From a80464e1c3d6ba0003e60da907d3bd9a6eb16b21 Mon Sep 17 00:00:00 2001
From: Justus Dieckmann <justusdieckmann@wwu.de>
Date: Tue, 5 Mar 2024 16:36:43 +0100
Subject: [PATCH] Rewrite filter to also accept <a href="..."> and <video
src="...">, for example
---
filter.php | 305 ++++++++++++++++++++++++++++++++++-------------------
1 file changed, 194 insertions(+), 111 deletions(-)
diff --git a/filter.php b/filter.php
index e5c3c44..edfbfad 100644
--- a/filter.php
+++ b/filter.php
@@ -20,39 +20,68 @@
* This filter will replace any links to opencast videos with the selected player from opencast.
*
* @package filter_opencast
- * @copyright 2018 Tamara Gunkel
+ * @copyright 2024 Justus Dieckmann and Tamara Gunkel, University of Münster
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
-
use mod_opencast\local\paella_transform;
/**
* Automatic opencast videos filter class.
*
* @package filter_opencast
- * @copyright 2018 Tamara Gunkel
+ * @copyright 2024 Justus Dieckmann and Tamara Gunkel, University of Münster
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class filter_opencast extends moodle_text_filter {
+ /**
+ * Get the content of the attribute $attributename from $tag.
+ * @param string $tag HTML-Tag.
+ * @param string $attributename Name of the attribute.
+ * @param string $attributecontentregex Regex of what the content of the attribute might be.
+ * @return string|null The content of the attribute or null, if it doesn't exist.
+ */
+ private static function get_attribute(string $tag, string $attributename, string $attributecontentregex = '.*'): string|null {
+ $pattern = "/$attributename=(['\"])($attributecontentregex)\\1/";
+ preg_match($pattern, $tag, $matches);
+ return $matches[2] ?? null;
+ }
+
+ /**
+ * Test whether $url matches one of the episodeurls.
+ * @param string $url The url to test.
+ * @param array $episodeurls array of [ocinstanceid, episoderegex, baseurl].
+ * @return array|null [ocinstanceid, episodeid] or null if there are no matches.
+ */
+ private static function test_url(string $url, array $episodeurls) : array|null {
+ foreach ($episodeurls as [$ocinstanceid, $episoderegex, $baseurl]) {
+ if (preg_match_all($episoderegex, $url, $matches)) {
+ return [$ocinstanceid, $matches[1][0]];
+ }
+ }
+ return null;
+ }
+
/**
* Replaces Opencast videos embedded in <video> tags by the paella player.
+ *
* @param string $text
* @param array $options
* @return array|mixed|string|string[]|null
- * @throws dml_exception
*/
public function filter($text, array $options = []) {
- global $PAGE, $OUTPUT;
- $i = 0;
- if (stripos($text, '</video>') === false) {
- // Performance shortcut - if there is no </video> tag, nothing can match.
+ if (preg_match('</(a|video)>', $text) !== 1) {
+ // Performance shortcut - if there are no </video> or </a> tags, nothing can match.
return $text;
}
- foreach (\tool_opencast\local\settings_api::get_ocinstances() as $ocinstance) {
+ // First section: (Relatively) quick check if there are episode urls in the text, and only look for these later.
+ // Improvable by combining all episode urls into one big regex if needed.
+ $ocinstances = \tool_opencast\local\settings_api::get_ocinstances();
+ $occurrences = [];
+ foreach ($ocinstances as $ocinstance) {
$episodeurls = get_config('filter_opencast', 'episodeurl_' . $ocinstance->id);
if (!$episodeurls) {
@@ -63,120 +92,174 @@ class filter_opencast extends moodle_text_filter {
$episodeurl = trim($episodeurl);
$urlparts = parse_url($episodeurl);
+ if (!isset($urlparts['scheme']) || !isset($urlparts['host'])) {
+ continue;
+ }
$baseurl = $urlparts['scheme'] . '://' . $urlparts['host'];
if (isset($urlparts['port'])) {
$baseurl .= ':' . $urlparts['port'];
}
- if (empty($episodeurl) || stripos($text, $baseurl) === false) {
- continue;
+ if (self::str_contains($text, $baseurl)) {
+ $episoderegex = "/" . preg_quote($episodeurl, "/") . "/";
+ $episoderegex = preg_replace('/\\\\\[EPISODEID\\\]/', '([0-9a-zA-Z\-]+)', $episoderegex);
+ $occurrences[] = [$ocinstance->id, $episoderegex, $baseurl];
}
+ }
+ }
- // Looking for tags.
