From 885d4817499f49328160b0e699b9fa00da6dfc74 Mon Sep 17 00:00:00 2001
From: Amaia Anabitarte <amaia@moodle.com>
Date: Thu, 23 Jan 2020 13:05:47 +0100
Subject: [PATCH] MDL-67337 filter_displayh5p: Apply filter inside <a> tags

---
 filter/displayh5p/filter.php                  | 34 ++++++++++++++++---
 .../displayh5p/tests/behat/h5p_filter.feature | 16 +++++++--
 filter/displayh5p/tests/filter_test.php       | 18 ++++++----
 3 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/filter/displayh5p/filter.php b/filter/displayh5p/filter.php
index 9e2bae7d174..61360950ae3 100644
--- a/filter/displayh5p/filter.php
+++ b/filter/displayh5p/filter.php
@@ -74,6 +74,7 @@ class filter_displayh5p extends moodle_text_filter {
         $specialchars = ['?', '&'];
         $escapedspecialchars = ['\?', '&amp;'];
         $h5pcontents = array();
+        $h5plinks = array();
 
         // Check all allowed sources.
         foreach ($allowedsources as $source) {
@@ -82,7 +83,8 @@ class filter_displayh5p extends moodle_text_filter {
 
             if (($source == $localsource)) {
                 $params['tagbegin'] = '<iframe src="'.$CFG->wwwroot.'/h5p/embed.php?url=';
-                $ultimatepattern = '#'.$source.'#';
+                $escapechars = $source;
+                $ultimatepattern = $source;
             } else {
                 if (!stripos($source, 'embed')) {
                     $params['urlmodifier'] = '/embed';
@@ -90,7 +92,7 @@ class filter_displayh5p extends moodle_text_filter {
                 // Convert special chars.
                 $sourceid = str_replace('[id]', '[0-9]+', $source);
                 $escapechars = str_replace($specialchars, $escapedspecialchars, $sourceid);
-                $ultimatepattern = '#(' . $escapechars . ')#';
+                $ultimatepattern = '(' . $escapechars . ')';
             }
 
             // Improve performance creating filterobjects only when needed.
@@ -101,15 +103,39 @@ class filter_displayh5p extends moodle_text_filter {
             $h5pcontenturl = new filterobject($source, null, null, false,
                 false, null, [$this, 'filterobject_prepare_replacement_callback'], $params);
 
-            $h5pcontenturl->workregexp = $ultimatepattern;
+            $h5pcontenturl->workregexp = '#'.$ultimatepattern.'#';
             $h5pcontents[] = $h5pcontenturl;
+
+            // Regex to find h5p extensions in an <a> tag.
+            $linkregexp = '~<a [^>]*href=["\']('.$escapechars.'[^"\']*)["\'][^>]*>([^<]*)</a>~is';
+
+            $h5plinkurl = new filterobject($linkregexp, null, null, false,
+                false, null, [$this, 'filterobject_prepare_replacement_callback'], $params);
+            $h5plinkurl->workregexp = $linkregexp;
+            $h5plinks[] = $h5plinkurl;
         }
 
-        if (empty($h5pcontents)) {
+        if (empty($h5pcontents) && empty($h5links)) {
             // No matches to deal with.
             return $text;
         }
 
+        // Apply filter inside <a> tag href attribute.
+        // We can not use filter_phrase function because it removes all tags and can not be applied in tag attributes.
+        foreach ($h5plinks as $h5plink) {
+            $text = preg_replace_callback($h5plink->workregexp,
+                function ($matches) use ($h5plink) {
+                    if ($matches[1] == $matches[2]) {
+                        filter_prepare_phrase_for_replacement($h5plink);
+
+                        return str_replace('$1', $matches[1], $h5plink->workreplacementphrase);
+                    } else {
+                        return $matches[0];
+                    }
+                }, $text);
+
+        }
+
         $result = filter_phrases($text, $h5pcontents, null, null, false, true);
 
         // Encoding H5P file URLs.
diff --git a/filter/displayh5p/tests/behat/h5p_filter.feature b/filter/displayh5p/tests/behat/h5p_filter.feature
index ff62186664f..4bad0907e61 100644
--- a/filter/displayh5p/tests/behat/h5p_filter.feature
+++ b/filter/displayh5p/tests/behat/h5p_filter.feature
@@ -35,13 +35,25 @@ Feature: Render H5P content using filters
     Then I should see "Lorum ipsum"
 
