Add a configuration switch for enabled preview mimetypes

Backport of https://github.com/owncloud/core/pull/11211 to stable7

1 files changed, 30 insertions, 7 deletions

diff --git a/lib/private/preview.php b/lib/private/preview.php
index 9006a2e8cbe..40b3eb8d44b 100755
--- a/lib/private/preview.php
+++ b/lib/private/preview.php
@@ -21,7 +21,6 @@ require_once 'preview/mp3.php';
 require_once 'preview/pdf.php';
 require_once 'preview/svg.php';
 require_once 'preview/txt.php';
-require_once 'preview/unknown.php';
 require_once 'preview/office.php';
 
 class Preview {
@@ -59,6 +58,7 @@ class Preview {
 	//preview providers
 	static private $providers = array();
 	static private $registeredProviders = array();
+	static private $enabledProviders = array();
 
 	/**
 	 * @var \OCP\Files\FileInfo
@@ -665,7 +665,33 @@ class Preview {
 	 * @return void
 	 */
 	public static function registerProvider($class, $options = array()) {
-		self::$registeredProviders[] = array('class' => $class, 'options' => $options);
+		/**
+		* Only register providers that have been explicitly enabled
+		*
+		* The following providers are enabled by default:
+		*  - OC\Preview\Image
+		*  - OC\Preview\MP3
+		*  - OC\Preview\TXT
+		*  - OC\Preview\MarkDown
+		*
+		* The following providers are disabled by default due to performance or privacy concerns:
+		*  - OC\Preview\Office
+		*  - OC\Preview\SVG
+		*  - OC\Preview\Movies
+		*  - OC\Preview\PDF
+		*/
+		if(empty(self::$enabledProviders)) {
+				self::$enabledProviders = \OC_Config::getValue('enabledPreviewProviders', array(
+						'OC\Preview\Image',
+						'OC\Preview\MP3',
+						'OC\Preview\TXT',
+						'OC\Preview\MarkDown',
+					));
+			}
+
+		if(in_array($class, self::$enabledProviders)) {
+			self::$registeredProviders[] = array('class' => $class, 'options' => $options);
+		}
 	}
 
 	/**
@@ -674,8 +700,7 @@ class Preview {
 	 */
 	private static function initProviders() {
 		if (!\OC_Config::getValue('enable_previews', true)) {
-			$provider = new Preview\Unknown(array());
-			self::$providers = array($provider->getMimeType() => $provider);
+			self::$providers = array();
 			return;
 		}
 
@@ -747,9 +772,7 @@ class Preview {
 			self::initProviders();
 		}
 
-		//remove last element because it has the mimetype *
-		$providers = array_slice(self::$providers, 0, -1);
-		foreach ($providers as $supportedMimeType => $provider) {
+		foreach (self::$providers as $supportedMimeType => $provider) {
 			if (preg_match($supportedMimeType, $mimeType)) {
 				return true;
 			}