user.
+					$error->Add(new Exceptions\ArtworkAlreadyExistsException());
+				}
 			}
-		}
-		catch(Exceptions\ArtworkNotFoundException){
-			// No duplicates found, continue
-		}
-
-		if($isImageRequired && $imagePath === null){
-			$error->Add(new Exceptions\InvalidImageUploadException('An image is required.'));
-		}
-
-		if($imagePath !== null && $this->MimeType !== null){
-			if(!is_writable(WEB_ROOT . COVER_ART_UPLOAD_PATH)){
-				$error->Add(new Exceptions\InvalidImageUploadException('Upload path not writable.'));
-			}
-
-			// Check for minimum dimensions
-			list($imageWidth, $imageHeight) = getimagesize($imagePath);
-			if(!$imageWidth || !$imageHeight || $imageWidth < ARTWORK_IMAGE_MINIMUM_WIDTH || $imageHeight < ARTWORK_IMAGE_MINIMUM_HEIGHT){
-				$error->Add(new Exceptions\ArtworkImageDimensionsTooSmallException());
+			catch(Exceptions\ArtworkNotFoundException){
+				// No duplicates found, continue.
 			}
 		}
 
-		if($imagePath !== null && $this->MimeType === null && !$error->Has('Exceptions\InvalidImageUploadException')){
-			// Only notify of wrong mimetype if there are no other problem with the uploaded image
+		if($isImageRequired){
+			if($imagePath === null){
+				$error->Add(new Exceptions\InvalidImageUploadException('An image is required.'));
+			}
+			else{
+				if(!is_writable(WEB_ROOT . COVER_ART_UPLOAD_PATH)){
+					$error->Add(new Exceptions\InvalidImageUploadException('Upload path not writable.'));
+				}
+
+				// Check for minimum dimensions.
+				list($imageWidth, $imageHeight) = getimagesize($imagePath);
+				if(!$imageWidth || !$imageHeight || $imageWidth < ARTWORK_IMAGE_MINIMUM_WIDTH || $imageHeight < ARTWORK_IMAGE_MINIMUM_HEIGHT){
+					$error->Add(new Exceptions\ArtworkImageDimensionsTooSmallException());
+				}
+			}
+		}
+
+		if(!isset($this->MimeType)){
 			$error->Add(new Exceptions\InvalidMimeTypeException());
 		}
 
@@ -520,6 +543,12 @@ class Artwork{
 		}
 	}
 
+	public function ImplodeTags(): string{
+		$tags = $this->Tags ?? [];
+		$tags = array_column($tags, 'Name');
+		return trim(implode(', ', $tags));
+	}
+
 	/**
 	 * @throws Exceptions\InvalidUrlException
 	 * @throws Exceptions\InvalidPageScanUrlException
@@ -661,11 +690,12 @@ class Artwork{
 	 * @throws Exceptions\InvalidImageUploadException
 	 */
 	public function Create(?string $imagePath = null): void{
-		$this->MimeType = Enums\ImageMimeType::FromFile($imagePath);
+		$this->MimeType = Enums\ImageMimeType::FromFile($imagePath) ?? throw new Exceptions\InvalidImageUploadException();
 
 		$this->Validate($imagePath, true);
 
 		$this->Created = NOW;
+		$this->Updated = NOW;
 
 		$tags = [];
 		foreach($this->Tags as $artworkTag){
@@ -677,7 +707,7 @@ class Artwork{
 
 		Db::Query('
 			INSERT into
-			Artworks (ArtistId, Name, UrlName, CompletedYear, CompletedYearIsCirca, Created, Status, SubmitterUserId, ReviewerUserId, MuseumUrl,
+			Artworks (ArtistId, Name, UrlName, CompletedYear, CompletedYearIsCirca, Created, Updated, Status, SubmitterUserId, ReviewerUserId, MuseumUrl,
 			                      PublicationYear, PublicationYearPageUrl, CopyrightPageUrl, ArtworkPageUrl, IsPublishedInUs,
 			                      EbookUrl, MimeType, Exception, Notes)
 			values (?,
@@ -698,9 +728,10 @@ class Artwork{
 			        ?,
 			        ?,
 			        ?,
+			        ?,
 			        ?)
 		', [$this->Artist->ArtistId, $this->Name, $this->UrlName, $this->CompletedYear, $this->CompletedYearIsCirca,
-				$this->Created, $this->Status, $this->SubmitterUserId, $this->ReviewerUserId, $this->MuseumUrl, $this->PublicationYear, $this->PublicationYearPageUrl,
+				$this->Created, $this->Updated, $this->Status, $this->SubmitterUserId, $this->ReviewerUserId, $this->MuseumUrl, $this->PublicationYear, $this->PublicationYearPageUrl,
 				$this->CopyrightPageUrl, $this->ArtworkPageUrl, $this->IsPublishedInUs, $this->EbookUrl, $this->MimeType, $this->Exception, $this->Notes]
 		);
 
@@ -726,16 +757,16 @@ class Artwork{
 	 * @throws Exceptions\InvalidImageUploadException
 	 */
 	public function Save(?string $imagePath = null): void{
-		$this->_UrlName = null;
+		unset($this->_UrlName);
 
 		if($imagePath !== null){
-			$this->MimeType = Enums\ImageMimeType::FromFile($imagePath);
+			$this->MimeType = Enums\ImageMimeType::FromFile($imagePath) ?? throw new Exceptions\InvalidImageUploadException();
 
 			// Manually set the updated timestamp, because if we only update the image and nothing else, the row's updated timestamp won't change automatically.
 			$this->Updated = NOW;
-			$this->_ImageUrl = null;
-			$this->_ThumbUrl = null;
-			$this->_Thumb2xUrl = null;
+			unset($this->_ImageUrl);
+			unset($this->_ThumbUrl);
+			unset($this->_Thumb2xUrl);
 		}
 
 		$this->Validate($imagePath, false);
@@ -828,8 +859,30 @@ class Artwork{
 			from Artworks
 			where ArtworkId = ?
 		', [$this->ArtworkId]);
+
+		try{
+			unlink($this->ImageFsPath);
+		}
+		catch(\Safe\Exceptions\FilesystemException){
+			// Pass.
+		}
+
+		try{
+			unlink($this->ThumbFsPath);
+		}
+		catch(\Safe\Exceptions\FilesystemException){
+			// Pass.
+		}
+
+		try{
+			unlink($this->Thumb2xFsPath);
+		}
+		catch(\Safe\Exceptions\FilesystemException){
+			// Pass.
+		}
 	}
 
+
 	// ***********
 	// ORM METHODS
 	// ***********
@@ -871,14 +924,10 @@ class Artwork{
 
 	public static function FromHttpPost(): Artwork{
 		$artwork = new Artwork();
-		$artwork->Artist = new Artist();
 
-		$artwork->Artist->Name = HttpInput::Str(POST, 'artist-name');
-		$artwork->Artist->DeathYear = HttpInput::Int(POST, 'artist-year-of-death');
-
-		$artwork->Name = HttpInput::Str(POST, 'artwork-name');
+		$artwork->Name = HttpInput::Str(POST, 'artwork-name') ?? '';
 		$artwork->CompletedYear = HttpInput::Int(POST, 'artwork-year');
-		$artwork->CompletedYearIsCirca = HttpInput::Bool(POST, 'artwork-year-is-circa') ?? false;
+		$artwork->CompletedYearIsCirca = HttpInput::Bool(POST, 'artwork-completed-year-is-circa') ?? false;
 		$artwork->Tags = HttpInput::Str(POST, 'artwork-tags') ?? [];
 		$artwork->Status = Enums\ArtworkStatusType::tryFrom(HttpInput::Str(POST, 'artwork-status') ?? '') ?? Enums\ArtworkStatusType::Unverified;
 		$artwork->EbookUrl = HttpInput::Str(POST, 'artwork-ebook-url');
@@ -893,4 +942,28 @@ class Artwork{
 
 		return $artwork;
 	}
+
+	public function FillFromHttpPost(): void{
+		if(!isset($this->Artist)){
+			$this->Artist = new Artist();
+		}
+
+		$this->Artist->FillFromHttpPost();
+
+		$this->PropertyFromHttp('Name');
+		$this->PropertyFromHttp('CompletedYear');
+		$this->PropertyFromHttp('CompletedYearIsCirca');
+		$this->PropertyFromHttp('Status');
+		$this->PropertyFromHttp('EbookUrl');
+		$this->PropertyFromHttp('IsPublishedInUs');
+		$this->PropertyFromHttp('PublicationYear');
+		$this->PropertyFromHttp('PublicationYearPageUrl');
+		$this->PropertyFromHttp('CopyrightPageUrl');
+		$this->PropertyFromHttp('ArtworkPageUrl');
+		$this->PropertyFromHttp('MuseumUrl');
+		$this->PropertyFromHttp('Exception');
+		$this->PropertyFromHttp('Notes');
+
+		$this->Tags = HttpInput::Str(POST, 'artwork-tags') ?? ''; // Converted from a string to an array via a setter.
+	}
 }
diff --git a/lib/ArtworkTag.php b/lib/ArtworkTag.php
index e3313bb6..0e3ae556 100644
--- a/lib/ArtworkTag.php
+++ b/lib/ArtworkTag.php
@@ -7,18 +7,20 @@ class ArtworkTag extends Tag{
 		$this->Type = Enums\TagType::Artwork;
 	}
 
+
 	// *******
 	// GETTERS
 	// *******
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/artworks?query=' . Formatter::MakeUrlSafe($this->Name);
 		}
 
 		return $this->_Url;
 	}
 
+
 	// *******
 	// METHODS
 	// *******
@@ -29,20 +31,27 @@ class ArtworkTag extends Tag{
 	public function Validate(): void{
 		$error = new Exceptions\InvalidArtworkTagException($this->Name);
 
-		$this->Name = mb_strtolower(trim($this->Name));
-		// Collapse spaces into one
-		$this->Name = preg_replace('/[\s]+/ius', ' ', $this->Name);
+		if(isset($this->Name)){
+			$this->Name = mb_strtolower(trim($this->Name));
+			// Collapse spaces into one
+			$this->Name = preg_replace('/[\s]+/ius', ' ', $this->Name);
 
-		if(strlen($this->Name) == 0){
-			$error->Add(new Exceptions\InvalidArtworkTagNameException());
+			if(strlen($this->Name) == 0){
+				$error->Add(new Exceptions\InvalidArtworkTagNameException());
+			}
+
+			if(strlen($this->Name) > ARTWORK_MAX_STRING_LENGTH){
+				$error->Add(new Exceptions\StringTooLongException('Artwork tag: '. $this->Name));
+			}
+
+			if(preg_match('/[^\sa-z0-9]/ius', $this->Name)){
+				$error->Add(new Exceptions\InvalidArtworkTagNameException());
+			}
+
+			$this->UrlName = Formatter::MakeUrlSafe($this->Name);
 		}
-
-		if(strlen($this->Name) > ARTWORK_MAX_STRING_LENGTH){
-			$error->Add(new Exceptions\StringTooLongException('Artwork tag: '. $this->Name));
-		}
-
-		if(preg_match('/[^\sa-z0-9]/ius', $this->Name)){
-			$error->Add(new Exceptions\InvalidArtworkTagNameException());
+		else{
+			$error->Add(new Exceptions\ArtworkTagNameRequiredException());
 		}
 
 		if($this->Type != Enums\TagType::Artwork){
@@ -61,10 +70,11 @@ class ArtworkTag extends Tag{
 		$this->Validate();
 
