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refactored a big scary function a bit. hopefully it is more readable …

…this way. this change also paved the way for extra caching in the block's config structure.
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1 parent 37fe05a commit 79dd93a9208c84eef9cc9e38f4ee3da1a0b784f1 dhawes committed Jan 21, 2005
Showing with 83 additions and 86 deletions.
  1. +83 −86 rss/rsslib.php
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@@ -335,24 +335,14 @@ function rss_full_tag($tag,$level=0,$endline=true,$content,$to_utf=true) {
}
/**
- * Determines whether or not to get a news feed remotely or from cache and reads it into a string
- * @param int rssid - id of feed in blog_rss table
- * @param string url - url of remote feed
- * @param string type - either 'A' or 'R' where A is an atom feed and R is either rss or rdf
- * @return Atom|MagpieRSS|null This function returns an Atom object in the case of an Atom feed, a MagpieRSS object in the case of an RDF/RSS feed or null if there was an error loading the remote feed.
- * NOTE that this function requires allow_url_fopen be On in your php.ini file
- * (it may be off for security by your web host)
+ * Determine by rss id if the raw xml is cached on the file system
+ * @param int $rssid The id of this feed in the rss table
+ * @return bool False if cache file is missing or expired
*/
-function rss_get_feed($rssid, $url, $type) {
-
+function rss_cache_valid_by_id($rssid) {
global $CFG;
- $writetofile = false;
- $errorstring = '';
-
- $urlfailurestring = '<p>Failed to open remote news feed at: ' . $url .'</p><ul>Troubleshooting suggestions:<li> Ensure that the setting <strong>allow_url_fopen</strong> is <strong>On</strong> in the php.ini. For more details on why this setting is needed for this file wrapper call to work please refer to <a href="http://us2.php.net/filesystem">http://us2.php.net/filesystem</a></li><li>Ensure that you do not have a proxy enabled between your server and the remote site. If it is possible for you to launch a web browser on your server then you can test this by load the remote URL on the server itself.</li></ul>';
- $filefailurestring = 'Could not open the file located at: ';
$secs = $CFG->block_rss_timeout * 60;
-
+
// If moodle dataroot cache folder is missing create it
if (!file_exists($CFG->dataroot .'/cache/')) {
mkdir($CFG->dataroot .'/cache');
@@ -364,96 +354,103 @@ function rss_get_feed($rssid, $url, $type) {
$file = $CFG->dataroot .'/cache/rsscache/'. $rssid .'.xml';
// echo "file = ". $file; //debug
-
- //if feed in cache
+
if (file_exists($file)) {
- //check age of cache file
+ //check age of cached xml file
// echo "file exists $file"; //debug
-
- //get file information capturing any error information
- ob_start();
- $data = stat($file);
- $errorstring .= ob_get_contents();
- ob_end_clean();
+
+ //get file information ignoring error information
+ $data = @stat($file);
$now = time();
//Note: there would be a problem here reading data[10] if the above stat() call failed
- if (($now - $data[10]) > $secs) {
- // The cached file has expired. Attempt to read fresh from source
- $xml = load_feed_from_url($url);
- if (!empty($xml) && !empty($xml->xml) && empty($xml->ERROR)) {
- //success
- $writetofile = true;
- } else {
- // Failed to load remote feed. Since the file exists attempt to read from cache
- if ($CFG->debug) {
- if (isset($xml) && isset($xml->ERROR)) {
- $errorstring = $xml->ERROR . $errorstring .'<br />';
- }
- $errorstring = $urlfailurestring .'<br /><br />'. $errorstring .'<br />';
- }
- $xml = load_feed_from_file($file);
- if (!empty($xml) && empty($xml->xml) && !empty($xml->ERROR)) {
- // Failed to load from cache as well!
- if ($CFG->debug) {
- if (!empty($xml) && !empty($xml->ERROR)) {
- $errorstring = $xml->ERROR . $errorstring;
- }
- $errorstring = $filefailurestring . $file .'<br /><br />'. $errorstring .'<br />';
- $err->ERROR = $errorstring .'<br />';
- return $err;
- }
- }
- }
- } else {
- // Cached file has not expired. Attempt to read from cached file.
- $xml = load_feed_from_file($file);
- if (!empty($xml) && empty($xml->xml) && !empty($xml->ERROR)) {
- // Failed to load from cache, attempt to read from source
- if ($CFG->debug) {
- if (!empty($xml) && !empty($xml->ERROR)) {
- $errorstring = $xml->ERROR . $errorstring .'<br />';
- }
- $errorstring = $filefailurestring . $file .'<br /><br />'. $errorstring .'<br />';
- }
- $xml = load_feed_from_url($url);
- if (!empty($xml) && !empty($xml->xml) && empty($xml->ERROR)) {
- // success
- $writetofile = true;
- } else {
- // Failed to read from source as well!
