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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file contains all the common stuff to be used in RSS System
*
* @package core_rss
* @category rss
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Build the URL for the RSS feed and add it as a header
*
* @param stdClass $context The context under which the URL should be created
* @param string $componentname The name of the component for which the RSS feed exists
* @param stdClass $componentinstance The instance of the component
* @param string $title Name for the link to be added to the page header
*/
function rss_add_http_header($context, $componentname, $componentinstance, $title) {
global $PAGE, $USER;
$componentid = null;
if (is_object($componentinstance)) {
$componentid = $componentinstance->id;
} else {
$componentid = $componentinstance;
}
$rsspath = rss_get_url($context->id, $USER->id, $componentname, $componentid);
$PAGE->add_alternate_version($title, $rsspath, 'application/rss+xml');
}
/**
* Print the link for the RSS feed with the correct RSS icon
*
* @param stdClass $contextid The id of the context under which the URL should be created
* @param int $userid The source of the RSS feed (site/course/group/user)
* @param string $componentname The name of the component for which the feed exists
* @param string $id The name by which to call the RSS File
* @param string $tooltiptext The tooltip to be displayed with the link
* @return string HTML output for the RSS link
*/
function rss_get_link($contextid, $userid, $componentname, $id, $tooltiptext='') {
global $OUTPUT;
static $rsspath = '';
$rsspath = rss_get_url($contextid, $userid, $componentname, $id);
return '<a href="'. $rsspath .'">' . $OUTPUT->pix_icon('i/rss', $tooltiptext) . '</a>';
}
/**
* This function returns the URL for the RSS XML file.
*
* @param int $contextid the course id
* @param int $userid the current user id
* @param string $componentname the name of the current component. For example "forum"
* @param string $additionalargs For modules, module instance id
* @return string the url of the RSS feed
*/
function rss_get_url($contextid, $userid, $componentname, $additionalargs) {
global $CFG;
if (empty($userid)) {
$userid = guest_user()->id;
}
$usertoken = rss_get_token($userid);
$url = '/rss/file.php';
return moodle_url::make_file_url($url, '/'.$contextid.'/'.$usertoken.'/'.$componentname.'/'.$additionalargs.'/rss.xml');
}
/**
* Print the link for the RSS feed with the correct RSS icon (Theme based)
*
* @param stdClass $contextid The id of the context under which the URL should be created
* @param int $userid The source of the RSS feed (site/course/group/user)
* @param string $componentname The name of the component for which the feed exists
* @param string $id The name by which to call the RSS File
* @param string $tooltiptext The tooltip to be displayed with the link
*/
function rss_print_link($contextid, $userid, $componentname, $id, $tooltiptext='') {
print rss_get_link($contextid, $userid, $componentname, $id, $tooltiptext);
}
/**
* Given an object, deletes all RSS files associated with it.
*
* @param string $componentname the name of the module ie 'forum'. Used to construct the cache path.
* @param stdClass $instance An object with an id member variable ie $forum, $glossary.
*/
function rss_delete_file($componentname, $instance) {
global $CFG;
$dirpath = "$CFG->cachedir/rss/$componentname";
if (is_dir($dirpath)) {
if (!$dh = opendir($dirpath)) {
error_log("Directory permission error. RSS directory store for component '{$componentname}' exists but cannot be opened.", DEBUG_DEVELOPER);
return;
}
while (false !== ($filename = readdir($dh))) {
if ($filename!='.' && $filename!='..') {
if (preg_match("/{$instance->id}_/", $filename)) {
unlink("$dirpath/$filename");
}
}
}
}
}
/**
* Are RSS feeds enabled for the supplied module instance?
*
* @param string $modname The name of the module to be checked
* @param stdClass $instance An instance of an activity module ie $forum, $glossary.
* @param bool $hasrsstype Should there be a rsstype member variable?
* @param bool $hasrssarticles Should there be a rssarticles member variable?
* @return bool whether or not RSS is enabled for the module
*/
function rss_enabled_for_mod($modname, $instance=null, $hasrsstype=true, $hasrssarticles=true) {
if ($hasrsstype) {
if (empty($instance->rsstype) || $instance->rsstype==0) {
return false;
}
}
//have they set the RSS feed to return 0 results?
if ($hasrssarticles) {
if (empty($instance->rssarticles) || $instance->rssarticles==0) {
return false;
}
}
if (!empty($instance) && !instance_is_visible($modname,$instance)) {
return false;
}
return true;
}
/**
* This function saves to file the rss feed specified in the parameters
*
* @param string $componentname the module name ie forum. Used to create a cache directory.