 		Db::Query('
-			INSERT into Tags (Name, Type)
+			INSERT into Tags (Name, UrlName, Type)
 			values (?,
+				?,
 				?)
-		', [$this->Name, $this->Type]);
+		', [$this->Name, $this->UrlName, $this->Type]);
 		$this->TagId = Db::GetLastInsertedId();
 	}
 
diff --git a/lib/AtomFeed.php b/lib/AtomFeed.php
index f3aa0887..1b2a8e02 100644
--- a/lib/AtomFeed.php
+++ b/lib/AtomFeed.php
@@ -19,18 +19,19 @@ class AtomFeed extends Feed{
 		$this->Stylesheet = SITE_URL . '/feeds/atom/style';
 	}
 
+
 	// *******
 	// METHODS
 	// *******
 
 	protected function GetXmlString(): string{
-		if($this->XmlString === null){
+		if(!isset($this->_XmlString)){
 			$feed = Template::AtomFeed(['id' => $this->Id, 'url' => $this->Url, 'title' => $this->Title, 'subtitle' => $this->Subtitle, 'updated' => $this->Updated, 'entries' => $this->Entries]);
 
-			$this->XmlString = $this->CleanXmlString($feed);
+			$this->_XmlString = $this->CleanXmlString($feed);
 		}
 
-		return $this->XmlString;
+		return $this->_XmlString;
 	}
 
 	public function SaveIfChanged(): bool{
@@ -58,7 +59,7 @@ class AtomFeed extends Feed{
 				$obj->Id = SITE_URL . $entry->Url;
 			}
 			else{
-				$obj->Updated = $entry->Updated !== null ? $entry->Updated->format(Enums\DateTimeFormat::Iso->value) : '';
+				$obj->Updated = $entry->Updated->format(Enums\DateTimeFormat::Iso->value);
 				$obj->Id = $entry->Id;
 			}
 			$currentEntries[] = $obj;
diff --git a/lib/Collection.php b/lib/Collection.php
index bb6af2a2..faf8bfbe 100644
--- a/lib/Collection.php
+++ b/lib/Collection.php
@@ -13,6 +13,11 @@ class Collection{
 	public ?Enums\CollectionType $Type = null;
 	protected ?string $_Url = null;
 
+
+	// *******
+	// GETTERS
+	// *******
+
 	protected function GetUrl(): string{
 		if($this->_Url === null){
 			$this->_Url = '/collections/' . $this->UrlName;
@@ -21,6 +26,11 @@ class Collection{
 		return $this->_Url;
 	}
 
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
 	public static function FromName(string $name): Collection{
 		$instance = new Collection();
 		$instance->Name = $name;
@@ -45,6 +55,11 @@ class Collection{
 		return $result[0] ?? throw new Exceptions\CollectionNotFoundException();;
 	}
 
+
+	// *******
+	// METHODS
+	// *******
+
 	public function GetSortedName(): string{
 		return preg_replace('/^(the|and|a|)\s/ius', '', $this->Name);
 	}
diff --git a/lib/CollectionMembership.php b/lib/CollectionMembership.php
index 8df0b276..d13bb00c 100644
--- a/lib/CollectionMembership.php
+++ b/lib/CollectionMembership.php
@@ -5,9 +5,10 @@
 class CollectionMembership{
 	use Traits\Accessor;
 
-	public ?int $EbookId = null;
-	public ?int $CollectionId = null;
+	public int $EbookId;
+	public int $CollectionId;
 	public ?int $SequenceNumber = null;
-	public ?int $SortOrder = null;
-	protected ?Collection $_Collection = null;
+	public int $SortOrder;
+
+	protected Collection $_Collection;
 }
diff --git a/lib/Contributor.php b/lib/Contributor.php
index f02a72e9..1f69b20f 100644
--- a/lib/Contributor.php
+++ b/lib/Contributor.php
@@ -1,11 +1,8 @@
 <?
-
-use Safe\DateTimeImmutable;
-
 use function Safe\preg_match;
 
 class Contributor{
-	public ?int $EbookId = null;
+	public int $EbookId;
 	public string $Name;
 	public string $UrlName;
 	public ?string $SortName = null;
@@ -13,19 +10,11 @@ class Contributor{
 	public ?string $MarcRole = null;
 	public ?string $FullName = null;
 	public ?string $NacoafUrl = null;
-	public ?int $SortOrder = null;
+	public int $SortOrder;
 
-	public static function FromProperties(string $name, string $sortName = null, string $fullName = null, string $wikipediaUrl = null, string $marcRole = null, string $nacoafUrl = null): Contributor{
-		$instance = new Contributor();
-		$instance->Name = str_replace('\'', '’', $name);
-		$instance->UrlName = Formatter::MakeUrlSafe($name);
-		$instance->SortName = $sortName;
-		$instance->FullName = $fullName;
-		$instance->WikipediaUrl = $wikipediaUrl;
-		$instance->MarcRole = $marcRole;
-		$instance->NacoafUrl = $nacoafUrl;
-		return $instance;
-	}
+	// *******
+	// METHODS
+	// *******
 
 	/**
 	 * @throws Exceptions\ValidationException
diff --git a/lib/DonationDrive.php b/lib/DonationDrive.php
index 0840a6b0..9e689b3b 100644
--- a/lib/DonationDrive.php
+++ b/lib/DonationDrive.php
@@ -18,15 +18,10 @@ class DonationDrive{
 	public function __construct(public string $Name, public DateTimeImmutable $Start, public DateTimeImmutable $End, public int $BaseTargetDonationCount, public int $StretchTargetDonationCount){
 	}
 
-	public static function GetByIsRunning(): ?DonationDrive{
-		foreach(DONATION_DRIVE_DATES as $donationDrive){
-			if(NOW > $donationDrive->Start && NOW < $donationDrive->End){
-				return $donationDrive;
-			}
-		}
 
-		return null;
-	}
+	// *******
+	// GETTERS
+	// *******
 
 	protected function GetDonationCount(): int{
 		if(!isset($this->_DonationCount)){
@@ -92,4 +87,19 @@ class DonationDrive{
 
 		return $this->_IsStretchEnabled;
 	}
+
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
+	public static function GetByIsRunning(): ?DonationDrive{
+		foreach(DONATION_DRIVE_DATES as $donationDrive){
+			if(NOW > $donationDrive->Start && NOW < $donationDrive->End){
+				return $donationDrive;
+			}
+		}
+
+		return null;
+	}
 }
diff --git a/lib/Ebook.php b/lib/Ebook.php
index e4c77a8f..46105bf1 100644
--- a/lib/Ebook.php
+++ b/lib/Ebook.php
@@ -46,7 +46,7 @@ use function Safe\shell_exec;
 class Ebook{
 	use Traits\Accessor;
 
-	public ?int $EbookId = null;
+	public int $EbookId;
 	public string $Identifier;
 	public string $WwwFilesystemPath;
 	public string $RepoFilesystemPath;
@@ -56,12 +56,12 @@ class Ebook{
 	public ?string $KepubUrl = null;
 	public ?string $Azw3Url = null;
 	public ?string $DistCoverUrl = null;
-	public ?string $Title = null;
+	public string $Title;
 	public ?string $FullTitle = null;
 	public ?string $AlternateTitle = null;
-	public ?string $Description = null;
-	public ?string $LongDescription = null;
-	public ?string $Language = null;
+	public string $Description;
+	public string $LongDescription;
+	public string $Language;
 	public int $WordCount;
 	public float $ReadingEase;
 	public ?string $GitHubUrl = null;
@@ -71,47 +71,48 @@ class Ebook{
 	public DateTimeImmutable $Created;
 	public DateTimeImmutable $Updated;
 	public ?int $TextSinglePageByteCount = null;
+
 	/** @var array<GitCommit> $_GitCommits */
-	protected $_GitCommits = null;
+	protected array $_GitCommits;
 	/** @var array<EbookTag> $_Tags */
-	protected $_Tags = null;
+	protected array $_Tags;
 	/** @var array<LocSubject> $_LocSubjects */
-	protected $_LocSubjects = null;
+	protected array $_LocSubjects;
 	/** @var array<CollectionMembership> $_CollectionMemberships */
-	protected $_CollectionMemberships = null;
+	protected array $_CollectionMemberships;
 	/** @var array<EbookSource> $_Sources */
-	protected $_Sources = null;
+	protected array $_Sources;
 	/** @var array<Contributor> $_Authors */
-	protected $_Authors = null;
+	protected array $_Authors;
 	/** @var array<Contributor> $_Illustrators */
-	protected $_Illustrators = null;
+	protected array $_Illustrators;
 	/** @var array<Contributor> $_Translators */
-	protected $_Translators = null;
+	protected array$_Translators;
 	/** @var array<Contributor> $_Contributors */
-	protected $_Contributors = null;
+	protected array $_Contributors;
 	/** @var ?array<string> $_TocEntries */
-	protected $_TocEntries = null; // A list of non-Roman ToC entries ONLY IF the work has the 'se:is-a-collection' metadata element, null otherwise.
-	protected ?string $_Url = null;
-	protected ?bool $_HasDownloads = null;
-	protected ?string $_UrlSafeIdentifier = null;
-	protected ?string $_HeroImageUrl = null;
-	protected ?string $_HeroImageAvifUrl = null;
-	protected ?string $_HeroImage2xUrl = null;
-	protected ?string $_HeroImage2xAvifUrl = null;
-	protected ?string $_CoverImageUrl = null;
-	protected ?string $_CoverImageAvifUrl = null;
-	protected ?string $_CoverImage2xUrl = null;
-	protected ?string $_CoverImage2xAvifUrl = null;
-	protected ?string $_ReadingEaseDescription = null;
-	protected ?string $_ReadingTime = null;
-	protected ?string $_AuthorsHtml = null;
-	protected ?string $_AuthorsUrl = null; // This is a single URL even if there are multiple authors; for example, /ebooks/karl-marx_friedrich-engels/
-	protected ?string $_ContributorsHtml = null;
-	protected ?string $_TitleWithCreditsHtml = null;
-	protected ?string $_TextUrl = null;
-	protected ?string $_TextSinglePageUrl = null;
-	protected ?string $_TextSinglePageSizeFormatted = null;
-	protected ?string $_IndexableText = null;
+	protected ?array $_TocEntries = null; // A list of non-Roman ToC entries *only if* the work has the `se:is-a-collection` metadata element; `null` otherwise.
+	protected string $_Url;
+	protected bool $_HasDownloads;
+	protected string $_UrlSafeIdentifier;
+	protected string $_HeroImageUrl;
+	protected string $_HeroImageAvifUrl;
+	protected string $_HeroImage2xUrl;
+	protected string $_HeroImage2xAvifUrl;
+	protected string $_CoverImageUrl;
+	protected string $_CoverImageAvifUrl;
+	protected string $_CoverImage2xUrl;
+	protected string $_CoverImage2xAvifUrl;
+	protected string $_ReadingEaseDescription;
+	protected string $_ReadingTime;
+	protected string $_AuthorsHtml;
+	protected string $_AuthorsUrl; // This is a single URL even if there are multiple authors; for example, `/ebooks/karl-marx_friedrich-engels/`.
+	protected string $_ContributorsHtml;
+	protected string $_TitleWithCreditsHtml;
+	protected string $_TextUrl;
+	protected string $_TextSinglePageUrl;
+	protected string $_TextSinglePageSizeFormatted;
+	protected string $_IndexableText;
 
