GNUsocial/gnu-social
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Swap the Services_oEmbed wrapper in oEmbedHelper out for doing it ourselves...

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- workaround for providers that are skimpy on their data, such as missing width/height or thumbnail_width/thumbnail_height
- workaround for YFrog listing "image" instead of "photo" type
- generally more lax about formatting: if it comes back and looks kinda ok, we'll take it.
- discovery uses system HTML parser, should be more robust if the links include things like ampersands with proper HTML-level escaping
This commit is contained in:
Brion Vibber
2010-11-15 11:25:38 -08:00
parent 1c90d09ec8
commit c8445299c7
1 changed files with 126 additions and 49 deletions
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175
lib/oembedhelper.php
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@@ -20,11 +20,10 @@
if (!defined('STATUSNET')) {
exit(1);
}
require_once INSTALLDIR.'/extlib/Services/oEmbed.php';
/**
* Utility class to wrap Services_oEmbed:
* Utility class to wrap basic oEmbed lookups.
*
* Blacklisted hosts will use an alternate lookup method:
* - Twitpic
@@ -89,43 +88,134 @@ class oEmbedHelper
$api = self::$apiMap[$host];
common_log(LOG_INFO, 'QQQ: going to: ' . $api);
} else {
$api = false;
common_log(LOG_INFO, 'QQQ: no map for ' . $host);
try {
$api = self::discover($url);
} catch (Exception $e) {
// Discovery failed... fall back to oohembed if enabled.
$oohembed = common_config('oohembed', 'endpoint');
if ($oohembed) {
$api = $oohembed;
} else {
throw $e;
}
}
common_log(LOG_INFO, 'QQQ: going to: ' . $api);
}
return self::getObjectFrom($api, $url, $params);
}
/**
* Actually do an oEmbed lookup to a particular API endpoint,
* or to the autodiscovered target, or to oohembed.
* Perform basic discovery.
* @return string
*/
static function discover($url)
{
// @fixme ideally skip this for non-HTML stuff!
$body = self::http($url);
return self::discoverFromHTML($url, $body);
}
/**
* Partially ripped from OStatus' FeedDiscovery class.
*
* @param mixed $api string or false: oEmbed API endpoint URL
* @param string $url source URL, used to resolve relative links
* @param string $body HTML body text
* @return mixed string with URL or false if no target found
*/
static function discoverFromHTML($url, $body)
{
// DOMDocument::loadHTML may throw warnings on unrecognized elements,
// and notices on unrecognized namespaces.
$old = error_reporting(error_reporting() & ~(E_WARNING | E_NOTICE));
$dom = new DOMDocument();
$ok = $dom->loadHTML($body);
error_reporting($old);
if (!$ok) {
throw new oEmbedHelper_BadHtmlException();
}
// Ok... now on to the links!
$feeds = array(
'application/json+oembed' => false,
);
$nodes = $dom->getElementsByTagName('link');
for ($i = 0; $i < $nodes->length; $i++) {
$node = $nodes->item($i);
if ($node->hasAttributes()) {
$rel = $node->attributes->getNamedItem('rel');
$type = $node->attributes->getNamedItem('type');
$href = $node->attributes->getNamedItem('href');
if ($rel && $type && $href) {
$rel = array_filter(explode(" ", $rel->value));
$type = trim($type->value);
$href = trim($href->value);
if (in_array('alternate', $rel) && array_key_exists($type, $feeds) && empty($feeds[$type])) {
// Save the first feed found of each type...
$feeds[$type] = $href;
}
}
}
}
// Return the highest-priority feed found
foreach ($feeds as $type => $url) {
if ($url) {
return $url;
}
}
return false;
throw new oEmbedHelper_DiscoveryException();
}
/**
* Actually do an oEmbed lookup to a particular API endpoint.
*
* @param string $api oEmbed API endpoint URL
* @param string $url target URL to look up info about
* @param array $params
* @return object
*/
static protected function getObjectFrom($api, $url, $params=array())
static function getObjectFrom($api, $url, $params=array())
{
$options = array();
if ($api) {
$options[Services_oEmbed::OPTION_API] = $api;
$params['url'] = $url;
$params['format'] = 'json';
$data = self::json($api, $params);
return self::normalize($data);
}
/**
* Normalize oEmbed format.
*
* @param object $orig
* @return object
*/
static function normalize($orig)
{
$data = clone($orig);
if (empty($data->type)) {
throw new Exception('Invalid oEmbed data: no type field.');
}
try {
$oEmbed = new Services_oEmbed_Tweaked($url, $options);
} catch (Services_oEmbed_Exception_NoSupport $e) {
// Discovery failed... fall back to oohembed if enabled.
$oohembed = common_config('oohembed', 'endpoint');
if ($oohembed) {
$options[Services_oEmbed::OPTION_API] = $oohembed;
$oEmbed = new Services_oEmbed_Tweaked($url, $options);
} else {
throw $e;
if ($data->type == 'image') {
// YFrog does this.
$data->type = 'photo';
}
if (isset($data->thumbnail_url)) {
if (!isset($data->thumbnail_width)) {
// !?!?!
$data->thumbnail_width = common_config('attachments', 'thumb_width');
$data->thumbnail_height = common_config('attachments', 'thumb_height');
}
}
// And.... let's go look it up!
return $oEmbed->getObject($params);
return $data;
}
/**
@@ -212,35 +302,22 @@ class oEmbedHelper
}
}
class Services_oEmbed_Tweaked extends Services_oEmbed
class oEmbedHelper_Exception extends Exception
{
protected function discover($url)
{
$api = parent::discover($url);
if (strpos($api, '?') !== false) {
// Services_oEmbed doesn't expect to find existing params
// on its API endpoint, which may surprise you since the
// spec says discovery URLs should include parameters... :)
//
// Appending a '&' on the end keeps the later-appended '?'
// from breaking whatever the first parameters was.
return $api . '&';
}
return $api;
}
}
public function getObject(array $params = array())
class oEmbedHelper_BadHtmlException extends oEmbedHelper_Exception
{
function __construct($previous=null)
{
$api = $this->options[self::OPTION_API];
if (strpos($api, '?') !== false) {
// The Services_oEmbed code appends a '?' on the end, which breaks
// the next parameter which may be something important like
// maxwidth.
//
// Sticking this bogus entry into our parameters gets us past it.
$params = array_merge(array('statusnet' => 1), $params);
}
return parent::getObject($params);
return parent::__construct('Bad HTML in discovery data.', 0, $previous);
}
}
}
class oEmbedHelper_DiscoveryException extends oEmbedHelper_Exception
{
function __construct($previous=null)
{
return parent::__construct('No oEmbed discovery data.', 0, $previous);
}
}