* @param string $filename the name of the file to be created ie "rss.xml"
* @param string $contents the data to be written to the file
* @param bool $expandfilename whether or not the fullname of the RSS file should be used
* @return bool whether the save was successful or not
*/
function rss_save_file($componentname, $filename, $contents, $expandfilename=true) {
global $CFG;
$status = true;
if (! $basedir = make_cache_directory ('rss/'. $componentname)) {
//Cannot be created, so error
$status = false;
}
if ($status) {
$fullfilename = $filename;
if ($expandfilename) {
$fullfilename = rss_get_file_full_name($componentname, $filename);
}
$rss_file = fopen($fullfilename, "w");
if ($rss_file) {
$status = fwrite ($rss_file, $contents);
fclose($rss_file);
} else {
$status = false;
}
}
return $status;
}
/**
* Retrieve the location and file name of a cached RSS feed
*
* @param string $componentname the name of the component the RSS feed is being created for
* @param string $filename the name of the RSS FEED
* @return string The full name and path of the RSS file
*/
function rss_get_file_full_name($componentname, $filename) {
global $CFG;
return "$CFG->cachedir/rss/$componentname/$filename.xml";
}
/**
* Construct the file name of the RSS File
*
* @param stdClass $instance the instance of the source of the RSS feed
* @param string $sql the SQL used to produce the RSS feed
* @param array $params the parameters used in the SQL query
* @return string the name of the RSS file
*/
function rss_get_file_name($instance, $sql, $params = array()) {
if ($params) {
// If a parameters array is passed, then we want to
// serialize it and then concatenate it with the sql.
// The reason for this is to generate a unique filename
// for queries using the same sql but different parameters.
asort($params);
$serializearray = serialize($params);
return $instance->id.'_'.md5($sql . $serializearray);
} else {
return $instance->id.'_'.md5($sql);
}
}
/**
* This function return all the common headers for every rss feed in the site
*
* @param string $title the title for the RSS Feed
* @param string $link the link for the origin of the RSS feed
* @param string $description the description of the contents of the RSS feed
* @return bool|string the standard header for the RSS feed
*/
function rss_standard_header($title = NULL, $link = NULL, $description = NULL) {
global $CFG, $USER, $OUTPUT;
$status = true;
$result = "";
$site = get_site();
if ($status) {
//Calculate title, link and description
if (empty($title)) {
$title = format_string($site->fullname);
}
if (empty($link)) {
$link = $CFG->wwwroot;
}
if (empty($description)) {
$description = $site->summary;
}
//xml headers
$result .= "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
$result .= "<rss version=\"2.0\">\n";
//open the channel
$result .= rss_start_tag('channel', 1, true);
//write channel info
$result .= rss_full_tag('title', 2, false, strip_tags($title));
$result .= rss_full_tag('link', 2, false, $link);
$result .= rss_full_tag('description', 2, false, $description);
$result .= rss_full_tag('generator', 2, false, 'Moodle');
if (!empty($USER->lang)) {
$result .= rss_full_tag('language', 2, false, substr($USER->lang,0,2));
}
$today = getdate();
$result .= rss_full_tag('copyright', 2, false, '(c) '. $today['year'] .' '. format_string($site->fullname));
/*
if (!empty($USER->email)) {
$result .= rss_full_tag('managingEditor', 2, false, fullname($USER));
$result .= rss_full_tag('webMaster', 2, false, fullname($USER));
}
*/
//write image info
$rsspix = $OUTPUT->image_url('i/rsssitelogo');
//write the info
$result .= rss_start_tag('image', 2, true);
$result .= rss_full_tag('url', 3, false, $rsspix);
$result .= rss_full_tag('title', 3, false, 'moodle');
$result .= rss_full_tag('link', 3, false, $CFG->wwwroot);
$result .= rss_full_tag('width', 3, false, '140');
$result .= rss_full_tag('height', 3, false, '35');
$result .= rss_end_tag('image', 2, true);
}
if (!$status) {
return false;
} else {
return $result;
}
}
/**
* Generates the rss XML code for every item passed in the array
*
* item->title: The title of the item
* item->author: The author of the item. Optional !!
* item->pubdate: The pubdate of the item
* item->link: The link url of the item
* item->description: The content of the item
*
* @param array $items an array of item objects
* @return bool|string the rss XML code for every item passed in the array
*/
function rss_add_items($items) {
global $CFG;
$result = '';
if (!empty($items)) {
foreach ($items as $item) {
$result .= rss_start_tag('item',2,true);
//Include the category if exists (some rss readers will use it to group items)
if (isset($item->category)) {
$result .= rss_full_tag('category',3,false,$item->category);
}
if (isset($item->tags)) {
$attributes = array();
if (isset($item->tagscheme)) {
$attributes['domain'] = s($item->tagscheme);
}
foreach ($item->tags as $tag) {
$result .= rss_full_tag('category', 3, false, $tag, $attributes);
}
}
$result .= rss_full_tag('title',3,false,strip_tags($item->title));
$result .= rss_full_tag('link',3,false,$item->link);
$result .= rss_add_enclosures($item);
$result .= rss_full_tag('pubDate',3,false,gmdate('D, d M Y H:i:s',$item->pubdate).' GMT'); # MDL-12563
//Include the author if exists
if (isset($item->author) && !empty($item->author)) {
//$result .= rss_full_tag('author',3,false,$item->author);
//We put it in the description instead because it's more important
//for moodle than most other feeds, and most rss software seems to ignore
//the author field ...