- if ($CFG->debug) {
- if (!empty($xml) && !empty($xml->ERROR)) {
- $errorstring = $xml->ERROR . $errorstring;
- }
- $errorstring = $urlfailurestring .'<br /><br />'. $errorstring .'<br />';
- $err->ERROR = $errorstring .'<br />';
- return $err;
- }
- return;
+ if (empty($data)) {
+ // error getting stat on file, return
+ return false;
+ }
+ if ( ($now - $data[10]) > $secs) {
+ // The cached file has expired.
+ return false;
+ }
+ // no error, cache file is valid
+ return true;
+ }
+}
+
+/**
+ * Determines whether or not to get a news feed remotely or from cache and reads it into a string
+ * @param int rssid - id of feed in blog_rss table
+ * @param string url - url of remote feed
+ * @param string type - either 'A' or 'R' where A is an atom feed and R is either rss or rdf
+ * @return Atom|MagpieRSS|null This function returns an Atom object in the case of an Atom feed, a MagpieRSS object in the case of an RDF/RSS feed or null if there was an error loading the remote feed.
+ * NOTE that this function requires allow_url_fopen be On in your php.ini file
+ * (it may be off for security by your web host)
+ */
+function rss_get_feed($rssid, $url, $type) {
+ global $CFG;
+ $errorstring = '';
+ $urlfailurestring = '<p>Failed to open remote news feed at: ' . $url .'</p><ul>Troubleshooting suggestions:<li> Ensure that the setting <strong>allow_url_fopen</strong> is <strong>On</strong> in the php.ini. For more details on why this setting is needed for this file wrapper call to work please refer to <a href="http://us2.php.net/filesystem">http://us2.php.net/filesystem</a></li><li>Ensure that you do not have a proxy enabled between your server and the remote site. If it is possible for you to launch a web browser on your server then you can test this by load the remote URL on the server itself.</li></ul>';
+ $filefailurestring = 'Could not open the file located at: ';
+ $file = $CFG->dataroot .'/cache/rsscache/'. $rssid .'.xml';
+
+ // some flags to be used in managing where the rss data is read from
+ $writetofile = false;
+ $readfromfile = false;
+ $readfromurl = false;
+ $cachefilevalid = false;
+
+ if (rss_cache_valid_by_id($rssid)) {
+ //valid xml feed info in cache, read from file
+ $readfromfile = true;
+ $cachefilevalid = true;
+ } else {
+ // xml feed missing or expired, read from source url
+ $readfromurl = true;
+ }
+
+ if ($readfromfile) {
+ // Cached file has not expired. Attempt to read from cached file.
+ $xml = load_feed_from_file($file);
+ if (!empty($xml) && empty($xml->xml) && !empty($xml->ERROR)) {
+ // Failed to load from cache, attempt to read from source
+ if ($CFG->debug) {
+ if (!empty($xml) && !empty($xml->ERROR)) {
+ $errorstring = $xml->ERROR . $errorstring .'<br />';
}
+ $errorstring = $filefailurestring . $file .'<br /><br />'. $errorstring .'<br />';
}
+ $readfromurl = true; // read from file failed, try to get from source next
}
- } else {
- // No cached file at all, read from source
+ }
+
+ if ($readfromurl) {
$xml = load_feed_from_url($url);
if (!empty($xml) && !empty($xml->xml) && empty($xml->ERROR)) {
//success
$writetofile = true;
} else {
- // Failed to read from source url!
+ // Failed to load remote feed. Since the file exists attempt to read from cache
if ($CFG->debug) {
- if (!empty($xml) && !empty($xml->ERROR)) {
- $errorstring = $xml->ERROR . $errorstring .'<br />';
+ if (isset($xml) && isset($xml->ERROR)) {
+ $errorstring = $xml->ERROR . $errorstring .'<br />';
}
$errorstring = $urlfailurestring .'<br /><br />'. $errorstring .'<br />';
- $err->ERROR = $errorstring .'<br />';
- return $err;
}
- return;
+ $xml = load_feed_from_file($file);
+ if (!empty($xml) && empty($xml->xml) && !empty($xml->ERROR)) {
+ // Failed to load from cache as well!
+ if ($CFG->debug) {
+ if (!empty($xml) && !empty($xml->ERROR)) {
+ $errorstring = $xml->ERROR . $errorstring;
+ }
+ $errorstring = $filefailurestring . $file .'<br /><br />'. $errorstring .'<br />';
+ $err->ERROR = $errorstring .'<br />';
+ return $err;
+ }
+ }
}
}
-
+
// echo 'DEBUG: raw xml was loaded successfully:<br />';//debug
//print_object($xml); //debug

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