 	// *******
 	// GETTERS
@@ -121,7 +122,7 @@ class Ebook{
 	 * @return array<GitCommit>
 	 */
 	protected function GetGitCommits(): array{
-		if($this->_GitCommits === null){
+		if(!isset($this->_GitCommits)){
 			$this->_GitCommits = Db::Query('
 							SELECT *
 							from GitCommits
@@ -137,7 +138,7 @@ class Ebook{
 	 * @return array<EbookTag>
 	 */
 	protected function GetTags(): array{
-		if($this->_Tags === null){
+		if(!isset($this->_Tags)){
 			$this->_Tags = Db::Query('
 						SELECT t.*
 						from Tags t
@@ -154,7 +155,7 @@ class Ebook{
 	 * @return array<LocSubject>
 	 */
 	protected function GetLocSubjects(): array{
-		if($this->_LocSubjects === null){
+		if(!isset($this->_LocSubjects)){
 			$this->_LocSubjects = Db::Query('
 							SELECT l.*
 							from LocSubjects l
@@ -171,7 +172,7 @@ class Ebook{
 	 * @return array<CollectionMembership>
 	 */
 	protected function GetCollectionMemberships(): array{
-		if($this->_CollectionMemberships === null){
+		if(!isset($this->_CollectionMemberships)){
 			$this->_CollectionMemberships = Db::Query('
 							SELECT *
 							from CollectionEbooks
@@ -187,7 +188,7 @@ class Ebook{
 	 * @return array<EbookSource>
 	 */
 	protected function GetSources(): array{
-		if($this->_Sources === null){
+		if(!isset($this->_Sources)){
 			$this->_Sources = Db::Query('
 						SELECT *
 						from EbookSources
@@ -203,7 +204,7 @@ class Ebook{
 	 * @return array<Contributor>
 	 */
 	protected function GetAuthors(): array{
-		if($this->_Authors === null){
+		if(!isset($this->_Authors)){
 			$this->_Authors = Db::Query('
 						SELECT *
 						from Contributors
@@ -220,7 +221,7 @@ class Ebook{
 	 * @return array<Contributor>
 	 */
 	protected function GetIllustrators(): array{
-		if($this->_Illustrators === null){
+		if(!isset($this->_Illustrators)){
 			$this->_Illustrators = Db::Query('
 							SELECT *
 							from Contributors
@@ -237,7 +238,7 @@ class Ebook{
 	 * @return array<Contributor>
 	 */
 	protected function GetTranslators(): array{
-		if($this->_Translators === null){
+		if(!isset($this->_Translators)){
 			$this->_Translators = Db::Query('
 							SELECT *
 							from Contributors
@@ -254,7 +255,7 @@ class Ebook{
 	 * @return array<Contributor>
 	 */
 	protected function GetContributors(): array{
-		if($this->_Contributors === null){
+		if(!isset($this->_Contributors)){
 			$this->_Contributors = Db::Query('
 							SELECT *
 							from Contributors
@@ -268,10 +269,10 @@ class Ebook{
 	}
 
 	/**
-	 * @return array<string>
+	 * @return ?array<string>
 	 */
-	protected function GetTocEntries(): array{
-		if($this->_TocEntries === null){
+	protected function GetTocEntries(): ?array{
+		if(!isset($this->_TocEntries)){
 			$this->_TocEntries = [];
 
 			$result = Db::Query('
@@ -279,18 +280,22 @@ class Ebook{
 					from TocEntries
 					where EbookId = ?
 					order by SortOrder asc
-				', [$this->EbookId], stdClass::class);
+				', [$this->EbookId]);
 
 			foreach($result as $row){
 				$this->_TocEntries[] = $row->TocEntry;
 			}
+
+			if(sizeof($this->_TocEntries) == 0){
+				$this->_TocEntries = null;
+			}
 		}
 
 		return $this->_TocEntries;
 	}
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = str_replace(WEB_ROOT, '', $this->WwwFilesystemPath);
 		}
 
@@ -298,7 +303,7 @@ class Ebook{
 	}
 
 	protected function GetHasDownloads(): bool{
-		if($this->_HasDownloads === null){
+		if(!isset($this->_HasDownloads)){
 			$this->_HasDownloads = $this->EpubUrl || $this->AdvancedEpubUrl || $this->KepubUrl || $this->Azw3Url;
 		}
 
@@ -306,7 +311,7 @@ class Ebook{
 	}
 
 	protected function GetUrlSafeIdentifier(): string{
-		if($this->_UrlSafeIdentifier === null){
+		if(!isset($this->_UrlSafeIdentifier)){
 			$this->_UrlSafeIdentifier = str_replace(['url:https://standardebooks.org/ebooks/', '/'], ['', '_'], $this->Identifier);
 		}
 
@@ -318,7 +323,7 @@ class Ebook{
 	}
 
 	protected function GetHeroImageUrl(): string{
-		if($this->_HeroImageUrl === null){
+		if(!isset($this->_HeroImageUrl)){
 			$this->_HeroImageUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-hero.jpg';
 		}
 
@@ -326,7 +331,7 @@ class Ebook{
 	}
 
 	protected function GetHeroImageAvifUrl(): ?string{
-		if($this->_HeroImageAvifUrl === null){
+		if(!isset($this->_HeroImageAvifUrl)){
 			if(file_exists(WEB_ROOT . '/images/covers/' . $this->UrlSafeIdentifier . '-hero.avif')){
 				$this->_HeroImageAvifUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-hero.avif';
 			}
@@ -336,7 +341,7 @@ class Ebook{
 	}
 
 	protected function GetHeroImage2xUrl(): string{
-		if($this->_HeroImage2xUrl === null){
+		if(!isset($this->_HeroImage2xUrl)){
 			$this->_HeroImage2xUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-hero@2x.jpg';
 		}
 
@@ -344,7 +349,7 @@ class Ebook{
 	}
 
 	protected function GetHeroImage2xAvifUrl(): ?string{
-		if($this->_HeroImage2xAvifUrl === null){
+		if(!isset($this->_HeroImage2xAvifUrl)){
 			if(file_exists(WEB_ROOT . '/images/covers/' . $this->UrlSafeIdentifier . '-hero@2x.avif')){
 				$this->_HeroImage2xAvifUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-hero@2x.avif';
 			}
@@ -354,7 +359,7 @@ class Ebook{
 	}
 
 	protected function GetCoverImageUrl(): string{
-		if($this->_CoverImageUrl === null){
+		if(!isset($this->_CoverImageUrl)){
 			$this->_CoverImageUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-cover.jpg';
 		}
 
@@ -362,7 +367,7 @@ class Ebook{
 	}
 
 	protected function GetCoverImageAvifUrl(): ?string{
-		if($this->_CoverImageAvifUrl === null){
+		if(!isset($this->_CoverImageAvifUrl)){
 			if(file_exists(WEB_ROOT . '/images/covers/' . $this->UrlSafeIdentifier . '-cover.avif')){
 				$this->_CoverImageAvifUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-cover.avif';
 			}
@@ -372,7 +377,7 @@ class Ebook{
 	}
 
 	protected function GetCoverImage2xUrl(): string{
-		if($this->_CoverImage2xUrl === null){
+		if(!isset($this->_CoverImage2xUrl)){
 			$this->_CoverImage2xUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-cover@2x.jpg';
 		}
 
@@ -380,7 +385,7 @@ class Ebook{
 	}
 
 	protected function GetCoverImage2xAvifUrl(): ?string{
-		if($this->_CoverImage2xAvifUrl === null){
+		if(!isset($this->_CoverImage2xAvifUrl)){
 			if(file_exists(WEB_ROOT . '/images/covers/' . $this->UrlSafeIdentifier . '-cover@2x.avif')){
 				$this->_CoverImage2xAvifUrl = '/images/covers/' . $this->UrlSafeIdentifier . '-' . $this->GetLatestCommitHash() . '-cover@2x.avif';
 			}
@@ -390,7 +395,7 @@ class Ebook{
 	}
 
 	protected function GetReadingEaseDescription(): string{
-		if($this->_ReadingEaseDescription === null){
+		if(!isset($this->_ReadingEaseDescription)){
 			if($this->ReadingEase > 89){
 				$this->_ReadingEaseDescription = 'very easy';
 			}
@@ -418,7 +423,7 @@ class Ebook{
 	}
 
 	protected function GetReadingTime(): string{
-		if($this->_ReadingTime === null){
+		if(!isset($this->_ReadingTime)){
 			$readingTime = ceil($this->WordCount / AVERAGE_READING_WORDS_PER_MINUTE);
 			$this->_ReadingTime = (string)$readingTime;
 
@@ -449,7 +454,7 @@ class Ebook{
 	}
 
 	protected function GetAuthorsHtml(): string{
-		if($this->_AuthorsHtml === null){
+		if(!isset($this->_AuthorsHtml)){
 			$this->_AuthorsHtml = Ebook::GenerateContributorList($this->Authors, true);
 		}
 
@@ -457,7 +462,7 @@ class Ebook{
 	}
 
 	protected function GetAuthorsUrl(): string{
-		if($this->_AuthorsUrl === null){
+		if(!isset($this->_AuthorsUrl)){
 			$this->_AuthorsUrl = preg_replace('|url:https://standardebooks.org/ebooks/([^/]+)/.*|ius', '/ebooks/\1', $this->Identifier);
 		}
 
@@ -465,7 +470,7 @@ class Ebook{
 	}
 
 	protected function GetContributorsHtml(): string{
-		if($this->_ContributorsHtml === null){
+		if(!isset($this->_ContributorsHtml)){
 			$this->_ContributorsHtml = '';
 			if(sizeof($this->Contributors) > 0){
 				$this->_ContributorsHtml .= ' with ' . Ebook::GenerateContributorList($this->Contributors, false) . ';';
@@ -492,7 +497,7 @@ class Ebook{
 	}
 
 	protected function GetTitleWithCreditsHtml(): string{
-		if($this->_TitleWithCreditsHtml === null){
+		if(!isset($this->_TitleWithCreditsHtml)){
 			$titleContributors = '';
 			if(sizeof($this->Contributors) > 0){
 				$titleContributors .= '. With ' . Ebook::GenerateContributorList($this->Contributors, false);
@@ -513,7 +518,7 @@ class Ebook{
 	}
 
 	protected function GetTextUrl(): string{
-		if($this->_TextUrl === null){
+		if(!isset($this->_TextUrl)){
 			$this->_TextUrl = $this->Url . '/text';
 		}
 
@@ -521,7 +526,7 @@ class Ebook{
 	}
 
 	protected function GetTextSinglePageUrl(): string{
-		if($this->_TextSinglePageUrl === null){
+		if(!isset($this->_TextSinglePageUrl)){
 			$this->_TextSinglePageUrl = $this->Url . '/text/single-page';
 		}
 
@@ -529,7 +534,7 @@ class Ebook{
 	}
 
 	protected function GetTextSinglePageSizeFormatted(): string{
-		if($this->_TextSinglePageSizeFormatted === null){
+		if(!isset($this->_TextSinglePageSizeFormatted)){
 			$bytes = $this->TextSinglePageByteCount;
 			$sizes = array('B', 'KB', 'MB', 'GB', 'TB', 'PB');
 
@@ -551,7 +556,7 @@ class Ebook{
 	}
 
 	protected function GetIndexableText(): string{
-		if($this->_IndexableText === null){
+		if(!isset($this->_IndexableText)){
 			$this->_IndexableText = $this->FullTitle ?? $this->Title;
 
 			$this->_IndexableText .= ' ' . $this->AlternateTitle;
@@ -585,6 +590,11 @@ class Ebook{
 		return $this->_IndexableText;
 	}
 
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
 	/**
 	 * Construct an Ebook from a filesystem path.
 	 *
@@ -714,8 +724,8 @@ class Ebook{
 
