♻️ improve content file listing

src/newsletter.php

@@ -363,13 +363,11 @@
 		
 		
 		/**
-		* HELPER: Read one content file.
+		* HELPER: List all available content files.
 		* 
-		* @param string $name		Name of the content file to read.
-		* 
-		* @return array				Content file data.
+		* @return array		List of content file names.
 		*/
-		private static function content_file_read(string $name): array {
+		private static function content_file_list(): array {
 			// GET AVAILABLE CONTENT FILES //
 			$indir = scandir("./newsletter/content");
 			$content_file_list = [];
@@ -379,13 +377,51 @@
 				$path = "./newsletter/content/" . $one_element;
 				if(!is_file($path)) continue;
 				
-				// check extension
-				if(substr($one_element, strlen($one_element) - strlen(".data.php")) !== ".data.php") continue;
+				// check file name format
+				if(!preg_match("/\d{4}-\d{2}-\d{2}(-[a-z0-9]+)+\.data\.php/", $one_element)) continue;
 				
 				// add to list
 				$content_file_list[] = $one_element;
 			}
 			
+			// return list
+			return $content_file_list;
+		}
+		
+		
+		
+		/**
+		* HELPER: List all available content names.
+		* 
+		* @return array		List of content names.
+		*/
+		public static function content_list(): array {
+			// get available content files
+			$content_file_list = self::content_file_list();
+			
+			// remove file extension
+			$content_name_list = [];
+			foreach($content_file_list as $one_content_file){
+				$content_name_list[] = substr($one_content_file, 0, strlen($one_content_file) - strlen(".data.php"));
+			}
+			
+			// return list
+			return $content_name_list;
+		}
+		
+		
+		
+		/**
+		* HELPER: Read one content file.
+		* 
+		* @param string $name		Name of the content file to read.
+		* 
+		* @return array				Content file data.
+		*/
+		private static function content_file_read(string $name): array {
+			// GET AVAILABLE CONTENT FILES //
+			$content_file_list = self::content_file_list();
+			
 			
 			// PARSE FILE //
 			// build content file name