Add retry limit to admin settings

Author: Vithusha Kethiri

classes/privacy/provider.php

@@ -27,7 +27,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 /**
- * The mod_modname module does not store any data.
+ * The filter_oembed module does not store any data.
  *
  */
 class provider implements \core_privacy\local\metadata\null_provider {

classes/provider/provider.php

@@ -181,9 +181,39 @@ public function get_oembed_request($text) {
      * @param string $url The consumer request URL.
      * @return array JSON decoded array.
      */
-    public function oembed_response($url) {
-        $ret = download_file_content($url, null, null, true, 300, 20, false, null, false);
-        return json_decode($ret->results, true);
+    public function oembed_response($url, $retryno = 0) {
+        static $cache;
+
+        if (!isset($cache)) {
+            $cache = \cache::make('filter_oembed', 'embeddata');
+        }
+
+        if ($ret = $cache->get(md5($url))) {
+            return json_decode($ret, true);
+        }
+
+        $curl = new \curl();
+        $ret = $curl->get($url);
+
+        // Check if curl call fails.
+        if ($curl->errno == CURLE_OK) {
+            $cache->set(md5($url), $ret);
+            $result = json_decode($ret, true);
+            return $result;
+        }
+
+        $retrylimit = get_config('filter_oembed', 'retrylimit');
+        // Check if error is due to network connection.
+        if (!in_array($curl->errno, [6, 7, 28])) {
+            return null;
+        }
+        // Try curl call up to $retrylimit times.
+        usleep(50000);
+        $retryno = (!is_int($retryno)) ? 0 : $retryno + 1;
+        if ($retryno >= $retrylimit) {
+            return null;
+        }
+        return $this->oembed_response($url, $retryno);
     }
 
     /**
@@ -224,6 +254,7 @@ protected function endpoints_regex(endpoint $endpoint) {
                     $find = ['.', '*'];
                     $replace = ['\.', '.*?'];
                     $url = str_replace($find, $replace, $url);
+                    $url = str_replace('.*??', '.*?\?', $url);
                     $regexarr[] = '(' . $url . ')';
                 }
 

filter.php

@@ -68,7 +68,7 @@ public function filter($text, array $options = array()) {
             return $text;
         }
 
-        $filtered = $text; // We need to return the original value if regex fails!
+        $filtered = $this->embed_extra_mappings($text); // We need to return the original value if regex fails!
         if ($targettag == 'divtag') {
             $search = '/\<div\s[^\>]*data-oembed-href="(.*?)"(.*?)>(.*?)\<\/div\>/';
         } else { // Using 'atag'.
@@ -84,6 +84,35 @@ public function filter($text, array $options = array()) {
         }
     }
 
+    private function embed_extra_mappings($html) {
+        $extra = get_config('filter_oembed', 'extra_mappings');
+        if (empty($extra)) {
+            return $html;
+        }
+
+        $mappings = explode("\n", trim($extra));
+        foreach ($mappings as $mapping) {
+            $mapping = trim($mapping);
+            $params = explode('=>', $mapping);
+            if (count($params) != 2) {
+                if ($params != '') { // Ignore empty lines.
+                    debugging('Invalid extra mapping: '.$mapping);
+                }
+                continue;
+            }
+
+            $html = $this->embed_extra_mapping($html, trim($params[0]), trim($params[1]));
+        }
+
+        return $html;
+    }
+
+    private function embed_extra_mapping($html, $url, $endpoint) {
+        $search = '#<a\s[^>]*href="('.$url.')"(.*?)>(.*?)</a>#is'; // URL to Link filter will create <a> tags.
+        $html = preg_replace_callback($search, 'self::find_oembeds_callback', $html);
+        return $html;
+    }
+
     /**
      * Callback function to be used by the main filter
      *

lang/en/filter_oembed.php

@@ -63,4 +63,9 @@
 $string['targettag'] = 'Target tag';
 $string['targettag_desc'] = 'What tag type should be filtered - anchors or divs with the oembed class.';
 $string['updateproviders'] = 'Update Oembed provider information.';
+$string['extramappings'] = 'Extra Mappings';
+$string['extramappingsdescription'] = 'Format: <b>REGEX => ENDPOINT</b><br />Where <i>REGEX</i> is what to replace and <i>ENDPOINT</i> is where to fetch the JSON parameters for the embed.';
 $string['privacy:metadata'] = 'Oembed filter does not store any personal data.';
+$string['once'] = 'Once';
+$string['retrylimit'] = 'Limit to retry getting filtered content';
+$string['times'] = '{$a} times';

settings.php

@@ -31,33 +31,49 @@
 
 use filter_oembed\service\oembed;
 
-$ADMIN->add('filtersettings', new admin_category('filteroembedfolder', get_string('filtername', 'filter_oembed')));
-$settings = new admin_settingpage($section, get_string('settings'));
+$ADMIN->add('filtersettings', new admin_category('filteroembedfolder', new lang_string('filtername', 'filter_oembed')));
+$settings = new admin_settingpage($section, new lang_string('settings'));
 
 if ($ADMIN->fulltree) {
     $targettags = [
-        'a' => get_string('atag', 'filter_oembed'),
-        'div' => get_string('divtag', 'filter_oembed')
+        'a' => new lang_string('atag', 'filter_oembed'),
+        'div' => new lang_string('divtag', 'filter_oembed')
     ];
 
     $config = get_config('filter_oembed');
 
+    $item = new admin_setting_configtextarea(
+        'filter_oembed/extra_mappings',
+        get_string('extramappings', 'filter_oembed'),
+        get_string('extramappingsdescription', 'filter_oembed'),
+        '',
+        PARAM_RAW
+    );
+    $settings->add($item);
+
     $item = new admin_setting_configselect(
         'filter_oembed/targettag',
-        get_string('targettag', 'filter_oembed'),
-        get_string('targettag_desc', 'filter_oembed'),
+        new lang_string('targettag', 'filter_oembed'),
+        new lang_string('targettag_desc', 'filter_oembed'),
         'atag',
         ['atag' => 'atag', 'divtag' => 'divtag']
     );
     $settings->add($item);
 
+    $retrylist = array('0' => new lang_string('none'), '1' => new lang_string('once', 'filter_oembed'),
+        '2' => new lang_string('times', 'filter_oembed', '2'),
+        '3' => new lang_string('times', 'filter_oembed', '3'));
+    $item = new admin_setting_configselect('filter_oembed/retrylimit',
+        new lang_string('retrylimit', 'filter_oembed'), '', '1', $retrylist);
+    $settings->add($item);
+
     $item = new admin_setting_configcheckbox('filter_oembed/lazyload', new lang_string('lazyload', 'filter_oembed'), '', 1);
     $settings->add($item);
 }
 
 $ADMIN->add('filteroembedfolder', $settings);
 
 $ADMIN->add('filteroembedfolder', new admin_externalpage('filter_oembed_providers',
-    get_string('manageproviders', 'filter_oembed'), new moodle_url('/filter/oembed/manageproviders.php')));
+    new lang_string('manageproviders', 'filter_oembed'), new moodle_url('/filter/oembed/manageproviders.php')));
 
 $settings = null;