 		$xml->registerXPathNamespace('dc', 'http://purl.org/dc/elements/1.1/');
 
-		$ebook->Title = Ebook::NullIfEmpty($xml->xpath('/package/metadata/dc:title'));
-		if($ebook->Title === null){
+		$ebook->Title = trim(Ebook::NullIfEmpty($xml->xpath('/package/metadata/dc:title')) ?? '');
+		if($ebook->Title == ''){
 			throw new Exceptions\EbookParsingException('Invalid <dc:title> element.');
 		}
 
@@ -808,14 +818,16 @@ class Ebook{
 				$fileAs = (string)$author;
 			}
 
-			$authors[] = Contributor::FromProperties(
-						(string)$author,
-						$fileAs,
-						Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:name.person.full-name"][@refines="#' . $id . '"]')),
-						Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.encyclopedia.wikipedia"][@refines="#' . $id . '"]')),
-						'aut',
-						Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.authority.nacoaf"][@refines="#' . $id . '"]'))
-					);
+			$contributor = new Contributor();
+			$contributor->Name = (string)$author;
+			$contributor->UrlName = Formatter::MakeUrlSafe($contributor->Name);
+			$contributor->SortName = $fileAs;
+			$contributor->FullName = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:name.person.full-name"][@refines="#' . $id . '"]'));
+			$contributor->WikipediaUrl = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.encyclopedia.wikipedia"][@refines="#' . $id . '"]'));
+			$contributor->MarcRole = 'aut';
+			$contributor->NacoafUrl = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.authority.nacoaf"][@refines="#' . $id . '"]'));
+
+			$authors[] = $contributor;
 		}
 		if(sizeof($authors) == 0){
 			throw new Exceptions\EbookParsingException('Invalid <dc:creator> element.');
@@ -833,14 +845,14 @@ class Ebook{
 			}
 
 			foreach($xml->xpath('/package/metadata/meta[ (@property="role" or @property="se:role") and @refines="#' . $id . '"]') ?: [] as $role){
-				$c = Contributor::FromProperties(
-							(string)$contributor,
-							Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="file-as"][@refines="#' . $id . '"]')),
-							Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:name.person.full-name"][@refines="#' . $id . '"]')),
-							Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.encyclopedia.wikipedia"][@refines="#' . $id . '"]')),
-							$role,
-							Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.authority.nacoaf"][@refines="#' . $id . '"]'))
-						);
+				$c = new Contributor();
+				$c->Name = (string)$contributor;
+				$c->UrlName = Formatter::MakeUrlSafe($contributor->Name);
+				$c->SortName = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="file-as"][@refines="#' . $id . '"]'));
+				$c->FullName = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:name.person.full-name"][@refines="#' . $id . '"]'));
+				$c->WikipediaUrl = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.encyclopedia.wikipedia"][@refines="#' . $id . '"]'));
+				$c->MarcRole = $role;
+				$c->NacoafUrl = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:url.authority.nacoaf"][@refines="#' . $id . '"]'));
 
 				// A display-sequence of 0 indicates that we don't want to process this contributor.
 				$displaySequence = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="display-seq"][@refines="#' . $id . '"]'));
@@ -875,9 +887,9 @@ class Ebook{
 		$ebook->Contributors = $contributors;
 
 		// Some basic data.
-		$ebook->Description = Ebook::NullIfEmpty($xml->xpath('/package/metadata/dc:description'));
-		$ebook->Language = Ebook::NullIfEmpty($xml->xpath('/package/metadata/dc:language'));
-		$ebook->LongDescription = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:long-description"]'));
+		$ebook->Description = Ebook::NullIfEmpty($xml->xpath('/package/metadata/dc:description')) ?? '';
+		$ebook->LongDescription = Ebook::NullIfEmpty($xml->xpath('/package/metadata/meta[@property="se:long-description"]')) ?? '';
+		$ebook->Language = Ebook::NullIfEmpty($xml->xpath('/package/metadata/dc:language')) ?? '';
 
 		$wordCount = 0;
 		$wordCountElement = $xml->xpath('/package/metadata/meta[@property="se:word-count"]');
@@ -1048,7 +1060,6 @@ class Ebook{
 			}
 		}
 
-
 		$this->KepubUrl = trim($this->KepubUrl ?? '');
 		if($this->KepubUrl == ''){
 			$this->KepubUrl = null;
@@ -1095,7 +1106,7 @@ class Ebook{
 		}
 
 		if(isset($this->Title)){
-			$this->Title = trim($this->Title ?? '');
+			$this->Title = trim($this->Title);
 
 			if($this->Title == ''){
 				$error->Add(new Exceptions\EbookTitleRequiredException());
@@ -1128,7 +1139,7 @@ class Ebook{
 		}
 
 		if(isset($this->Description)){
-			$this->Description = trim($this->Description ?? '');
+			$this->Description = trim($this->Description);
 
 			if($this->Description == ''){
 				$error->Add(new Exceptions\EbookDescriptionRequiredException());
@@ -1139,7 +1150,7 @@ class Ebook{
 		}
 
 		if(isset($this->LongDescription)){
-			$this->LongDescription = trim($this->LongDescription ?? '');
+			$this->LongDescription = trim($this->LongDescription);
 
 			if($this->LongDescription == ''){
 				$error->Add(new Exceptions\EbookLongDescriptionRequiredException());
@@ -1150,7 +1161,7 @@ class Ebook{
 		}
 
 		if(isset($this->Language)){
-			$this->Language = trim($this->Language ?? '');
+			$this->Language = trim($this->Language);
 
 			if($this->Language == ''){
 				$error->Add(new Exceptions\EbookLanguageRequiredException());
@@ -1520,8 +1531,9 @@ class Ebook{
 		return $string;
 	}
 
-
 	/**
+	 * If the given list of elements has an element that is not `''`, return that value; otherwise, return `null`.
+	 *
 	 * @param array<SimpleXMLElement>|false|null $elements
 	 */
 	private static function NullIfEmpty($elements): ?string{
@@ -1529,8 +1541,6 @@ class Ebook{
 			return null;
 		}
 
-		// Helper function when getting values from SimpleXml.
-		// Checks if the result is set, and returns the value if so; if the value is the empty string, return null.
 		if(isset($elements[0])){
 			$str = (string)$elements[0];
 			if($str !== ''){
@@ -1541,31 +1551,6 @@ class Ebook{
 		return null;
 	}
 
-	// ***********
-	// ORM METHODS
-	// ***********
-
-	/**
-	 * @throws Exceptions\EbookNotFoundException
-	 */
-	public static function GetByIdentifier(?string $identifier): Ebook{
-		if($identifier === null){
-			throw new Exceptions\EbookNotFoundException('Invalid identifier: ' . $identifier);
-		}
-
-		$result = Db::Query('
-				SELECT *
-				from Ebooks
-				where Identifier = ?
-			', [$identifier], Ebook::class);
-
-		if(sizeof($result) == 0){
-			throw new Exceptions\EbookNotFoundException('Invalid identifier: ' . $identifier);
-		}
-
-		return $result[0];
-	}
-
 	/**
 	 * @throws Exceptions\ValidationException
 	 */
@@ -1843,4 +1828,29 @@ class Ebook{
 			}
 		}
 	}
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
+	/**
+	 * @throws Exceptions\EbookNotFoundException
+	 */
+	public static function GetByIdentifier(?string $identifier): Ebook{
+		if($identifier === null){
+			throw new Exceptions\EbookNotFoundException('Invalid identifier: ' . $identifier);
+		}
+
+		$result = Db::Query('
+				SELECT *
+				from Ebooks
+				where Identifier = ?
+			', [$identifier], Ebook::class);
+
+		if(sizeof($result) == 0){
+			throw new Exceptions\EbookNotFoundException('Invalid identifier: ' . $identifier);
+		}
+
+		return $result[0];
+	}
 }
diff --git a/lib/EbookSource.php b/lib/EbookSource.php
index e417c409..46b1e9d1 100644
--- a/lib/EbookSource.php
+++ b/lib/EbookSource.php
@@ -3,18 +3,20 @@
 use Safe\DateTimeImmutable;
 
 class EbookSource{
-	public ?int $EbookId = null;
+	public int $EbookId;
 	public Enums\EbookSourceType $Type;
 	public string $Url;
-	public ?int $SortOrder = null;
+	public int $SortOrder;
+
+
+	// *******
+	// METHODS
+	// *******
 
 	/**
 	 * @throws Exceptions\ValidationException
 	 */
 	public function Validate(): void{
-		/** @throws void */
-		$now = new DateTimeImmutable();
-
 		$error = new Exceptions\ValidationException();
 
 		if(!isset($this->EbookId)){
diff --git a/lib/EbookTag.php b/lib/EbookTag.php
index c7814332..703e869b 100644
--- a/lib/EbookTag.php
+++ b/lib/EbookTag.php
@@ -4,25 +4,20 @@ class EbookTag extends Tag{
 		$this->Type = Enums\TagType::Ebook;
 	}
 
+
 	// *******
 	// GETTERS
 	// *******
-	protected function GetUrlName(): string{
-		if($this->_UrlName === null){
-			$this->_UrlName = Formatter::MakeUrlSafe($this->Name);
-		}
-
-		return $this->_UrlName;
-	}
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/subjects/' . $this->UrlName;
 		}
 
 		return $this->_Url;
 	}
 
+
 	// *******
 	// METHODS
 	// *******
@@ -43,6 +38,8 @@ class EbookTag extends Tag{
 			if(strlen($this->Name) > EBOOKS_MAX_STRING_LENGTH){
 				$error->Add(new Exceptions\StringTooLongException('Ebook tag: '. $this->Name));
 			}
+
+			$this->UrlName = Formatter::MakeUrlSafe($this->Name);
 		}
 		else{
 			$error->Add(new Exceptions\EbookTagNameRequiredException());
@@ -72,6 +69,11 @@ class EbookTag extends Tag{
 		$this->TagId = Db::GetLastInsertedId();
 	}
 
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
 	/**
 	 * @throws Exceptions\ValidationException
 	 */
diff --git a/lib/Exceptions/ArtworkTagNameRequiredException.php b/lib/Exceptions/ArtworkTagNameRequiredException.php
new file mode 100644
index 00000000..0380cf89
--- /dev/null
+++ b/lib/Exceptions/ArtworkTagNameRequiredException.php
@@ -0,0 +1,7 @@
+<?
+namespace Exceptions;
+
+class ArtworkTagNameRequiredException extends AppException{
+	/** @var string $message */
+	protected $message = 'Tag name is required.';
+}
diff --git a/lib/Feed.php b/lib/Feed.php
index 25433f11..0eb9b860 100644
--- a/lib/Feed.php
+++ b/lib/Feed.php
@@ -14,8 +14,8 @@ abstract class Feed{
 	public $Entries = [];
 	public string $Path;
 	public ?string $Stylesheet = null;
-	protected ?string $XmlString = null;
-	public ?DateTimeImmutable $Updated = null;
+	protected string $_XmlString;
+	public DateTimeImmutable $Updated;
 
 	/**
 	 * @param string $title
@@ -31,6 +31,13 @@ abstract class Feed{
 	}
 
 
+	// *******
+	// GETTERS
+	// *******
+
+	abstract protected function GetXmlString(): string;
+
+
 	// *******
 	// METHODS
 	// *******
@@ -52,11 +59,6 @@ abstract class Feed{
 		return $output;
 	}
 
