From 7cd6eefe28c567297718f2a4f25e2b3c93f67587 Mon Sep 17 00:00:00 2001
From: Juan Leyva <juanleyvadelgado@gmail.com>
Date: Wed, 2 Mar 2016 11:14:31 +0100
Subject: [PATCH] MDL-53175 file: Allow file_rewrite_pluginfile_urls to reverse

---
 lib/filelib.php            | 10 ++++++++--
 lib/tests/filelib_test.php | 20 ++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/filelib.php b/lib/filelib.php
index 059eb2ca3c3d1..39a7dacaee4d2 100644
--- a/lib/filelib.php
+++ b/lib/filelib.php
@@ -445,6 +445,8 @@ function file_prepare_draft_area(&$draftitemid, $contextid, $component, $fileare
 
 /**
  * Convert encoded URLs in $text from the @@PLUGINFILE@@/... form to an actual URL.
+ * Passing a new option reverse = true in the $options var will make the function to convert actual URLs in $text to encoded URLs
+ * in the @@PLUGINFILE@@ form.
  *
  * @category files
  * @global stdClass $CFG
@@ -454,7 +456,7 @@ function file_prepare_draft_area(&$draftitemid, $contextid, $component, $fileare
  * @param string $component
  * @param string $filearea helps identify the file area.
  * @param int $itemid helps identify the file area.
- * @param array $options text and file options ('forcehttps'=>false)
+ * @param array $options text and file options ('forcehttps'=>false), use reverse = true to reverse the behaviour of the function.
  * @return string the processed text.
  */
 function file_rewrite_pluginfile_urls($text, $file, $contextid, $component, $filearea, $itemid, array $options=null) {
@@ -479,7 +481,11 @@ function file_rewrite_pluginfile_urls($text, $file, $contextid, $component, $fil
         $baseurl = str_replace('http://', 'https://', $baseurl);
     }
 
-    return str_replace('@@PLUGINFILE@@/', $baseurl, $text);
+    if (!empty($options['reverse'])) {
+        return str_replace($baseurl, '@@PLUGINFILE@@/', $text);
+    } else {
+        return str_replace('@@PLUGINFILE@@/', $baseurl, $text);
+    }
 }
 
 /**
diff --git a/lib/tests/filelib_test.php b/lib/tests/filelib_test.php
index 555a45cb235de..78854dd887d8c 100644
--- a/lib/tests/filelib_test.php
+++ b/lib/tests/filelib_test.php
@@ -951,6 +951,26 @@ public function test_curl_useragent() {
         $this->assertSame(0, $extcurl->get_errno());
         $this->assertSame('', $contents);
     }
+
+    /**
+     * Test file_rewrite_pluginfile_urls.
+     */
+    public function test_file_rewrite_pluginfile_urls() {
+
+        $syscontext = context_system::instance();
+        $originaltext = 'Fake test with an image <img src="@@PLUGINFILE@@/image.png">';
+
+        // Do the rewrite.
+        $finaltext = file_rewrite_pluginfile_urls($originaltext, 'pluginfile.php', $syscontext->id, 'user', 'private', 0);
+        $this->assertContains("pluginfile.php", $finaltext);
+
+        // Now undo.
+        $options = array('reverse' => true);
+        $finaltext = file_rewrite_pluginfile_urls($finaltext, 'pluginfile.php', $syscontext->id, 'user', 'private', 0, $options);
+
+        // Compare the final text is the same that the original.
+        $this->assertEquals($originaltext, $finaltext);
+    }
 }
 
 /**