Added PEAR Services/oEmbed and its dependencies for multimedia integration.

1 files changed, 357 insertions, 0 deletions

diff --git a/extlib/Services/oEmbed.php b/extlib/Services/oEmbed.php
new file mode 100644
index 000000000..5d38ed883
--- /dev/null
+++ b/extlib/Services/oEmbed.php
@@ -0,0 +1,357 @@
+<?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();
+        } 
+    }
+
+    /**
+     * 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['json']) ? $ret['json'] : array_pop($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;
+    }
+}
+
+?>