ENHANCEMENT Added File::get_class_for_file_extension() instead of hardcoding it in Folder->constructChild(). Allows for custom classes in files uploaded through core functionality like the Upload and FileField logic.

filesystem/File.php

@@ -790,6 +790,53 @@ class File extends DataObject {
 		return $fields;
 	}
 	
-}
+	/**
+	 * @var Array Only use lowercase extensions in here.
+	 */
+	static $class_for_file_extension = array(
+		'*' => 'File',
+		'jpg' => 'Image',
+		'jpeg' => 'Image',
+		'png' => 'Image',
+		'gif' => 'Image',
+	);
 
-?>
+	/**
+	 * Maps a {@link File} subclass to a specific extension.
+	 * By default, files with common image extensions will be created
+	 * as {@link Image} instead of {@link File} when using 
+	 * {@link Folder::constructChild}, {@link Folder::addUploadToFolder}),
+	 * and the {@link Upload} class (either directly or through {@link FileField}).
+	 * For manually instanciated files please use this mapping getter.
+	 * 
+	 * Caution: Changes to mapping doesn't apply to existing file records in the database.
+	 * Also doesn't hook into {@link Object::getCustomClass()}.
+	 * 
+	 * @param String File extension, without dot prefix. Use an asterisk ('*')
+	 * to specify a generic fallback if no mapping is found for an extension.
+	 * @return String Classname for a subclass of {@link File}
+	 */
+	static function get_class_for_file_extension($ext) {
+		$map = array_change_key_case(self::$class_for_file_extension, CASE_LOWER);
+		return (array_key_exists(strtolower($ext), $map)) ? $map[strtolower($ext)] : $map['*'];
+	}
+	
+	/**
+	 * See {@link get_class_for_file_extension()}.
+	 * 
+	 * @param String|array
+	 * @param String
+	 */
+	static function set_class_for_file_extension($exts, $class) {
+		if(!is_array($exts)) $exts = array($exts);
+		foreach($exts as $ext) {
+			if(ClassInfo::is_subclass_of($ext, 'File')) {
+				throw new InvalidArgumentException(
+					sprintf('Class "%s" (for extension "%s") is not a valid subclass of File', $class, $ext)
+				);
+			}
+			self::$class_for_file_extension[$ext] = $class;
+		}
+	}
+	
+}

filesystem/Folder.php

@@ -183,12 +183,7 @@ class Folder extends File {
 		if(is_dir($baseDir . $name)) {
 			$className = "Folder";
 		} else {
-			// Could use getimagesize to get the type of the image
-			$ext = strtolower(substr($name,strrpos($name,'.')+1));
-			switch($ext) {
-				case "gif": case "jpg": case "jpeg": case "png": $className = "Image"; break;
-				default: $className = "File";
-			}
+			$className = File::get_class_for_file_extension(pathinfo($name, PATHINFO_EXTENSION));
 		}
 
 		if(Member::currentUser()) $ownerID = Member::currentUser()->ID;

filesystem/Upload.php

@@ -98,7 +98,10 @@ class Upload extends Controller {
 		
 		if(!$folderPath) $folderPath = self::$uploads_folder;
 		
-		if(!$this->file) $this->file = new File();
+		if(!$this->file) {
+			$fileClass = File::get_class_for_file_extension(pathinfo($tmpFile['name'], PATHINFO_EXTENSION));
+			$this->file = new $fileClass();
+		}
 		
 		if(!is_array($tmpFile)) {
 			user_error("Upload::load() Not passed an array.  Most likely, the form hasn't got the right enctype", E_USER_ERROR);

forms/FileField.php

@@ -133,14 +133,15 @@ class FileField extends FormField {
 	
 	public function saveInto(DataObject $record) {
 		if(!isset($_FILES[$this->name])) return false;
+		$fileClass = File::get_class_for_file_extension(pathinfo($_FILES[$this->name]['name'], PATHINFO_EXTENSION));
 		
 		if($this->relationAutoSetting) {
 			// assume that the file is connected via a has-one
 			$hasOnes = $record->has_one($this->name);
 			// try to create a file matching the relation
-			$file = (is_string($hasOnes)) ? Object::create($hasOnes) : new File(); 
+			$file = (is_string($hasOnes)) ? Object::create($hasOnes) : new $fileClass(); 
 		} else {
-			$file = new File();
+			$file = new $fileClass();
 		}
 		
 		$this->upload->loadIntoFile($_FILES[$this->name], $file, $this->folderName);

tests/filesystem/FileTest.php

@@ -7,6 +7,8 @@ class FileTest extends SapphireTest {
 	
 	static $fixture_file = 'FileTest.yml';
 	
+	protected $extraDataObjects = array('FileTest_MyCustomFile');
+	
 	function testCreateWithFilenameWithSubfolder() {
 		// Note: We can't use fixtures/setUp() for this, as we want to create the db record manually.
 		// Creating the folder is necessary to avoid having "Filename" overwritten by setName()/setRelativePath(),
@@ -257,6 +259,43 @@ class FileTest extends SapphireTest {
 		$this->assertEquals($folder->Title, $newTitle3, "Folder Title updated after rename of Filename");
 	}
 
+	
+	function testGetClassForFileExtension() {
+		$orig = File::$class_for_file_extension;
+		File::$class_for_file_extension['*'] = 'MyGenericFileClass';
+		File::$class_for_file_extension['foo'] = 'MyFooFileClass';
+
+		$this->assertEquals(
+			'MyFooFileClass',
+			File::get_class_for_file_extension('foo'),
+			'Finds directly mapped file classes'
+		);
+		$this->assertEquals(
+			'MyFooFileClass',
+			File::get_class_for_file_extension('FOO'),
+			'Works without case sensitivity'
+		);
+		$this->assertEquals(
+			'MyGenericFileClass',
+			File::get_class_for_file_extension('unknown'),
+			'Falls back to generic class for unknown extensions'
+		);
+		
+		File::$class_for_file_extension = $orig;
+	}
+	
+	function testFolderConstructChild() {
+		$orig = File::$class_for_file_extension;
+		File::$class_for_file_extension['gif'] = 'FileTest_MyCustomFile';
+		
+		$folder1 = $this->objFromFixture('Folder', 'folder1');
+		$fileID = $folder1->constructChild('myfile.gif');
+		$file = DataObject::get_by_id('File', $fileID);
+		$this->assertEquals('FileTest_MyCustomFile', get_class($file));
+		
+		File::$class_for_file_extension = $orig;
+	}
+		
 	/////////////////////////////////////////////////////////////////////////////////////////////////////////////
 	
 	function setUp() {
@@ -309,3 +348,7 @@ class FileTest extends SapphireTest {
 	}
 
 }
+
+class FileTest_MyCustomFile extends File implements TestOnly {
+	
+}