Add newsletter management functionality

lib/Exceptions/ValidationException.php

@@ -0,0 +1,63 @@
+<?
+namespace Exceptions;
+
+use function Safe\json_encode;
+
+class ValidationException extends SeException{
+	public $Exceptions = [];
+	public $HasExceptions = false;
+	public $IsFatal = false;
+
+	public function __toString(): string{
+		$output = '';
+		foreach($this->Exceptions as $exception){
+			$output .= $exception->getMessage() . '; ';
+		}
+
+		return rtrim($output, '; ');
+	}
+
+	public function Add(\Exception $exception, bool $isFatal = false): void{
+		if(is_a($exception, static::class)){
+			foreach($exception->Exceptions as $childException){
+				$this->Add($childException);
+			}
+		}
+		else{
+			$this->Exceptions[] = $exception;
+		}
+
+		if($isFatal){
+			$this->IsFatal = true;
+		}
+
+		$this->HasExceptions = true;
+	}
+
+	public function Serialize(): string{
+		$val = '';
+		foreach($this->Exceptions as $childException){
+			$val .= $childException->getCode() . ',';
+		}
+
+		$val = rtrim($val, ',');
+
+		return $val;
+	}
+
+	public function Has(string $exception): bool{
+		foreach($this->Exceptions as $childException){
+			if(is_a($childException, $exception)){
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	public function Clear(): void{
+		unset($this->Exceptions);
+		$this->Exceptions = [];
+		$this->HasExceptions = false;
+	}
+}