Encapsulate the oEmbed -> oohembed fallback into oEmbedHelper class. Also added a chance to whitelist sites that don't show discovery info but do have oEmbed API endpoints, and to provide alternate APIs for some common services.

Newly supported:
- TwitPic: added a local function using TwitPic's API, since the oohembed implementation for TwitPic produced invalid output which Services_oEmbed rejects. (bug filed upstream)

Tweaked...
- Flickr: works, now using whitelist to use their endpoint directly instead of going through oohembed
- Youtube: worked around a bug in Services_oEmbed which broke the direct use of API discovery info, so we don't have to use oohembed.

Not currently working...
- YFrog: whitelisting their endpoint directly as the oohembed output is broken, but this doesn't appear to work currently as I think things are confused by YFrog's servers giving a '204 No Content' response on our HEAD checks on the original link.
This commit is contained in:
Brion Vibber 2010-11-12 17:41:35 -08:00
parent 398e622fec
commit 4f323efdf7
2 changed files with 251 additions and 15 deletions

View File

@ -59,25 +59,15 @@ class File_oembed extends Memcached_DataObject
}
function _getOembed($url) {
require_once INSTALLDIR.'/extlib/Services/oEmbed.php';
$parameters = array(
'maxwidth' => common_config('attachments', 'thumb_width'),
'maxheight' => common_config('attachments', 'thumb_height'),
);
try{
$oEmbed = new Services_oEmbed($url);
$object = $oEmbed->getObject($parameters);
return $object;
}catch(Exception $e){
try{
$oEmbed = new Services_oEmbed($url, array(
Services_oEmbed::OPTION_API => common_config('oohembed', 'endpoint')
));
$object = $oEmbed->getObject($parameters);
return $object;
}catch(Exception $ex){
return false;
}
try {
return oEmbedHelper::getObject($url, $parameters);
} catch (Exception $e) {
common_log(LOG_ERR, "Error during oembed lookup for $url - " . $e->getMessage());
return false;
}
}

246
lib/oembedhelper.php Normal file
View File

@ -0,0 +1,246 @@
<?php
/*
* StatusNet - the distributed open-source microblogging tool
* Copyright (C) 2008-2010, StatusNet, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
if (!defined('STATUSNET')) {
exit(1);
}
require_once INSTALLDIR.'/extlib/Services/oEmbed.php';
/**
* Utility class to wrap Services_oEmbed:
*
* Blacklisted hosts will use an alternate lookup method:
* - Twitpic
*
* Whitelisted hosts will use known oEmbed API endpoints:
* - Flickr, YFrog
*
* Sites that provide discovery links will use them directly; a bug
* in use of discovery links with query strings is worked around.
*
* Others will fall back to oohembed (unless disabled).
* The API endpoint can be configured or disabled through config
* as 'oohembed'/'endpoint'.
*/
class oEmbedHelper
{
protected static $apiMap = array(
'flickr.com' => 'http://www.flickr.com/services/oembed/',
'yfrog.com' => 'http://www.yfrog.com/api/oembed',
);
protected static $functionMap = array(
'twitpic.com' => 'oEmbedHelper::twitPic',
);
/**
* Perform or fake an oEmbed lookup for the given resource.
*
* Some known hosts are whitelisted with API endpoints where we
* know they exist but autodiscovery data isn't available.
* If autodiscovery links are missing and we don't recognize the
* host, we'll pass it to oohembed.com's public service which
* will either proxy or fake info on a lot of sites.
*
* A few hosts are blacklisted due to known problems with oohembed,
* in which case we'll look up the info another way and return
* equivalent data.
*
* Throws exceptions on failure.
*
* @param string $url
* @param array $params
* @return object
*/
public static function getObject($url, $params=array())
{
common_log(LOG_INFO, 'QQQ: wtf? ' . $url);
$host = parse_url($url, PHP_URL_HOST);
if (substr($host, 0, 4) == 'www.') {
$host = substr($host, 4);
}
// Blacklist: systems with no oEmbed API of their own, which are
// either missing from or broken on oohembed.com's proxy.
// we know how to look data up in another way...
if (array_key_exists($host, self::$functionMap)) {
$func = self::$functionMap[$host];
return call_user_func($func, $url, $params);
}
// Whitelist: known API endpoints for sites that don't provide discovery...
if (array_key_exists($host, self::$apiMap)) {
$api = self::$apiMap[$host];
common_log(LOG_INFO, 'QQQ: going to: ' . $api);
} else {
$api = false;
common_log(LOG_INFO, 'QQQ: no map for ' . $host);
}
return self::getObjectFrom($api, $url, $params);
}
/**
* Actually do an oEmbed lookup to a particular API endpoint,
* or to the autodiscovered target, or to oohembed.
*
* @param mixed $api string or false: 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())
{
$options = array();
if ($api) {
$options[Services_oEmbed::OPTION_API] = $api;
}
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;
}
}
// And.... let's go look it up!
return $oEmbed->getObject($params);
}
/**
* Using a local function for twitpic lookups, as oohembed's adapter
* doesn't return a valid result:
* http://code.google.com/p/oohembed/issues/detail?id=19
*
* This code fetches metadata from Twitpic's own API, and attempts
* to guess proper thumbnail size from the original's size.
*
* @todo respect maxwidth and maxheight params
*
* @param string $url
* @param array $params
* @return object
*/
static function twitPic($url, $params=array())
{
$matches = array();
if (preg_match('!twitpic\.com/(\w+)!', $url, $matches)) {
$id = $matches[1];
} else {
throw new Exception("Invalid twitpic URL");
}
// Grab metadata from twitpic's API...
// http://dev.twitpic.com/docs/2/media_show
$data = self::json('http://api.twitpic.com/2/media/show.json',
array('id' => $id));
$oembed = (object)array('type' => 'photo',
'url' => 'http://twitpic.com/show/full/' . $data->short_id,
'width' => $data->width,
'height' => $data->height);
if (!empty($data->message)) {
$oembed->title = $data->message;
}
// Thumbnail is cropped and scaled to 150x150 box:
// http://dev.twitpic.com/docs/thumbnails/
$thumbSize = 150;
$oembed->thumbnail_url = 'http://twitpic.com/show/thumb/' . $data->short_id;
$oembed->thumbnail_width = $thumbSize;
$oembed->thumbnail_height = $thumbSize;
return $oembed;
}
/**
* Fetch some URL and return JSON data.
*
* @param string $url
* @param array $params query-string params
* @return object
*/
static protected function json($url, $params=array())
{
$data = self::http($url, $params);
return json_decode($data);
}
/**
* Hit some web API and return data on success.
* @param string $url
* @param array $params
* @return string
*/
static protected function http($url, $params=array())
{
$client = HTTPClient::start();
if ($params) {
$query = http_build_query($params, null, '&');
if (strpos($url, '?') === false) {
$url .= '?' . $query;
} else {
$url .= '&' . $query;
}
}
$response = $client->get($url);
if ($response->isOk()) {
return $response->getBody();
} else {
throw new Exception('Bad HTTP response code: ' . $response->getStatus());
}
}
}
class Services_oEmbed_Tweaked extends Services_oEmbed
{
protected function discover($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())
{
$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);
}
}