-	protected function GetXmlString(): string{
-		// Virtual function, meant to be implemented by subclass
-		return '';
-	}
-
 	public function Save(): void{
 		$feed = $this->GetXmlString();
 
diff --git a/lib/GitCommit.php b/lib/GitCommit.php
index 9ea2fa8f..01927938 100644
--- a/lib/GitCommit.php
+++ b/lib/GitCommit.php
@@ -2,11 +2,16 @@
 use Safe\DateTimeImmutable;
 
 class GitCommit{
-	public ?int $EbookId = null;
+	public int $EbookId;
 	public DateTimeImmutable $Created;
 	public string $Message;
 	public string $Hash;
 
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
 	/**
 	 * @throws Exceptions\InvalidGitCommitException
 	 */
@@ -26,6 +31,11 @@ class GitCommit{
 		return $instance;
 	}
 
+
+	// *******
+	// METHODS
+	// *******
+
 	/**
 	 * @throws Exceptions\ValidationException
 	 */
diff --git a/lib/Image.php b/lib/Image.php
index 253ab758..67c2f05b 100644
--- a/lib/Image.php
+++ b/lib/Image.php
@@ -62,7 +62,7 @@ class Image{
 				unlink($tempFilename);
 			}
 			catch(Exception){
-				// Pass if file doesn't exist
+				// Pass if file doesn't exist.
 			}
 		}
 
diff --git a/lib/Library.php b/lib/Library.php
index 8fdda6fe..dcafc582 100644
--- a/lib/Library.php
+++ b/lib/Library.php
@@ -5,15 +5,13 @@ use function Safe\exec;
 use function Safe\filemtime;
 use function Safe\filesize;
 use function Safe\glob;
-use function Safe\ksort;
 use function Safe\preg_replace;
 use function Safe\preg_split;
-use function Safe\sprintf;
-use function Safe\usort;
 
 class Library{
 	/**
 	* @param array<string> $tags
+	*
 	* @return array{ebooks: array<Ebook>, ebooksCount: int}
 	*/
 	public static function FilterEbooks(string $query = null, array $tags = [], Enums\EbookSortType $sort = null, int $page = 1, int $perPage = EBOOKS_PER_PAGE): array{
@@ -102,11 +100,11 @@ class Library{
 				', [$urlPath], Ebook::class);
 		}
 		else{
-			// Multiple authors, e.g., karl-marx_friedrich-engels
+			// Multiple authors, e.g., `karl-marx_friedrich-engels`.
 			$authors = explode('_', $urlPath);
 
 			$params = $authors;
-			$params[] = sizeof($authors); // The number of authors in the URL must match the number of Contributor records.
+			$params[] = sizeof($authors); // The number of authors in the URL must match the number of `Contributor` records.
 
 			return Db::Query('
 					SELECT e.*
@@ -123,6 +121,7 @@ class Library{
 
 	/**
 	 * @return array<Collection>
+	 *
 	 * @throws Exceptions\AppException
 	 */
 	public static function GetEbookCollections(): array{
@@ -135,7 +134,10 @@ class Library{
 		if($collator === null){
 			throw new Exceptions\AppException('Couldn\'t create collator object when getting collections.');
 		}
-		usort($collections, function($a, $b) use($collator){ return $collator->compare($a->GetSortedName(), $b->GetSortedName()); });
+		usort($collections, function(Collection $a, Collection $b) use($collator){
+			$result = $collator->compare($a->GetSortedName(), $b->GetSortedName());
+			return $result === false ? 0 : $result;
+		});
 		return $collections;
 	}
 
@@ -344,6 +346,7 @@ class Library{
 
 	/**
 	 * @return array<Artwork>
+	 *
 	 * @throws Exceptions\ArtistNotFoundException
 	 */
 	public static function GetArtworksByArtist(?string $artistUrlName, ?string $status, ?int $submitterUserId): array{
@@ -451,7 +454,8 @@ class Library{
 
 	/**
 	 * @param array<int, stdClass> $items
-	 * @return array<string, array<int|string, array<int|string, mixed>>>
+	 *
+	 * @return array<int, stdClass>
 	 */
 	private static function SortBulkDownloads(array $items): array{
 		// This sorts our items in a special order, epub first and advanced epub last
@@ -481,7 +485,8 @@ class Library{
 	}
 
 	/**
-	 * @return array<string, array<int|string, array<int|string, stdClass>>>
+	 * @return array{'months': array<string, array<string, stdClass>>, 'subjects': array<stdClass>, 'collections': array<stdClass>, 'authors': array<stdClass>}
+	 *
 	 * @throws Exceptions\AppException
 	 */
 	public static function RebuildBulkDownloadsCache(): array{
@@ -489,6 +494,7 @@ class Library{
 		if($collator === null){
 			throw new Exceptions\AppException('Couldn\'t create collator object when rebuilding bulk download cache.');
 		}
+		/** @var array<string, array<string, stdClass>> $months */
 		$months = [];
 		$subjects = [];
 		$collections = [];
@@ -509,6 +515,8 @@ class Library{
 			catch(\Exception){
 				throw new Exceptions\AppException('Couldn\'t parse date on bulk download object.');
 			}
+
+			/** @var string $year Required to satisfy PHPStan */
 			$year = $date->format('Y');
 			$month = $date->format('F');
 
@@ -533,7 +541,10 @@ class Library{
 		foreach(glob(WEB_ROOT . '/bulk-downloads/collections/*/', GLOB_NOSORT) as $dir){
 			$collections[] = self::FillBulkDownloadObject($dir, 'collections', '/collections');
 		}
-		usort($collections, function($a, $b) use($collator){ return $collator->compare($a->LabelSort, $b->LabelSort); });
+		usort($collections, function(stdClass $a, stdClass $b) use($collator): int{
+			$result = $collator->compare($a->LabelSort, $b->LabelSort);
+			return $result === false ? 0 : $result;
+		});
 
 		apcu_store('bulk-downloads-collections', $collections, 43200); // 12 hours
 
@@ -541,7 +552,10 @@ class Library{
 		foreach(glob(WEB_ROOT . '/bulk-downloads/authors/*/', GLOB_NOSORT) as $dir){
 			$authors[] = self::FillBulkDownloadObject($dir, 'authors', '/ebooks');
 		}
-		usort($authors, function($a, $b) use($collator){ return $collator->compare($a->LabelSort, $b->LabelSort); });
+		usort($authors, function(stdClass $a, stdClass $b) use($collator): int{
+			$result = $collator->compare($a->LabelSort, $b->LabelSort);
+			return $result === false ? 0 : $result;
+		});
 
 		apcu_store('bulk-downloads-authors', $authors, 43200); // 12 hours
 
@@ -549,7 +563,8 @@ class Library{
 	}
 
 	/**
-	 * @return array<string, array<int|string, array<int|string, mixed>>>
+	 * @return array<stdClass>
+	 *
 	 * @throws Exceptions\AppException
 	 */
 	public static function RebuildFeedsCache(?string $returnType = null, ?string $returnClass = null): ?array{
@@ -584,7 +599,10 @@ class Library{
 					$feeds[] = $obj;
 				}
 
-				usort($feeds, function($a, $b) use($collator){ return $collator->compare($a->LabelSort, $b->LabelSort); });
+				usort($feeds, function(stdClass $a, stdClass $b) use($collator): int{
+					$result = $collator->compare($a->LabelSort, $b->LabelSort);
+					return $result === false ? 0 : $result;
+				});
 
 				if($type == $returnType && $class == $returnClass){
 					$retval = $feeds;
diff --git a/lib/LocSubject.php b/lib/LocSubject.php
index ce161e18..c7354630 100644
--- a/lib/LocSubject.php
+++ b/lib/LocSubject.php
@@ -3,6 +3,10 @@ class LocSubject{
 	public int $LocSubjectId;
 	public string $Name;
 
+	// *******
+	// METHODS
+	// *******
+
 	/**
 	 * @throws Exceptions\ValidationException
 	 */
diff --git a/lib/Log.php b/lib/Log.php
index 4c805597..d3204e88 100644
--- a/lib/Log.php
+++ b/lib/Log.php
@@ -1,5 +1,4 @@
 <?
-use Safe\DateTimeImmutable;
 use function Safe\fopen;
 use function Safe\fwrite;
 use function Safe\fclose;
diff --git a/lib/Manual.php b/lib/Manual.php
index 4ec7a694..68c0112a 100644
--- a/lib/Manual.php
+++ b/lib/Manual.php
@@ -1,9 +1,12 @@
 <?
 use function Safe\glob;
 use function Safe\preg_match_all;
-use function Safe\sort;
 
 class Manual{
+	// *******
+	// METHODS
+	// *******
+
 	public static function GetLatestVersion(): string{
 		$dirs = glob(MANUAL_PATH . '/*', GLOB_ONLYDIR);
 		sort($dirs);
diff --git a/lib/Museum.php b/lib/Museum.php
index 302d9a5d..8190779a 100644
--- a/lib/Museum.php
+++ b/lib/Museum.php
@@ -10,6 +10,11 @@ class Museum{
 	public string $Name;
 	public string $Domain;
 
+
+	// *******
+	// METHODS
+	// *******
+
 	/**
 	 * @throws Exceptions\InvalidUrlException
 	 * @throws Exceptions\InvalidMuseumUrlException
@@ -597,6 +602,10 @@ class Museum{
 		return $outputUrl;
 	}
 
+	// ***********
+	// ORM METHODS
+	// ***********
+
 	/**
 	* @throws Exceptions\MuseumNotFoundException
 	* @throws Exceptions\InvalidUrlException
diff --git a/lib/NewsletterSubscription.php b/lib/NewsletterSubscription.php
index fe2dd10c..85b5a127 100644
--- a/lib/NewsletterSubscription.php
+++ b/lib/NewsletterSubscription.php
@@ -13,15 +13,17 @@ class NewsletterSubscription{
 	public bool $IsSubscribedToNewsletter = false;
 	public ?int $UserId = null;
 	public DateTimeImmutable $Created;
-	protected ?User $_User = null;
-	protected ?string $_Url = null;
+
+	protected ?User $_User;
+	protected string $_Url;
+
 
 	// *******
 	// GETTERS
 	// *******
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/newsletter/subscriptions/' . $this->User->Uuid;
 		}
 
diff --git a/lib/OpdsAcquisitionFeed.php b/lib/OpdsAcquisitionFeed.php
index ac4c79fa..9c775b5e 100644
--- a/lib/OpdsAcquisitionFeed.php
+++ b/lib/OpdsAcquisitionFeed.php
@@ -13,10 +13,10 @@ class OpdsAcquisitionFeed extends OpdsFeed{
 	// *******
 
 	protected function GetXmlString(): string{
-		if($this->XmlString === null){
-			$this->XmlString = $this->CleanXmlString(Template::OpdsAcquisitionFeed(['id' => $this->Id, 'url' => $this->Url, 'title' => $this->Title, 'parentUrl' => $this->Parent ? $this->Parent->Url : null, 'updated' => $this->Updated, 'isCrawlable' => $this->IsCrawlable, 'subtitle' => $this->Subtitle, 'entries' => $this->Entries]));
+		if(!isset($this->_XmlString)){
+			$this->_XmlString = $this->CleanXmlString(Template::OpdsAcquisitionFeed(['id' => $this->Id, 'url' => $this->Url, 'title' => $this->Title, 'parentUrl' => $this->Parent ? $this->Parent->Url : null, 'updated' => $this->Updated, 'isCrawlable' => $this->IsCrawlable, 'subtitle' => $this->Subtitle, 'entries' => $this->Entries]));
 		}
 
