gnu-social/extlib/Services/oEmbed.php

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<?php
/**
* An interface for oEmbed consumption
*
* PHP version 5.1.0+
*
* Copyright (c) 2008, Digg.com, Inc.
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Digg.com, Inc. nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* @category Services
* @package Services_oEmbed
* @author Joe Stump <joe@joestump.net>
* @copyright 2008 Digg.com, Inc.
* @license http://tinyurl.com/42zef New BSD License
* @version SVN: @version@
* @link http://code.google.com/p/digg
* @link http://oembed.com
*/
require_once 'Validate.php';
require_once 'Net/URL2.php';
require_once 'HTTP/Request.php';
require_once 'Services/oEmbed/Exception.php';
require_once 'Services/oEmbed/Exception/NoSupport.php';
require_once 'Services/oEmbed/Object.php';
/**
* Base class for consuming oEmbed objects
*
* <code>
* <?php
*
* require_once 'Services/oEmbed.php';
*
* // The URL that we'd like to find out more information about.
* $url = 'http://flickr.com/photos/joestump/2848795611/';
*
* // The oEmbed API URI. Not all providers support discovery yet so we're
* // explicitly providing one here. If one is not provided Services_oEmbed
* // attempts to discover it. If none is found an exception is thrown.
* $oEmbed = new Services_oEmbed($url, array(
* Services_oEmbed::OPTION_API => 'http://www.flickr.com/services/oembed/'
* ));
* $object = $oEmbed->getObject();
*
* // All of the objects have somewhat sane __toString() methods that allow
* // you to output them directly.
* echo (string)$object;
*
* ?>
* </code>
*
* @category Services
* @package Services_oEmbed
* @author Joe Stump <joe@joestump.net>
* @copyright 2008 Digg.com, Inc.
* @license http://tinyurl.com/42zef New BSD License
* @version Release: @version@
* @link http://code.google.com/p/digg
* @link http://oembed.com
*/
class Services_oEmbed
{
/**
* HTTP timeout in seconds
*
* All HTTP requests made by Services_oEmbed will respect this timeout.
* This can be passed to {@link Services_oEmbed::setOption()} or to the
* options parameter in {@link Services_oEmbed::__construct()}.
*
* @var string OPTION_TIMEOUT Timeout in seconds
*/
const OPTION_TIMEOUT = 'http_timeout';
/**
* HTTP User-Agent
*
* All HTTP requests made by Services_oEmbed will be sent with the
* string set by this option.
*
* @var string OPTION_USER_AGENT The HTTP User-Agent string
*/
const OPTION_USER_AGENT = 'http_user_agent';
/**
* The API's URI
*
* If the API is known ahead of time this option can be used to explicitly
* set it. If not present then the API is attempted to be discovered
* through the auto-discovery mechanism.
*
* @var string OPTION_API
*/
const OPTION_API = 'oembed_api';
/**
* Options for oEmbed requests
*
* @var array $options The options for making requests
*/
protected $options = array(
self::OPTION_TIMEOUT => 3,
self::OPTION_API => null,
self::OPTION_USER_AGENT => 'Services_oEmbed 0.1.0'
);
/**
* URL of object to get embed information for
*
* @var object $url {@link Net_URL2} instance of URL of object
*/
protected $url = null;
/**
* Constructor
*
* @param string $url The URL to fetch an oEmbed for
* @param array $options A list of options for the oEmbed lookup
*
* @throws {@link Services_oEmbed_Exception} if the $url is invalid
* @throws {@link Services_oEmbed_Exception} when no valid API is found
* @return void
*/
public function __construct($url, array $options = array())
{
if (Validate::uri($url)) {
$this->url = new Net_URL2($url);
} else {
throw new Services_oEmbed_Exception('URL is invalid');
}
if (count($options)) {
foreach ($options as $key => $val) {
$this->setOption($key, $val);
}
}
if ($this->options[self::OPTION_API] === null) {
$this->options[self::OPTION_API] = $this->discover($url);
}
}
/**
* Set an option for the oEmbed request
*
* @param mixed $option The option name
* @param mixed $value The option value
*
* @see Services_oEmbed::OPTION_API, Services_oEmbed::OPTION_TIMEOUT