   @javascript
-  Scenario: Add an external H5P content URL in a link. Shouldn't be rendered.
+  Scenario: Add an external H5P content URL in a link with the URL. Should be rendered.
     Given I log in as "teacher1"
     And I am on "Course 1" course homepage
     And I follow "PageName1"
     And I navigate to "Edit settings" in current page administration
 #   This content won't be displayed, so this scenario shouldn't be labeled as external.
-    And I set the field "Page content" to "<a href='https://moodle.h5p.com/content/1290772960722742119/embed'>Go to https://moodle.h5p.com/content/1290772960722742119/embed</a>"
+    And I set the field "Page content" to "<a href='https://moodle.h5p.com/content/1290772960722742119/embed'>https://moodle.h5p.com/content/1290772960722742119/embed</a>"
+    When I click on "Save and display" "button"
+    And I wait until the page is ready
+    And I switch to "h5p-iframe" class iframe
+    Then I should see "Lorum ipsum"
+
+  Scenario: Add an external H5P content URL in a link with text. Shouldn't be rendered.
+    Given I log in as "teacher1"
+    And I am on "Course 1" course homepage
+    And I follow "PageName1"
+    And I navigate to "Edit settings" in current page administration
+#   This content won't be displayed, so this scenario shouldn't be labeled as external.
+    And I set the field "Page content" to "<a href='https://moodle.h5p.com/content/1290772960722742119/embed'>Here you are the content</a>"
     When I click on "Save and display" "button"
     And I wait until the page is ready
     Then ".h5p-iframe" "css_element" should not exist
diff --git a/filter/displayh5p/tests/filter_test.php b/filter/displayh5p/tests/filter_test.php
index 8ace0931a14..467118cea2c 100644
--- a/filter/displayh5p/tests/filter_test.php
+++ b/filter/displayh5p/tests/filter_test.php
@@ -42,7 +42,7 @@ class filter_displayh5p_testcase extends advanced_testcase {
         $this->resetAfterTest(true);
 
         set_config('allowedsources',
-            "https://h5p.org/h5p/embed/[id]\nhttps://moodle.h5p.com/content/[id]/embed\nhttps://moodle.h5p.com/content/[id]
+            "https://moodle.h5p.com/content/[id]/embed\nhttps://moodle.h5p.com/content/[id]
                 \nhttps://generic.wordpress.soton.ac.uk/altc/wp-admin/admin-ajax.php?action=h5p_embed&id=[id]",
             'filter_displayh5p');
     }
@@ -74,16 +74,20 @@ class filter_displayh5p_testcase extends advanced_testcase {
         return [
             ["http:://example.com", "#http:://example.com#"],
             ["http://google.es/h5p/embed/3425234", "#http://google.es/h5p/embed/3425234#"],
-            ["https://h5p.org/h5p/embed/547225", "#<iframe src=\"https://h5p.org/h5p/embed/547225\"[^>]+?>#"],
             ["https://moodle.h5p.com/content/1290729733828858779/embed", "#<iframe src=\"https://moodle.h5p.com/content/1290729733828858779/embed\"[^>]+?>#"],
             ["https://moodle.h5p.com/content/1290729733828858779", "#<iframe src=\"https://moodle.h5p.com/content/1290729733828858779/embed\"[^>]+?>#"],
-            ["<a href=\"https://h5p.org/h5p/embed/547225\">link</a>",  "#^((?!iframe).)*$#"],
-            ["this is a text with an h5p url https://h5p.org/h5p/embed/547225 inside",
-                    "#this is a text with an h5p url <iframe src=\"https://h5p.org/h5p/embed/547225\"(.|\n)*> inside#"],
+            ["<a href=\"https://moodle.h5p.com/content/1290848995208939539/embed\">https://moodle.h5p.com/content/1290848995208939539/embed</a>",
+                "#<iframe src=\"https://moodle.h5p.com/content/1290848995208939539/embed\"[^>]+?>#"],
+            ["<a href=\"https://moodle.org\">https://moodle.h5p.com/content/1290848995208939539/embed</a>",
+                "#^((?!iframe).)*$#"],
+            ["<a href=\"https://moodle.h5p.com/content/1290848995208939539/embed\">link</a>",  "#^((?!iframe).)*$#"],
+            ["this is a text with an h5p url https://moodle.h5p.com/content/1290848995208939539/embed inside",
+                    "#this is a text with an h5p url <iframe src=\"https://moodle.h5p.com/content/1290848995208939539/embed\"(.|\n)*> inside#"],
             ["https://generic.wordpress.soton.ac.uk/altc/wp-admin/admin-ajax.php?action=h5p_embed&amp;id=13",
                     "#<iframe src=\"https://generic.wordpress.soton.ac.uk/altc/wp-admin/admin-ajax.php\?action=h5p_embed\&amp\;id=13\"[^>]+?>#"],
-            ["https://h5p.org/h5p/embed/547225 another content in the same page https://moodle.h5p.com/content/1290729733828858779/embed",
-                    "#<iframe src=\"https://h5p.org/h5p/embed/547225\"[^>]+?>((?!<iframe).)*<iframe src=\"https://moodle.h5p.com/content/1290729733828858779/embed\"[^>]+?>#"],
+            ["https://moodle.h5p.com/content/1290848995208939539/embed another content in the same page https://moodle.h5p.com/content/1290729733828858779/embed",
+                    "#<iframe src=\"https://moodle.h5p.com/content/1290848995208939539/embed\"[^>]+?>((?!<iframe).)*".
+                    "<iframe src=\"https://moodle.h5p.com/content/1290729733828858779/embed\"[^>]+?>#"],
             [$CFG->wwwroot."/pluginfile.php/5/user/private/interactive-video.h5p?export=1&embed=1",
                     "#<iframe src=\"{$CFG->wwwroot}/h5p/embed.php\?url=".rawurlencode("{$CFG->wwwroot}/pluginfile.php/5/user/private/interactive-video.h5p").
                     "&export=1&embed=1\"[^>]*?></iframe>#"],