-		return $this->XmlString;
+		return $this->_XmlString;
 	}
 }
diff --git a/lib/OpdsFeed.php b/lib/OpdsFeed.php
index 66c699f0..d400122e 100644
--- a/lib/OpdsFeed.php
+++ b/lib/OpdsFeed.php
@@ -36,7 +36,7 @@ abstract class OpdsFeed extends AtomFeed{
 
 		$this->Updated = $updated;
 
-		$this->XmlString = null;
+		unset($this->_XmlString);
 		file_put_contents($this->Path, $this->GetXmlString());
 
 		// Do we have any parents of our own to update?
diff --git a/lib/OpdsNavigationEntry.php b/lib/OpdsNavigationEntry.php
index 44ccea13..5fd6dcf6 100644
--- a/lib/OpdsNavigationEntry.php
+++ b/lib/OpdsNavigationEntry.php
@@ -6,12 +6,12 @@ class OpdsNavigationEntry{
 	public string $Url;
 	public string $Rel;
 	public string $Type;
-	public ?DateTimeImmutable $Updated = null;
+	public DateTimeImmutable $Updated;
 	public string $Description;
 	public string $Title;
 	public string $SortTitle;
 
-	public function __construct(string $title, string $description, string $url, ?DateTimeImmutable $updated, string $rel, string $type){
+	public function __construct(string $title, string $description, string $url, DateTimeImmutable $updated, string $rel, string $type){
 		$this->Id = SITE_URL . $url;
 		$this->Url = $url;
 		$this->Rel = $rel;
diff --git a/lib/OpdsNavigationFeed.php b/lib/OpdsNavigationFeed.php
index 03aec048..f6a0c4da 100644
--- a/lib/OpdsNavigationFeed.php
+++ b/lib/OpdsNavigationFeed.php
@@ -38,10 +38,10 @@ class OpdsNavigationFeed extends OpdsFeed{
 	// *******
 
 	protected function GetXmlString(): string{
-		if($this->XmlString === null){
-			$this->XmlString = $this->CleanXmlString(Template::OpdsNavigationFeed(['id' => $this->Id, 'url' => $this->Url, 'title' => $this->Title, 'parentUrl' => $this->Parent ? $this->Parent->Url : null, 'updated' => $this->Updated, 'subtitle' => $this->Subtitle, 'entries' => $this->Entries]));
+		if(!isset($this->_XmlString)){
+			$this->_XmlString = $this->CleanXmlString(Template::OpdsNavigationFeed(['id' => $this->Id, 'url' => $this->Url, 'title' => $this->Title, 'parentUrl' => $this->Parent ? $this->Parent->Url : null, 'updated' => $this->Updated, 'subtitle' => $this->Subtitle, 'entries' => $this->Entries]));
 		}
 
-		return $this->XmlString;
+		return $this->_XmlString;
 	}
 }
diff --git a/lib/Patron.php b/lib/Patron.php
index 381224b1..1d95137a 100644
--- a/lib/Patron.php
+++ b/lib/Patron.php
@@ -7,14 +7,15 @@ use Safe\DateTimeImmutable;
 class Patron{
 	use Traits\Accessor;
 
-	public ?int $UserId = null;
+	public int $UserId;
 	public bool $IsAnonymous;
 	public ?string $AlternateName = null;
 	public bool $IsSubscribedToEmails;
-	public ?DateTimeImmutable $Created = null;
+	public DateTimeImmutable $Created;
 	public ?DateTimeImmutable $Ended = null;
 
-	protected ?User $_User = null;
+	protected User $_User;
+
 
 	// *******
 	// METHODS
diff --git a/lib/Payment.php b/lib/Payment.php
index e39a94ff..ee983797 100644
--- a/lib/Payment.php
+++ b/lib/Payment.php
@@ -19,6 +19,11 @@ class Payment{
 
 	protected ?User $_User = null;
 
+
+	// *******
+	// GETTERS
+	// *******
+
 	/**
 	 * @throws Exceptions\UserNotFoundException
 	 */
diff --git a/lib/Poll.php b/lib/Poll.php
index 061aff5d..830e71fd 100644
--- a/lib/Poll.php
+++ b/lib/Poll.php
@@ -1,6 +1,5 @@
 <?
 use Safe\DateTimeImmutable;
-use function Safe\usort;
 
 /**
  * @property string $Url
@@ -18,12 +17,13 @@ class Poll{
 	public DateTimeImmutable $Created;
 	public DateTimeImmutable $Start;
 	public DateTimeImmutable $End;
-	protected ?string $_Url = null;
-	/** @var ?array<PollItem> $_PollItems */
-	protected $_PollItems = null;
-	/** @var ?array<PollItem> $_PollItemsByWinner */
-	protected $_PollItemsByWinner = null;
-	protected ?int $_VoteCount = null;
+
+	protected string $_Url;
+	/** @var array<PollItem> $_PollItems */
+	protected array $_PollItems;
+	/** @var array<PollItem> $_PollItemsByWinner */
+	protected array $_PollItemsByWinner;
+	protected int $_VoteCount;
 
 
 	// *******
@@ -31,7 +31,7 @@ class Poll{
 	// *******
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/polls/' . $this->UrlName;
 		}
 
@@ -39,7 +39,7 @@ class Poll{
 	}
 
 	protected function GetVoteCount(): int{
-		if($this->_VoteCount === null){
+		if(!isset($this->_VoteCount)){
 			$this->_VoteCount = Db::QueryInt('
 							SELECT count(*)
 							from PollVotes pv
@@ -55,7 +55,7 @@ class Poll{
 	 * @return array<PollItem>
 	 */
 	protected function GetPollItems(): array{
-		if($this->_PollItems === null){
+		if(!isset($this->_PollItems)){
 			$this->_PollItems = Db::Query('
 							SELECT *
 							from PollItems
@@ -71,11 +71,11 @@ class Poll{
 	 * @return array<PollItem>
 	 */
 	protected function GetPollItemsByWinner(): array{
-		if($this->_PollItemsByWinner === null){
+		if(!isset($this->_PollItemsByWinner)){
 			$this->_PollItemsByWinner = $this->PollItems;
 			usort($this->_PollItemsByWinner, function(PollItem $a, PollItem $b){ return $a->VoteCount <=> $b->VoteCount; });
 
-			$this->_PollItemsByWinner = array_reverse($this->_PollItemsByWinner ?? []);
+			$this->_PollItemsByWinner = array_reverse($this->_PollItemsByWinner);
 		}
 
 		return $this->_PollItemsByWinner;
@@ -87,7 +87,6 @@ class Poll{
 	// *******
 
 	public function IsActive(): bool{
-		/** @throws void */
 		if( ($this->Start !== null && $this->Start > NOW) || ($this->End !== null && $this->End < NOW)){
 			return false;
 		}
diff --git a/lib/PollItem.php b/lib/PollItem.php
index 7dc27dee..1a841a9e 100644
--- a/lib/PollItem.php
+++ b/lib/PollItem.php
@@ -1,7 +1,4 @@
 <?
-
-use Exceptions\PollItemNotFoundException;
-
 /**
  * @property int $VoteCount
  * @property Poll $Poll
@@ -13,8 +10,9 @@ class PollItem{
 	public int $PollId;
 	public string $Name;
 	public string $Description;
-	protected ?int $_VoteCount = null;
-	protected ?Poll $_Poll = null;
+
+	protected int $_VoteCount;
+	protected Poll $_Poll;
 
 
 	// *******
@@ -22,7 +20,7 @@ class PollItem{
 	// *******
 
 	protected function GetVoteCount(): int{
-		if($this->_VoteCount === null){
+		if(!isset($this->_VoteCount)){
 			$this->_VoteCount = Db::QueryInt('
 							SELECT count(*)
 							from PollVotes pv
diff --git a/lib/PollVote.php b/lib/PollVote.php
index c300ef43..b40a845e 100644
--- a/lib/PollVote.php
+++ b/lib/PollVote.php
@@ -8,14 +8,15 @@ use Safe\DateTimeImmutable;
  */
 class PollVote{
 	use Traits\Accessor;
+	use Traits\PropertyFromHttp;
 
-	public ?int $UserId = null;
+	public int $UserId;
 	public DateTimeImmutable $Created;
-	public ?int $PollItemId = null;
+	public int $PollItemId;
 
-	protected ?User $_User = null;
-	protected ?PollItem $_PollItem = null;
-	protected ?string $_Url = null;
+	protected User $_User;
+	protected PollItem $_PollItem;
+	protected string $_Url;
 
 
 	// *******
@@ -23,7 +24,7 @@ class PollVote{
 	// *******
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = $this->PollItem->Poll->Url . '/votes/' . $this->UserId;
 		}
 
@@ -41,26 +42,30 @@ class PollVote{
 	protected function Validate(): void{
 		$error = new Exceptions\InvalidPollVoteException();
 
-		if($this->User === null){
+		if(!isset($this->UserId)){
 			$error->Add(new Exceptions\UserNotFoundException());
 		}
+		else{
+			try{
+				// Attempt to get the `User`.
+				User::Get($this->UserId);
+			}
+			catch(Exceptions\UserNotFoundException $ex){
+				$error->Add($ex);
+			}
+		}
 
-		if($this->PollItemId === null){
+		if(!isset($this->PollItemId)){
 			$error->Add(new Exceptions\PollItemRequiredException());
 		}
 		else{
-			if($this->PollItem === null){
-				$error->Add(new Exceptions\PollNotFoundException());
+			try{
+				if(!$this->PollItem->Poll->IsActive()){
+					$error->Add(new Exceptions\PollClosedException());
+				}
 			}
-			else{
-				if($this->PollItem->Poll === null){
-					$error->Add(new Exceptions\PollNotFoundException());
-				}
-				else{
-					if(!$this->PollItem->Poll->IsActive()){
-						$error->Add(new Exceptions\PollClosedException());
-					}
-				}
+			catch(Exceptions\PollItemNotFoundException | Exceptions\PollNotFoundException){
+				$error->Add(new Exceptions\PollNotFoundException());
 			}
 		}
 
@@ -97,10 +102,8 @@ class PollVote{
 				$this->UserId = $this->User->UserId;
 			}
 			catch(Exceptions\UserNotFoundException){
-				// Can't validate patron email - do nothing for now,
-				// this will be caught later when we validate the vote during creation.
-				// Save the email in the User object in case we want it later,
-				// for example prefilling the 'create' form after an error is returned.
+				// Can't validate patron email - do nothing for now, this will be caught later when we validate the vote during creation.
+				// Save the email in the User object in case we want it later, for example prefilling the 'create' form after an error is returned.
 				$this->User = new User();
 				$this->User->Email = $email;
 			}
@@ -135,4 +138,8 @@ class PollVote{
 
 		return $result[0] ?? throw new Exceptions\PollVoteNotFoundException();
 	}
+
+	public function FillFromHttpPost(): void{
+		$this->PropertyFromHttp('PollItemId');
+	}
 }
diff --git a/lib/RssFeed.php b/lib/RssFeed.php
index 5783bab6..f12c3c05 100644
--- a/lib/RssFeed.php
+++ b/lib/RssFeed.php
@@ -21,13 +21,13 @@ class RssFeed extends Feed{
 	// *******
 
 	protected function GetXmlString(): string{
-		if($this->XmlString === null){
+		if(!isset($this->_XmlString)){
 			$feed = Template::RssFeed(['url' => $this->Url, 'description' => $this->Description, 'title' => $this->Title, 'entries' => $this->Entries, 'updated' => NOW]);
 
-			$this->XmlString = $this->CleanXmlString($feed);
+			$this->_XmlString = $this->CleanXmlString($feed);
 		}
 