- $matches = preg_split('/(<[^>]*>)/i', $text, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
- if ($matches) {
- $renderer = $PAGE->get_renderer('filter_opencast');
- $video = false;
- $width = false;
- $height = false;
-
- foreach ($matches as $match) {
- if (empty(trim($match))) {
- continue;
- }
- // Check if the match is a video tag.
- if (substr($match, 0, 6) === "<video") {
- $video = true;
- preg_match('/width="([0-9]+)"/', $match, $width);
- preg_match('/height="([0-9]+)"/', $match, $height);
- $width = $width ? $width[1] : $width;
- $height = $height ? $height[1] : $height;
- } else if ($video) {
- $video = false;
- if (substr($match, 0, 7) === "<source") {
-
- // Check if video is from opencast.
- if (strpos($match, $baseurl) === false) {
- $width = $height = false;
- continue;
- }
-
- // Extract url.
- preg_match_all('/<source[^>]+src=([\'"])(?<src>.+?)\1[^>]*>/i', $match, $result);
-
- // Change url for loading the (Paella) Player.
- $link = $result['src'][0];
-
- // Get episode id from link.
- $episoderegex = "/" . preg_quote($episodeurl, "/") . "/";
- $episoderegex = preg_replace('/\\\\\[EPISODEID\\\]/', '([0-9a-zA-Z\-]+)', $episoderegex);
- $nummatches = preg_match_all($episoderegex, $link, $episodeid);
-
- if (!$nummatches) {
- $width = $height = false;
- continue;
- }
-
- $data = paella_transform::get_paella_data_json($ocinstance->id, $episodeid[1][0]);
-
- if (!$data) {
- continue;
- }
-
- // Collect the needed data being submitted to the template.
- $mustachedata = new stdClass();
- $mustachedata->playerid = 'ocplayer_' . $i++;
- $mustachedata->configurl = (new moodle_url(get_config('filter_opencast', 'configurl_' . $ocinstance->id)))->out(false);
- $mustachedata->themeurl = (new moodle_url(get_config('mod_opencast', 'themeurl_' . $ocinstance->id)))->out(false);
- if (strpos($mustachedata->configurl, 'http') === false) {
- $mustachedata->configurl = (new moodle_url($mustachedata->configurl))->out();
- }
-
- $mustachedata->data = json_encode($data);
- $mustachedata->width = $width;
- $mustachedata->height = $height;
- $mustachedata->modplayerpath = (new moodle_url('/mod/opencast/player.html'))->out();
-
- if (isset($data['streams'])) {
- if (count($data['streams']) === 1) {
- $sources = $data['streams'][0]['sources'];
- $res = $sources[array_key_first($sources)][0]['res'];
- $resolution = $res['w'] . '/' . $res['h'];
- $mustachedata->resolution = $resolution;
-
- if ($width xor $height) {
- if ($width) {
- $mustachedata->height = $width * ($res['h'] / $res['w']);
- } else if ($height) {
- $mustachedata->width = $height * ($res['w'] / $res['h']);
- }
- }
- } else {
- if ($width && $height) {
- $mustachedata->width = $width;
- $mustachedata->height = $height;
- }
- }
- $newtext = $renderer->render_player($mustachedata);
- } else {
- $newtext = $OUTPUT->render(new \core\output\notification(
- get_string('erroremptystreamsources', 'mod_opencast'),
- \core\output\notification::NOTIFY_ERROR
- ));
- }
-
- // Replace video tag.
- $text = preg_replace('/<video(?:(?!<\/video>).)*?' . preg_quote($match, '/') . '.*?<\/video>/s',
- $newtext, $text, 1);
- }
- $width = $height = false;
+ if (empty($occurrences)) {
+ return $text;
+ }
+
+ // Second section: splitting the text into tags (and stuff between tags), and search for relevant urls in <a> and <video>.
+ $matches = preg_split('/(<[^>]*>)/i', $text, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
+ if (!$matches) {
+ return $text;
+ }
+
+ $i = 0;
+ $newtext = '';
+
+ $episode = null;
+ $currenttag = null;
+ $texttoreplace = '';
+ $width = null;
+ $height = null;
+
+ // We go through the complete text and transfer it match by match to $newtext.
+ // While we are going through interesting tags, $currenttag is set to 'video' or 'a' respectively.
+ // During that time, the matches are transferred to $texttoreplace instead. When we find the matching closing tag,
+ // ... we add either $texttoreplace to $newtext, or the html for the video player, if we found a matching opencast url.
