MDL-42995 libraries: Global function to strip pluginfile content

diff --git a/lib/tests/weblib_test.php b/lib/tests/weblib_test.php
index 8718534..1cdd34b 100644 (file)
--- a/lib/tests/weblib_test.php
+++ b/lib/tests/weblib_test.php
@@ -492,4 +492,43 @@ class core_weblib_testcase extends advanced_testcase {
         $this->assertEquals(DEBUG_NONE, $CFG->debug);
         $this->assertFalse($CFG->debugdeveloper);
     }
+
+    public function test_strip_pluginfile_content() {
+        $source = <<<SOURCE
+Hello!
+
+I'm writing to you from the Moodle Majlis in Muscat, Oman, where we just had several days of Moodle community goodness.
+
+URL outside a tag: https://moodle.org/logo/logo-240x60.gif
+Plugin url outside a tag: @@PLUGINFILE@@/logo-240x60.gif
+
+External link 1:<img src='https://moodle.org/logo/logo-240x60.gif' alt='Moodle'/>
+External link 2:<img alt="Moodle" src="https://moodle.org/logo/logo-240x60.gif"/>
+Internal link 1:<img src='@@PLUGINFILE@@/logo-240x60.gif' alt='Moodle'/>
+Internal link 2:<img alt="Moodle" src="@@PLUGINFILE@@logo-240x60.gif"/>
+Anchor link 1:<a href="@@PLUGINFILE@@logo-240x60.gif" alt="bananas">Link text</a>
+Anchor link 2:<a title="bananas" href="../logo-240x60.gif">Link text</a>
+Anchor + ext. img:<a title="bananas" href="../logo-240x60.gif"><img alt="Moodle" src="@@PLUGINFILE@@logo-240x60.gif"/></a>
+Ext. anchor + img:<a href="@@PLUGINFILE@@logo-240x60.gif"><img alt="Moodle" src="https://moodle.org/logo/logo-240x60.gif"/></a>
+SOURCE;
+        $expected = <<<EXPECTED
+Hello!
+
+I'm writing to you from the Moodle Majlis in Muscat, Oman, where we just had several days of Moodle community goodness.
+
+URL outside a tag: https://moodle.org/logo/logo-240x60.gif
+Plugin url outside a tag: @@PLUGINFILE@@/logo-240x60.gif
+
+External link 1:<img src="https://moodle.org/logo/logo-240x60.gif" alt="Moodle" />
+External link 2:<img alt="Moodle" src="https://moodle.org/logo/logo-240x60.gif" />
+Internal link 1:
+Internal link 2:
+Anchor link 1:Link text
+Anchor link 2:<a title="bananas" href="../logo-240x60.gif">Link text</a>
+Anchor + ext. img:<a title="bananas" href="../logo-240x60.gif"></a>
+Ext. anchor + img:<img alt="Moodle" src="https://moodle.org/logo/logo-240x60.gif" />
+EXPECTED;
+        $this->assertSame($expected, strip_pluginfile_content($source));
+    }
+
 }

diff --git a/lib/weblib.php b/lib/weblib.php
index 955526e..4c4499c 100644 (file)
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -1523,6 +1523,25 @@ function format_module_intro($module, $activity, $cmid, $filter=true) {
     return trim(format_text($intro, $activity->introformat, $options, null));
 }
 
+/**
+ * Removes the usage of Moodle files from a text.
+ *
+ * In some rare cases we need to re-use a text that already has embedded links
+ * to some files hosted within Moodle. But the new area in which we will push
+ * this content does not support files... therefore we need to remove those files.
+ *
+ * @param string $source The text
+ * @return string The stripped text
+ */
+function strip_pluginfile_content($source) {
+    $baseurl = '@@PLUGINFILE@@';
+    // Looking for something like < .* "@@pluginfile@@.*" .* >
+    $pattern = '$<[^<>]+["\']' . $baseurl . '[^"\']*["\'][^<>]*>$';
+    $stripped = preg_replace($pattern, '', $source);
+    // Use purify html to rebalence potentially mismatched tags and generally cleanup.
+    return purify_html($stripped);
+}
+
 /**
  * Legacy function, used for cleaning of old forum and glossary text only.
  *