-		return $this->XmlString;
+		return $this->_XmlString;
 	}
 
 	public function SaveIfChanged(): bool{
diff --git a/lib/Session.php b/lib/Session.php
index 3ca8a9bc..a04cec31 100644
--- a/lib/Session.php
+++ b/lib/Session.php
@@ -13,8 +13,8 @@ class Session{
 	public DateTimeImmutable $Created;
 	public string $SessionId;
 
-	protected ?User $_User = null;
-	public ?string $_Url = null;
+	protected User $_User;
+	public string $_Url;
 
 
 	// *******
@@ -22,7 +22,7 @@ class Session{
 	// *******
 
 	protected function GetUrl(): string{
-		if($this->_Url === null){
+		if(!isset($this->_Url)){
 			$this->_Url = '/sessions/' . $this->SessionId;
 		}
 
@@ -101,6 +101,11 @@ class Session{
 		setcookie('sessionid', $sessionId, ['expires' => intval((new DateTimeImmutable('+1 week'))->format(Enums\DateTimeFormat::UnixTimestamp->value)), 'path' => '/', 'domain' => SITE_DOMAIN, 'secure' => true, 'httponly' => false, 'samesite' => 'Lax']); // Expires in two weeks
 	}
 
+
+	// ***********
+	// ORM METHODS
+	// ***********
+
 	/**
 	 * @throws Exceptions\SessionNotFoundException
 	 */
diff --git a/lib/Tag.php b/lib/Tag.php
index e8a0394b..b36e392a 100644
--- a/lib/Tag.php
+++ b/lib/Tag.php
@@ -1,14 +1,14 @@
 <?
 /**
  * @property string $Url
- * @property string $UrlName
  */
 class Tag{
 	use Traits\Accessor;
 
 	public int $TagId;
 	public string $Name;
+	public string $UrlName;
 	public Enums\TagType $Type;
-	protected ?string $_UrlName = null;
-	protected ?string $_Url = null;
+
+	protected string $_Url;
 }
diff --git a/lib/Traits/Accessor.php b/lib/Traits/Accessor.php
index 1913cdfc..a9cd2b22 100644
--- a/lib/Traits/Accessor.php
+++ b/lib/Traits/Accessor.php
@@ -117,6 +117,7 @@ trait Accessor{
 	 * $t->User = new User();
 	 *
 	 * isset($t->User); // true
+	 * ```
 	 *
 	 * @see <https://reddit.com/r/PHPhelp/comments/x2avqu/anyone_know_the_rules_behind_null_coalescing/>
 	 */
diff --git a/lib/Traits/PropertyFromHttp.php b/lib/Traits/PropertyFromHttp.php
new file mode 100644
index 00000000..3cf629c6
--- /dev/null
+++ b/lib/Traits/PropertyFromHttp.php
@@ -0,0 +1,154 @@
+<?
+namespace Traits;
+
+use function Safe\preg_replace;
+
+trait PropertyFromHttp{
+	/**
+	 * Given the string name of a property, try to fill it from HTTP data (POST by default).
+	 *
+	 * This function will try to infer the type of the class property using reflection.
+	 *
+	 * - If a variable doesn't match a class property (either by name or by type), then the class property is unchanged.
+	 *
+	 * - If a variable matches a class property both by name and type, then the class property is set to the variable.
+	 *
+	 * - If the class property type is both nullable and not `string` (e.g., the class property is `?int`), then a matching but empty variable will set that class property to `null`; this includes `?string` class properties. (I.e., a matching variable of value `""` will set a `?string` class property to `null`.)
+	 *
+	 * For example, consider:
+	 *
+	 * ```
+	 * class Test{
+	 * 	use Traits\PropertyFromHttp;
+	 *
+	 * 	public int $Id;
+	 * 	public string $Name;
+	 * 	public ?string $Description;
+	 * 	public ?int $ChapterNumber;
+	 * }
+	 * ```
+	 *
+	 * - POST `['test-foo' => 'bar']`:
+	 *
+	 * 	No changes
+	 *
+	 * - POST `['test-id' => '123']`:
+	 *
+	 * 	`$Id`: set to `123`
+	 *
+	 * - POST `['test-id' => '']`:
+	 *
+	 * 	`$Id`: unchanged, because it is not nullable
+	 *
+	 * - POST `['test-name' => 'bob']`:
+	 *
+	 * 	`$Name`: set to `"bob"`
+	 *
+	 * - POST `['test-name' => '']`:
+	 *
+	 * 	`$Name`: set to `""`, because it is not nullable
+	 *
+	 * - POST `['test-description' => 'abc']`:
+	 *
+	 * 	`$Description`: set to `abc`
+	 *
+	 * - POST `['test-description' => '']`:
+	 *
+	 * 	`$Description`: set to `null`, because it is nullable
+	 *
+	 * - POST `['test-chapter-number' => '456']`:
+	 *
+	 * 	`$ChapterNumber`: set to `456`
+	 *
+	 * - POST `['test-chapter-number' => '']`:
+	 *
+	 * 	`$ChapterNumber`: set to `null`, because an empty string sets nullable properties to `null`.
+	 */
+	public function PropertyFromHttp(string $property, \Enums\HttpVariableSource $set = POST, ?string $httpName = null): void{
+		try{
+			$rp = new \ReflectionProperty($this, $property);
+		}
+		catch(\ReflectionException){
+			return;
+		}
+
+		/** @var ?\ReflectionNamedType $propertyType */
+		$propertyType = $rp->getType();
+		if($propertyType !== null){
+			if($httpName === null){
+				$httpName = mb_strtolower(preg_replace('/([^^])([A-Z])/u', '\1-\2', $this::class . $property));
+			}
+
+			$vars = [];
+
+			switch($set){
+				case \Enums\HttpVariableSource::Get:
+					$vars = $_GET;
+					break;
+				case \Enums\HttpVariableSource::Post:
+					$vars = $_POST;
+					break;
+				case \Enums\HttpVariableSource::Cookie:
+					$vars = $_COOKIE;
+					break;
+				case \Enums\HttpVariableSource::Session:
+					$vars = $_SESSION;
+					break;
+			}
+
+			// If the variable was not passed to us, don't change the property.
+			if(!isset($vars[$httpName])){
+				return;
+			}
+
+			$type = $propertyType->getName();
+			$isPropertyNullable = $propertyType->allowsNull();
+			$isPropertyEnum = is_a($type, 'BackedEnum', true);
+			$postValue = null;
+
+			if($isPropertyEnum){
+				$postValue = $type::tryFrom(\HttpInput::Str($set, $httpName) ?? '');
+			}
+			else{
+				switch($type){
+					case 'int':
+						$postValue = \HttpInput::Int($set, $httpName);
+						break;
+					case 'bool':
+						$postValue = \HttpInput::Bool($set, $httpName);
+						break;
+					case 'float':
+						$postValue = \HttpInput::Dec($set, $httpName);
+						break;
+					case 'DateTimeImmutable':
+					case 'Safe\DateTimeImmutable':
+						$postValue = \HttpInput::Date($set, $httpName);
+						break;
+					case 'array':
+						$postValue = \HttpInput::Array($set, $httpName);
+						break;
+					case 'string':
+						$postValue = \HttpInput::Str($set, $httpName, true);
+						break;
+				}
+			}
+
+			if($type == 'string'){
+				if($isPropertyNullable){
+					if($postValue == ''){
+						$this->{$property} = null;
+					}
+					else{
+						$this->{$property} = $postValue;
+					}
+				}
+				elseif($postValue !== null){
+					$this->{$property} = $postValue;
+				}
+			}
+			elseif($isPropertyNullable || $postValue !== null){
+				$this->{$property} = $postValue;
+			}
+		}
+	}
+}
diff --git a/lib/User.php b/lib/User.php
index 78f85189..3574518e 100644
--- a/lib/User.php
+++ b/lib/User.php
@@ -17,10 +17,11 @@ class User{
 	public string $Uuid;
 	public ?string $PasswordHash = null;
 
-	protected ?bool $_IsRegistered = null;
-	/** @var ?array<Payment> $_Payments */
-	protected $_Payments = null;
-	protected ?Benefits $_Benefits = null;
+	protected bool $_IsRegistered;
+	/** @var array<Payment> $_Payments */
+	protected array $_Payments;
+	protected Benefits $_Benefits;
+
 
 	// *******
 	// GETTERS
@@ -30,7 +31,7 @@ class User{
 	* @return array<Payment>
 	*/
 	protected function GetPayments(): array{
-		if($this->_Payments === null){
+		if(!isset($this->_Payments)){
 			$this->_Payments = Db::Query('
 							SELECT *
 							from Payments
@@ -43,7 +44,7 @@ class User{
 	}
 
 	protected function GetBenefits(): Benefits{
-		if($this->_Benefits === null){
+		if(!isset($this->_Benefits)){
 			$result = Db::Query('
 						SELECT *
 						from Benefits
@@ -64,7 +65,7 @@ class User{
 	}
 
 	protected function GetIsRegistered(): ?bool{
-		if($this->_IsRegistered === null){
+		if(!isset($this->_IsRegistered)){
 			// A user is "registered" if they have a benefits entry in the table.
 			// This function will fill it out for us.
 			$this->GetBenefits();
diff --git a/scripts/generate-feeds b/scripts/generate-feeds
index 1bc6885b..aefc2a19 100755
--- a/scripts/generate-feeds
+++ b/scripts/generate-feeds
@@ -46,12 +46,7 @@ function CreateOpdsCollectionFeed(string $name, string $url, string $description
 
 	usort($collections, function($a, $b) use($collator){
 		$result = $collator->compare($a['sortedname'], $b['sortedname']);
-		if($result === false){
-			return 0;
-		}
-		else{
-			return $result;
-		}
+		return $result === false ? 0 : $result;
 	});
 