* @throws {@link Services_oEmbed_Exception} on invalid option
* @access public
* @return void
*/
public function setOption($option, $value)
{
switch ($option) {
case self::OPTION_API:
case self::OPTION_TIMEOUT:
break;
default:
throw new Services_oEmbed_Exception(
'Invalid option "' . $option . '"'
);
}
$func = '_set_' . $option;
if (method_exists($this, $func)) {
$this->options[$option] = $this->$func($value);
} else {
$this->options[$option] = $value;
}
}
/**
* Set the API option
*
* @param string $value The API's URI
*
* @throws {@link Services_oEmbed_Exception} on invalid API URI
* @see Validate::uri()
* @return string
*/
protected function _set_oembed_api($value)
{
if (!Validate::uri($value)) {
throw new Services_oEmbed_Exception(
'API URI provided is invalid'
);
}
return $value;
}
/**
* Get the oEmbed response
*
* @param array $params Optional parameters for
*
* @throws {@link Services_oEmbed_Exception} on cURL errors
* @throws {@link Services_oEmbed_Exception} on HTTP errors
* @throws {@link Services_oEmbed_Exception} when result is not parsable
* @return object The oEmbed response as an object
*/
public function getObject(array $params = array())
{
$params['url'] = $this->url->getURL();
if (!isset($params['format'])) {
$params['format'] = 'json';
}
$sets = array();
foreach ($params as $var => $val) {
$sets[] = $var . '=' . urlencode($val);
}
$url = $this->options[self::OPTION_API] . '?' . implode('&', $sets);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $this->options[self::OPTION_TIMEOUT]);
$result = curl_exec($ch);
if (curl_errno($ch)) {
throw new Services_oEmbed_Exception(
curl_error($ch), curl_errno($ch)
);
}
$code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
if (substr($code, 0, 1) != '2') {
throw new Services_oEmbed_Exception('Non-200 code returned');
}
curl_close($ch);
switch ($params['format']) {
case 'json':
$res = json_decode($result);
if (!is_object($res)) {
throw new Services_oEmbed_Exception(
'Could not parse JSON response'
);
}
break;
case 'xml':
libxml_use_internal_errors(true);
$res = simplexml_load_string($result);
if (!$res instanceof SimpleXMLElement) {
$errors = libxml_get_errors();
$err = array_shift($errors);
libxml_clear_errors();
libxml_use_internal_errors(false);
throw new Services_oEmbed_Exception(
$err->message, $error->code
);
}
break;
}
return Services_oEmbed_Object::factory($res);
}
/**
* Discover an oEmbed API
*
* @param string $url The URL to attempt to discover oEmbed for
*
* @throws {@link Services_oEmbed_Exception} if the $url is invalid
* @return string The oEmbed API endpoint discovered
*/
protected function discover($url)
{
$body = $this->sendRequest($url);
// Find all <link /> tags that have a valid oembed type set. We then
// extract the href attribute for each type.
$regexp = '#<link([^>]*)type="' .
'(application/json|text/xml)\+oembed"([^>]*)>#i';
$m = $ret = array();
if (!preg_match_all($regexp, $body, $m)) {
throw new Services_oEmbed_Exception_NoSupport(
'No valid oEmbed links found on page'
);
}
foreach ($m[0] as $i => $link) {
$h = array();
if (preg_match('/href="([^"]+)"/i', $link, $h)) {
$ret[$m[2][$i]] = $h[1];
}
}
return (isset($ret['application/json']) ? $ret['application/json'] : array_pop($ret));
}
/**
* Send a GET request to the provider
*
* @param mixed $url The URL to send the request to
*
* @throws {@link Services_oEmbed_Exception} on HTTP errors
* @return string The contents of the response
*/
private function sendRequest($url)
{
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $this->options[self::OPTION_TIMEOUT]);
curl_setopt($ch, CURLOPT_USERAGENT, $this->options[self::OPTION_USER_AGENT]);
$result = curl_exec($ch);
if (curl_errno($ch)) {
throw new Services_oEmbed_Exception(
curl_error($ch), curl_errno($ch)
);
}
$code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
if (substr($code, 0, 1) != '2') {
throw new Services_oEmbed_Exception('Non-200 code returned');
}
return $result;
}
}
?>