From: rillke <rainerrillke@hotmail.com>
Date: Sat, 21 Jun 2014 12:00:55 +0000 (+0200)
Subject: Allow third party code to hook-up MIME type detection
X-Git-Tag: 1.31.0-rc.0~15028^2
X-Git-Url: http://git.cyclocoop.org/%22.%24h.%22?a=commitdiff_plain;h=bd7750cee45c0c8a185edb43b9c7a0a1ccbcb3e9;p=lhc%2Fweb%2Fwiklou.git

Allow third party code to hook-up MIME type detection

Adding 3 hooks to MimeMagic.php

- MimeMagicInit: Add assignments of MIME types -> Media types
  and assignments of MIME types -> File extensions
- MimeMagicImproveFromExtension: Further improve the MIME type detected
  by considering the file extension
- MimeMagicGuessFromContent: Guess the MIME from file content

This is the successor of Icf9eec10bec7c0a7e.

PHP's own module fileinfo module is not capable detecting Chemical
table files. Instead, they are reported as text/plain.

MediaHandlers can be attached by MIME type only. That's why these
changes are required for [[Extension:MolHandler]] to work.

Clean up:
Do not create unused property MimeMagic::mToMime.

Change-Id: I67f3e4e83b47e6df0d9e8371f09a741a8aa77651
---

diff --git a/docs/hooks.txt b/docs/hooks.txt
index b1ef47ca0d..7cbb5d1855 100644
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -1757,6 +1757,30 @@ caches.
 $title: name of the page changed.
 $text: new contents of the page.
 
+'MimeMagicInit': Before processing the list mapping MIME types to media types
+and the list mapping MIME types to file extensions.
+As an extension author, you are encouraged to submit patches to MediaWiki's
+core to add new MIME types to mime.types.
+$mimeMagic: Instance of MimeMagic.
+  Use $mimeMagic->addExtraInfo( $stringOfInfo );
+  for adding new MIME info to the list.
+  Use $mimeMagic->addExtraTypes( $stringOfTypes );
+  for adding new MIME types to the list.
+
+'MimeMagicImproveFromExtension': Allows MW extensions to further improve the
+MIME type detected by considering the file extension.
+$mimeMagic: Instance of MimeMagic.
+$ext: File extension.
+&$mime: MIME type (in/out).
+
+'MimeMagicGuessFromContent': Allows MW extensions guess the MIME by content.
+$mimeMagic: Instance of MimeMagic.
+&$head: First 1024 bytes of the file in a string (in - Do not alter!).
+&$tail: More or equal than last 65558 bytes of the file in a string
+  (in - Do not alter!).
+$file: File path.
+&$mime: MIME type (out).
+
 'ModifyExportQuery': Modify the query used by the exporter.
 $db: The database object to be queried.
 &$tables: Tables in the query.
diff --git a/includes/MimeMagic.php b/includes/MimeMagic.php
index 59f850c565..b4d3ab1c1e 100644
--- a/includes/MimeMagic.php
+++ b/includes/MimeMagic.php
@@ -164,6 +164,14 @@ class MimeMagic {
 	 */
 	protected $mIEAnalyzer;
 
+	/** @var string Extra MIME types, set for example by media handling extensions
+	 */
+	private $mExtraTypes = '';
+
+	/** @var string Extra MIME info, set for example by media handling extensions
+	 */
+	private $mExtraInfo = '';
+
 	/** @var MimeMagic The singleton instance
 	 */
 	private static $instance = null;
@@ -179,6 +187,9 @@ class MimeMagic {
 
 		global $wgMimeTypeFile, $IP;
 
+		# Allow media handling extensions adding MIME-types and MIME-info
+		wfRunHooks( 'MimeMagicInit', array( $this ) );
+
 		$types = MM_WELL_KNOWN_MIME_TYPES;
 
 		if ( $wgMimeTypeFile == 'includes/mime.types' ) {
@@ -197,11 +208,13 @@ class MimeMagic {
 			wfDebug( __METHOD__ . ": no mime types file defined, using build-ins only.\n" );
 		}
 
+		$types .= "\n" . $this->mExtraTypes;
+
 		$types = str_replace( array( "\r\n", "\n\r", "\n\n", "\r\r", "\r" ), "\n", $types );
 		$types = str_replace( "\t", " ", $types );
 
 		$this->mMimeToExt = array();
-		$this->mToMime = array();
+		$this->mExtToMime = array();
 
 		$lines = explode( "\n", $types );
 		foreach ( $lines as $s ) {
@@ -272,6 +285,8 @@ class MimeMagic {
 			wfDebug( __METHOD__ . ": no mime info file defined, using build-ins only.\n" );
 		}
 
+		$info .= "\n" . $this->mExtraInfo;
+
 		$info = str_replace( array( "\r\n", "\n\r", "\n\n", "\r\r", "\r" ), "\n", $info );
 		$info = str_replace( "\t", " ", $info );
 
@@ -342,6 +357,26 @@ class MimeMagic {
 		return self::$instance;
 	}
 
+	/**
+	 * Adds to the list mapping MIME to file extensions.
+	 * As an extension author, you are encouraged to submit patches to
+	 * MediaWiki's core to add new MIME types to mime.types.
+	 * @param string $types
+	 */
+	public function addExtraTypes( $types ) {
+		$this->mExtraTypes .= "\n" . $types;
+	}
+
+	/**
+	 * Adds to the list mapping MIME to media type.
+	 * As an extension author, you are encouraged to submit patches to
+	 * MediaWiki's core to add new MIME info to mime.info.
+	 * @param string $info
+	 */
+	public function addExtraInfo( $info ) {
+		$this->mExtraInfo .= "\n" . $info;
+	}
+
 	/**
 	 * Returns a list of file extensions for a given mime type as a space
 	 * separated string or null if the mime type was unrecognized. Resolves
@@ -518,6 +553,9 @@ class MimeMagic {
 			$mime = $this->guessTypesForExtension( $ext );
 		}
 
+		# Media handling extensions can improve the MIME detected
+		wfRunHooks( 'MimeMagicImproveFromExtension', array( $this, $ext, &$mime ) );
+
 		if ( isset( $this->mMimeTypeAliases[$mime] ) ) {
 			$mime = $this->mMimeTypeAliases[$mime];
 		}
@@ -744,7 +782,17 @@ class MimeMagic {
 			return 'image/vnd.djvu';
 		}
 
-		return false;
+		# Media handling extensions can guess the MIME by content
+		# It's intentionally here so that if core is wrong about a type (false positive),
+		# people will hopefully nag and submit patches :)
+		$mime = false;
+		# Some strings by reference for performance - assuming well-behaved hooks
+		wfRunHooks(
+			'MimeMagicGuessFromContent',
+			array( $this, &$head, &$tail, $file, &$mime )
+		);
+
+		return $mime;
 	}
 
 	/**