 	// Create the collections navigation document.
diff --git a/scripts/process-pending-payments b/scripts/process-pending-payments
index fc742b81..6be87dbf 100755
--- a/scripts/process-pending-payments
+++ b/scripts/process-pending-payments
@@ -208,7 +208,7 @@ try{
 					)
 				){
 					// This payment is eligible for the Patrons Circle!
-					if($payment->User !== null){
+					if($payment->UserId !== null && $payment->User !== null){
 						// Are we already a patron?
 						if(!Db::QueryBool('
 								SELECT exists(
diff --git a/templates/ArtworkForm.php b/templates/ArtworkForm.php
index 6d40e958..64e42e7d 100644
--- a/templates/ArtworkForm.php
+++ b/templates/ArtworkForm.php
@@ -34,10 +34,10 @@ $isEditForm = $isEditForm ?? false;
 	<label class="year">
 		<span>Year of death</span>
 		<span>If circa or unknown, enter the latest possible year.</span>
-		<? /* Not using <input type="number"> for now, see https://technology.blog.gov.uk/2020/02/24/why-the-gov-uk-design-system-team-changed-the-input-type-for-numbers/ */ ?>
+		<? /* Not using `<input type="number">` for now, see <https://technology.blog.gov.uk/2020/02/24/why-the-gov-uk-design-system-team-changed-the-input-type-for-numbers/>. */ ?>
 		<input
 			type="text"
-			name="artist-year-of-death"
+			name="artist-death-year"
 			inputmode="numeric"
 			pattern="[0-9]{1,4}"
 			value="<?= Formatter::EscapeHtml((string)$artwork->Artist->DeathYear) ?>"
@@ -56,7 +56,7 @@ $isEditForm = $isEditForm ?? false;
 			Year of completion
 			<input
 				type="text"
-				name="artwork-year"
+				name="artwork-completed-year"
 				inputmode="numeric"
 				pattern="[0-9]{1,4}"
 				value="<?= Formatter::EscapeHtml((string)$artwork->CompletedYear) ?>"
@@ -65,7 +65,7 @@ $isEditForm = $isEditForm ?? false;
 		<label>
 			<input
 				type="checkbox"
-				name="artwork-year-is-circa"
+				name="artwork-completed-year-is-circa"
 				<? if($artwork->CompletedYearIsCirca){ ?>checked="checked"<? } ?>
 			/> Year is circa
 		</label>
@@ -172,28 +172,28 @@ $isEditForm = $isEditForm ?? false;
 	</label>
 </fieldset>
 <? if($artwork->CanStatusBeChangedBy($GLOBALS['User'] ?? null) || $artwork->CanEbookUrlBeChangedBy($GLOBALS['User'] ?? null)){ ?>
-<fieldset>
-	<legend>Editor options</legend>
-	<? if($artwork->CanStatusBeChangedBy($GLOBALS['User'] ?? null)){ ?>
-		<label>
-			<span>Artwork approval status</span>
-			<span>
-				<select name="artwork-status">
-					<option value="<?= Enums\ArtworkStatusType::Unverified->value ?>"<? if($artwork->Status == Enums\ArtworkStatusType::Unverified){ ?> selected="selected"<? } ?>>Unverified</option>
-					<option value="<?= Enums\ArtworkStatusType::Declined->value ?>"<? if($artwork->Status == Enums\ArtworkStatusType::Declined){ ?> selected="selected"<? } ?>>Declined</option>
-					<option value="<?= Enums\ArtworkStatusType::Approved->value ?>"<? if($artwork->Status == Enums\ArtworkStatusType::Approved){ ?> selected="selected"<? } ?>>Approved</option>
-				</select>
-			</span>
-		</label>
-	<? } ?>
-	<? if($artwork->CanEbookUrlBeChangedBy($GLOBALS['User'] ?? null)){ ?>
-		<label>
-			<span>In use by</span>
-			<span>The full S.E. ebook URL. If not in use, leave this blank.</span>
-			<input type="url" name="artwork-ebook-url" placeholder="https://standardebooks.org/ebooks/" pattern="^https:\/\/standardebooks\.org\/ebooks/[^\/]+(\/[^\/]+)+$" value="<?= Formatter::EscapeHtml($artwork->EbookUrl) ?>"/>
-		</label>
-	<? } ?>
-</fieldset>
+	<fieldset>
+		<legend>Editor options</legend>
+		<? if($artwork->CanStatusBeChangedBy($GLOBALS['User'] ?? null)){ ?>
+			<label>
+				<span>Artwork approval status</span>
+				<span>
+					<select name="artwork-status">
+						<option value="<?= Enums\ArtworkStatusType::Unverified->value ?>"<? if($artwork->Status == Enums\ArtworkStatusType::Unverified){ ?> selected="selected"<? } ?>>Unverified</option>
+						<option value="<?= Enums\ArtworkStatusType::Declined->value ?>"<? if($artwork->Status == Enums\ArtworkStatusType::Declined){ ?> selected="selected"<? } ?>>Declined</option>
+						<option value="<?= Enums\ArtworkStatusType::Approved->value ?>"<? if($artwork->Status == Enums\ArtworkStatusType::Approved){ ?> selected="selected"<? } ?>>Approved</option>
+					</select>
+				</span>
+			</label>
+		<? } ?>
+		<? if($artwork->CanEbookUrlBeChangedBy($GLOBALS['User'] ?? null)){ ?>
+			<label>
+				<span>In use by</span>
+				<span>The full S.E. ebook URL. If not in use, leave this blank.</span>
+				<input type="url" name="artwork-ebook-url" placeholder="https://standardebooks.org/ebooks/" pattern="^https:\/\/standardebooks\.org\/ebooks/[^\/]+(\/[^\/]+)+$" value="<?= Formatter::EscapeHtml($artwork->EbookUrl) ?>"/>
+			</label>
+		<? } ?>
+	</fieldset>
 <? } ?>
 <div class="footer">
 	<button><? if($isEditForm){ ?>Save changes<? }else{ ?>Submit<? } ?></button>
diff --git a/templates/OpdsNavigationFeed.php b/templates/OpdsNavigationFeed.php
index 2cc453be..18316d54 100644
--- a/templates/OpdsNavigationFeed.php
+++ b/templates/OpdsNavigationFeed.php
@@ -39,7 +39,7 @@ print("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
 		<entry>
 			<title><?= Formatter::EscapeXml($entry->Title) ?></title>
 			<link href="<?= SITE_URL . Formatter::EscapeXml($entry->Url) ?>" rel="<?= Formatter::EscapeXml($entry->Rel) ?>" type="application/atom+xml;profile=opds-catalog;kind=<?= $entry->Type ?>; charset=utf-8"/>
-			<updated><? if($entry->Updated !== null){ ?><?= $entry->Updated->format(Enums\DateTimeFormat::Iso->value) ?><? } ?></updated>
+			<updated><?= $entry->Updated->format(Enums\DateTimeFormat::Iso->value) ?></updated>
 			<id><?= Formatter::EscapeXml($entry->Id) ?></id>
 			<content type="text"><?= Formatter::EscapeXml($entry->Description) ?></content>
 		</entry>
diff --git a/www/artworks/post.php b/www/artworks/post.php
index 4764df2c..b10d6361 100644
--- a/www/artworks/post.php
+++ b/www/artworks/post.php
@@ -19,7 +19,9 @@ try{
 			throw new Exceptions\InvalidPermissionsException();
 		}
 
-		$artwork = Artwork::FromHttpPost();
+		$artwork = new Artwork();
+		$artwork->FillFromHttpPost();
+
 		$artwork->SubmitterUserId = $GLOBALS['User']->UserId ?? null;
 
 		// Only approved reviewers can set the status to anything but unverified when uploading.
@@ -28,7 +30,7 @@ try{
 			throw new Exceptions\InvalidPermissionsException();
 		}
 
-		// If the artwork is approved, set the reviewer
+		// If the artwork is approved, set the reviewer.
 		if($artwork->Status !== Enums\ArtworkStatusType::Unverified){
 			$artwork->ReviewerUserId = $GLOBALS['User']->UserId;
 		}
@@ -56,7 +58,7 @@ try{
 		$artwork->ArtworkId = $originalArtwork->ArtworkId;
 		$artwork->Created = $originalArtwork->Created;
 		$artwork->SubmitterUserId = $originalArtwork->SubmitterUserId;
-		$artwork->Status = $originalArtwork->Status; // Overwrite any value got from POST because we need permission to change the status
+		$artwork->Status = $originalArtwork->Status; // Overwrite any value got from POST because we need permission to change the status.
 
 		$newStatus = Enums\ArtworkStatusType::tryFrom(HttpInput::Str(POST, 'artwork-status') ?? '');
 		if($newStatus !== null){
@@ -96,9 +98,12 @@ try{
 				}
 
 				$artwork->ReviewerUserId = $GLOBALS['User']->UserId;
-			}
 
-			$artwork->Status = $newStatus;
+				$artwork->Status = $newStatus;
+			}
+			else{
+				unset($artwork->Status);
+			}
 		}
 
 		if(isset($_POST['artwork-ebook-url'])){
diff --git a/www/ebooks/ebook.php b/www/ebooks/ebook.php
index eb9893ed..eeb66df7 100644
--- a/www/ebooks/ebook.php
+++ b/www/ebooks/ebook.php
@@ -162,13 +162,7 @@ catch(Exceptions\EbookNotFoundException){
 
 			<?= Template::DonationAlert() ?>
 
-			<? if($ebook->LongDescription === null){ ?>
-				<p>
-					<i>There’s no description for this ebook yet.</i>
-				</p>
-			<? }else{ ?>
-				<?= $ebook->LongDescription ?>
-			<? } ?>
+			<?= $ebook->LongDescription ?>
 		</section>
 
 		<? if($ebook->HasDownloads){ ?>
diff --git a/www/newsletter/subscriptions/post.php b/www/newsletter/subscriptions/post.php
index dd480d8b..a5773e7d 100644
--- a/www/newsletter/subscriptions/post.php
+++ b/www/newsletter/subscriptions/post.php
@@ -30,7 +30,6 @@ try{
 		exit();
 	}
 
-
 	$subscription->User = new User();
 	$subscription->User->Email = HttpInput::Str(POST, 'email');
 	$subscription->IsSubscribedToNewsletter = HttpInput::Bool(POST, 'issubscribedtonewsletter') ?? false;
diff --git a/www/polls/votes/new.php b/www/polls/votes/new.php
index 18f6995a..d90e9085 100644
--- a/www/polls/votes/new.php
+++ b/www/polls/votes/new.php
@@ -17,7 +17,9 @@ try{
 		/** @var PollVote $vote */
 		$vote = $_SESSION['vote'];
 	}
-	else{
+
+	if(!isset($vote->UserId)){
+		$vote->UserId = $GLOBALS['User']->UserId;
 		$vote->User = $GLOBALS['User'];
 	}
 
@@ -59,23 +61,23 @@ catch(Exceptions\PollVoteExistsException $ex){
 		<h1>Vote in the <?= Formatter::EscapeHtml($poll->Name) ?> Poll</h1>
 		<?= Template::Error(['exception' => $exception]) ?>
 		<form method="post" action="<?= Formatter::EscapeHtml($poll->Url) ?>/votes">
-			<input type="hidden" name="email" value="<? if($vote->User !== null){ ?><?= Formatter::EscapeHtml($vote->User->Email) ?><? } ?>" maxlength="80" required="required" />
+			<input type="hidden" name="email" value="<?= Formatter::EscapeHtml($vote->User->Email) ?>" maxlength="80" required="required" />
 			<fieldset>
 				<p>Select one of these options.</p>
 				<ul>
-				<? foreach($poll->PollItems as $pollItem){ ?>
-					<li>
-						<label class="checkbox">
-							<input type="radio" value="<?= $pollItem->PollItemId ?>" name="pollitemid" required="required"<? if($vote->PollItemId == $pollItem->PollItemId){ ?> checked="checked"<? } ?>/>
-							<span>
-								<b><?= $pollItem->Name ?></b>
-							<? if($pollItem->Description !== null){ ?>
-								<span><?= Formatter::EscapeHtml($pollItem->Description) ?></span>
-							<? } ?>
-							</span>
-						</label>
-					</li>
-				<? } ?>
+					<? foreach($poll->PollItems as $pollItem){ ?>
+						<li>
+							<label class="checkbox">
+								<input type="radio" value="<?= $pollItem->PollItemId ?>" name="poll-vote-poll-item-id" required="required"<? if(isset($vote->PollItemId) && $vote->PollItemId == $pollItem->PollItemId){ ?> checked="checked"<? } ?>/>
+								<span>
+									<b><?= $pollItem->Name ?></b>
+									<? if($pollItem->Description !== null){ ?>
+										<span><?= Formatter::EscapeHtml($pollItem->Description) ?></span>
+									<? } ?>
+								</span>
+							</label>
+						</li>
+					<? } ?>
 				</ul>
 			</fieldset>
 			<button>Vote</button>
diff --git a/www/polls/votes/post.php b/www/polls/votes/post.php
index f961bfda..4a9a28bf 100644
--- a/www/polls/votes/post.php
+++ b/www/polls/votes/post.php
@@ -10,7 +10,7 @@ try{
 
 	$vote = new PollVote();
 
-	$vote->PollItemId = HttpInput::Int(POST, 'pollitemid');
+	$vote->FillFromHttpPost();
 
 	$vote->Create(HttpInput::Str(POST, 'email'));