$item->description = get_string('byname','',$item->author).'. &nbsp;<p>'.$item->description.'</p>';
}
$result .= rss_full_tag('description',3,false,$item->description);
$result .= rss_full_tag('guid',3,false,$item->link,array('isPermaLink' => 'true'));
$result .= rss_end_tag('item',2,true);
}
} else {
$result = false;
}
return $result;
}
/**
* This function return all the common footers for every rss feed in the site.
*
* @return string
*/
function rss_standard_footer() {
$status = true;
$result = '';
$result .= rss_end_tag('channel', 1, true);
$result .= '</rss>';
return $result;
}
/**
* This function return an error xml file (string) to be sent when a rss is required (file.php) and something goes wrong
*
* @param string $errortype Type of error to send, default is rsserror
* @return stdClass returns a XML Feed with an error message in it
*/
function rss_geterrorxmlfile($errortype = 'rsserror') {
global $CFG;
$return = '';
//XML Header
$return = rss_standard_header();
//XML item
if ($return) {
$item = new stdClass();
$item->title = "RSS Error";
$item->link = $CFG->wwwroot;
$item->pubdate = time();
$item->description = get_string($errortype);
$return .= rss_add_items(array($item));
}
//XML Footer
if ($return) {
$return .= rss_standard_footer();
}
return $return;
}
/**
* Get the ID of the user from a given RSS Token
*
* @param string $token the RSS token you would like to use to find the user id
* @return int The user id
*/
function rss_get_userid_from_token($token) {
global $DB;
$sql = 'SELECT u.id FROM {user} u
JOIN {user_private_key} k ON u.id = k.userid
WHERE u.deleted = 0 AND u.confirmed = 1
AND u.suspended = 0 AND k.value = ?';
return $DB->get_field_sql($sql, array($token), IGNORE_MISSING);
}
/**
* Get the RSS Token from a given user id
*
* @param int $userid The user id
* @return string the RSS token for the user
*/
function rss_get_token($userid) {
return get_user_key('rss', $userid);
}
/**
* Removes the token for the given user from the DB
* @param int $userid The user id for the token you wish to delete
*/
function rss_delete_token($userid) {
delete_user_key('rss', $userid);
}
/**
* Return the xml start tag
*
* @param string $tag the xml tag name
* @param int $level the indentation level
* @param bool $endline whether or not to start new tags on a new line
* @param array $attributes the attributes of the xml tag
* @return string the xml start tag
*/
function rss_start_tag($tag,$level=0,$endline=false,$attributes=null) {
if ($endline) {
$endchar = "\n";
} else {
$endchar = "";
}
$attrstring = '';
if (!empty($attributes) && is_array($attributes)) {
foreach ($attributes as $key => $value) {
$attrstring .= " ".$key."=\"".$value."\"";
}
}
return str_repeat(" ",$level*2)."<".$tag.$attrstring.">".$endchar;
}
/**
* Return the xml end tag
* @param string $tag the xml tag name
* @param int $level the indentation level
* @param bool $endline whether or not to start new tags on a new line
* @return string the xml end tag
*/
function rss_end_tag($tag,$level=0,$endline=true) {
if ($endline) {
$endchar = "\n";
} else {
$endchar = "";
}
return str_repeat(" ",$level*2)."</".$tag.">".$endchar;
}
/**
* Return the while xml element, including content
*
* @param string $tag the xml tag name
* @param int $level the indentation level
* @param bool $endline whether or not to start new tags on a new line
* @param string $content the text to go inside the tag
* @param array $attributes the attributes of the xml tag
* @return string the whole xml element
*/
function rss_full_tag($tag,$level=0,$endline=true,$content,$attributes=null) {
$st = rss_start_tag($tag,$level,$endline,$attributes);
$co="";
$co = preg_replace("/\r\n|\r/", "\n", htmlspecialchars($content));
$et = rss_end_tag($tag,0,true);
return $st.$co.$et;
}
/**
* Adds RSS Media Enclosures for "podcasting" by including attachments that
* are specified in the item->attachments field.
*
* @param stdClass $item representing an RSS item
* @return string RSS enclosure tags
*/
function rss_add_enclosures($item){
global $CFG;
$returnstring = '';
// list of media file extensions and their respective mime types
include_once($CFG->libdir.'/filelib.php');
$mediafiletypes = get_mimetypes_array();
// take into account attachments (e.g. from forum) - with these, we are able to know the file size
if (isset($item->attachments) && is_array($item->attachments)) {
foreach ($item->attachments as $attachment){
$extension = strtolower(substr($attachment->url, strrpos($attachment->url, '.')+1));
if (isset($mediafiletypes[$extension]['type'])) {
$type = $mediafiletypes[$extension]['type'];
} else {
$type = 'document/unknown';
}
$returnstring .= "\n<enclosure url=\"$attachment->url\" length=\"$attachment->length\" type=\"$type\" />\n";
}
}
return $returnstring;
}