+ foreach ($matches as $match) {
+ if ($currenttag) {
+ $texttoreplace .= $match;
+ if (self::str_starts_with($match, "</$currenttag")) {
+ $replacement = null;
+ if ($episode) {
+ $replacement = self::render_player($episode[0], $episode[1], $i++, $width, $height);
+ }
+ if ($replacement) {
+ $newtext .= $replacement;
+ } else {
+ $newtext .= $texttoreplace;
+ }
+ $episode = null;
+ $width = null;
+ $height = null;
+ $texttoreplace = null;
+ $currenttag = null;
+ } else if (!$episode && $currenttag === 'video' && self::str_starts_with($match, '<source ')) {
+ $src = self::get_attribute($match, 'src');
+ if ($src) {
+ $episode = self::test_url($src, $occurrences);
+ }
+ }
+ } else {
+ if (self::str_starts_with($match, '<video ')) {
+ $currenttag = 'video';
+ $width = self::get_attribute($match, 'width', '[0-9]+');
+ $height = self::get_attribute($match, 'height', '[0-9]+');
+ $src = self::get_attribute($match, 'src');
+ if ($src) {
+ $episode = self::test_url($src, $occurrences);
+ }
+ } else if (self::str_starts_with($match, '<a ')) {
+ $src = self::get_attribute($match, 'href');
+ if ($src) {
+ $episode = self::test_url($src, $occurrences);
+ // Only set currenttag if there is a recognized url,
+ // ... so that nested <a> or <video> tags can be matched otherwise.
+ if ($episode) {
+ $currenttag = 'a';
}
}
}
+ if ($currenttag) {
+ $texttoreplace .= $match;
+ } else {
+ $newtext .= $match;
+ }
+ }
+ }
+
+ return $newtext;
+ }
+
+ /**
+ * Render HTML for embedding video player.
+ * @param int $ocinstanceid Id of ocinstance.
+ * @param string $episodeid Id opencast episode.
+ * @param int $playerid Unique id to assign to player element.
+ * @param int|null $width Optionally width for player.
+ * @param int|null $height Optionally height for player.
+ * @return string|null
+ */
+ private static function render_player(int $ocinstanceid, string $episodeid, int $playerid,
+ $width = null, $height = null): string|null {
+ global $OUTPUT, $PAGE;
+
+ $data = paella_transform::get_paella_data_json($ocinstanceid, $episodeid);
+
+ if (!$data) {
+ return null;
+ }
+
+ // Collect the needed data being submitted to the template.
+ $mustachedata = new stdClass();
+ $mustachedata->playerid = 'ocplayer_' . $playerid;
+ $mustachedata->configurl =
+ (new moodle_url(get_config('filter_opencast', 'configurl_' . $ocinstanceid)))->out(false);
+ $mustachedata->themeurl =
+ (new moodle_url(get_config('mod_opencast', 'themeurl_' . $ocinstanceid)))->out(false);
+
+ $mustachedata->data = json_encode($data);
+ $mustachedata->width = $width;
+ $mustachedata->height = $height;
+ $mustachedata->modplayerpath = (new moodle_url('/mod/opencast/player.html'))->out(false);
+
+ if (isset($data['streams'])) {
+ if (count($data['streams']) === 1) {
+ $sources = $data['streams'][0]['sources'];
+ $res = $sources[array_key_first($sources)][0]['res'];
+ $resolution = $res['w'] . '/' . $res['h'];
+ $mustachedata->resolution = $resolution;
+
+ if ($width xor $height) {
+ if ($width) {
+ $mustachedata->height = $width * ($res['h'] / $res['w']);
+ } else if ($height) {
+ $mustachedata->width = $height * ($res['w'] / $res['h']);
+ }
+ }
}
+ $renderer = $PAGE->get_renderer('filter_opencast');
+ return $renderer->render_player($mustachedata);
+ } else {
+ return $OUTPUT->render(new \core\output\notification(
+ get_string('erroremptystreamsources', 'mod_opencast'),
+ \core\output\notification::NOTIFY_ERROR
+ ));
}
+ }
- // Return the same string except processed by the above.
- return $text;
+ /**
+ * Polyfill for str_contains for PHP 7.
+ * @param string $haystack
+ * @param string $needle
+ * @return bool
+ */
+ private static function str_contains(string $haystack, string $needle): bool {
+ return strpos($haystack, $needle) !== false;
+ }
+
+ /**
+ * Polyfill for str_starts_with for PHP 7.
+ * @param string $haystack
+ * @param string $needle
+ * @return bool
+ */
+ private static function str_starts_with(string $haystack, string $needle): bool {
+ return strpos($haystack, $needle) === 0;
}
}
--
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