Add a Default EbookSortType

This allows the user to run a keyword search and then change the sort
order. `Default` is interpreted as `Relevance` if a query is present,
`Newest` if not.

lib/Ebook.php

@@ -2444,6 +2444,15 @@ final class Ebook{
 				break;
 		}
 
+		if($sort === null || $sort == Enums\EbookSortType::Default){
+			if($query !== null && $query != ''){
+				$sort = Enums\EbookSortType::Relevance;
+			}
+			else{
+				$sort = Enums\EbookSortType::Newest;
+			}
+		}
+
 		$orderBy = 'e.EbookCreated desc';
 		if($sort == Enums\EbookSortType::AuthorAlpha){
 			$joinContributors = 'inner join Contributors con using (EbookId)';
@@ -2471,7 +2480,7 @@ final class Ebook{
 			$whereCondition .= ' and match(e.IndexableText, e.Title, e.IndexableAuthors, e.IndexableCollections) against(?) ';
 			$params[] = $query;
 
-			if($sort == null || $sort == Enums\EbookSortType::Relevance || $sort == Enums\EbookSortType::Newest){
+			if($sort == Enums\EbookSortType::Relevance){
 				$orderBy = '(
 						match(e.Title) against (?) * ' . EBOOK_SEARCH_WEIGHT_TITLE . ' +
 						match(e.IndexableAuthors) against (?) * ' . EBOOK_SEARCH_WEIGHT_AUTHORS . ' +

lib/Enums/EbookSortType.php

@@ -7,4 +7,5 @@ enum EbookSortType: string{
 	case ReadingEase = 'reading-ease';
 	case Length = 'length';
 	case Relevance = 'relevance';
+	case Default = 'default'; // Interpreted as `Relevance` if a query is present, `Newest` if not.
 }

templates/SearchForm.php

@@ -26,8 +26,9 @@ $isAllSelected = sizeof($tags) == 0 || in_array('all', $tags);
 			<select name="sort">
 				<? if(isset($query) && $query != ''){ ?>
 					<option value="<?= Enums\EbookSortType::Relevance->value ?>"<? if($sort == Enums\EbookSortType::Relevance){ ?> selected="selected"<? } ?>>Relevance</option>
-				<? }else{ ?>
 					<option value="<?= Enums\EbookSortType::Newest->value ?>"<? if($sort == Enums\EbookSortType::Newest){ ?> selected="selected"<? } ?>>S.E. release date (new &#x2192; old)</option>
+				<? }else{ ?>
+					<option value="<?= Enums\EbookSortType::Default->value ?>"<? if($sort == Enums\EbookSortType::Newest){ ?> selected="selected"<? } ?>>S.E. release date (new &#x2192; old)</option>
 				<? } ?>
 				<option value="<?= Enums\EbookSortType::AuthorAlpha->value ?>"<? if($sort == Enums\EbookSortType::AuthorAlpha){ ?> selected="selected"<? } ?>>Author name  (a &#x2192; z)</option>
 				<option value="<?= Enums\EbookSortType::ReadingEase->value ?>"<? if($sort == Enums\EbookSortType::ReadingEase){ ?> selected="selected"<? } ?>>Reading ease (easy &#x2192; hard)</option>

www/ebooks/index.php

@@ -23,20 +23,27 @@ try{
 		$perPage = EBOOKS_PER_PAGE;
 	}
 
+	if($sort == Enums\EbookSortType::Default){
+		if($query != ''){
+			$sort = Enums\EbookSortType::Relevance;
+		}
+		else{
+			$sort = Enums\EbookSortType::Newest;
+		}
+	}
+
+	// Malformed query: Can't sort by `Relevance` if `$query` is empty.
+	// This could happen if the user was looking at `Relevance` results, then deleted the query and hit the Filter button.
+	if($sort == Enums\EbookSortType::Relevance && $query == ''){
+		$sort = Enums\EbookSortType::Newest;
+	}
+
 	// If we're passed string values that are the same as the defaults, set them to null so that we can have cleaner query strings in the navigation footer.
 	if($view === Enums\ViewType::Grid){
 		$view = null;
 	}
 
-	if($query != ''){
+	if(($sort == Enums\EbookSortType::Newest && $query == '') || ($sort == Enums\EbookSortType::Relevance && $query != '')){
-		$queryStringParams['query'] = $query;
-		// If the user entered a query with the default sort order, change it to relevance sort.
-		if($sort == Enums\EbookSortType::Newest){
-			$sort = Enums\EbookSortType::Relevance;
-		}
-	}
-
-	if($sort == Enums\EbookSortType::Newest){
 		$sort = null;
 	}
 
@@ -46,6 +53,10 @@ try{
 
 	$pageDescription = 'Page ' . $page . ' of the Standard Ebooks free ebook library';
 
+	if($query != ''){
+		$queryStringParams['query'] = $query;
+	}
+
 	if(sizeof($tags) > 0){
 		$queryStringParams['tags'] = $tags;
 	}