silverstripe-framework/oembed/Oembed.php
2012-05-24 17:00:22 +12:00

287 lines
7.1 KiB
PHP

<?php
/**
* Format of the Oembed config. Autodiscover allows discovery of all URLs.
* Endpoint set to true means autodiscovery for this specific provider is allowed
* (even if autodiscovery in general has been disabled).
*
* Oembed:
* providers:
* {pattern}:
* {endpoint}/true
* autodiscover:
* true/false
*/
class Oembed {
/**
* Gets the autodiscover setting from the config.
*/
public static function get_autodiscover() {
return Config::inst()->get('Oembed', 'autodiscover');
}
/**
* Gets providers from config.
*/
public static function get_providers() {
return Config::inst()->get('Oembed', 'providers');
}
/**
* Returns an endpoint (a base Oembed URL) from first matching provider.
*
* @param $url Human-readable URL.
* @returns string/bool URL of an endpoint, or false if no matching provider exists.
*/
protected static function find_endpoint($url) {
foreach(self::get_providers() as $scheme=>$endpoint) {
if(self::matches_scheme($url, $scheme)) {
return $endpoint;
}
}
return false;
}
/**
* Checks the URL if it matches against the scheme (pattern).
*
* @param $url Human-readable URL to be checked.
* @param $scheme Pattern to be matched against.
* @returns bool Whether the pattern matches or not.
*/
protected static function matches_scheme($url, $scheme) {
$urlInfo = parse_url($url);
$schemeInfo = parse_url($scheme);
foreach($schemeInfo as $k=>$v) {
if(!array_key_exists($k, $urlInfo)) {
return false;
}
if(strpos($v, '*') !== false) {
$v = preg_quote($v, '/');
$v = str_replace('\*', '.*', $v);
if($k == 'host') {
$v = str_replace('*\.', '*', $v);
}
if(!preg_match('/' . $v . '/', $urlInfo[$k])) {
return false;
}
} elseif(strcasecmp($urlInfo[$k], $v)) {
return false;
}
}
return true;
}
/**
* Performs a HTTP request to the URL and scans the response for resource links
* that mention oembed in their type.
*
* @param $url Human readable URL.
* @returns string/bool Oembed URL, or false.
*/
protected static function autodiscover_from_url($url) {
// Fetch the URL
$service = new RestfulService($url);
$body = $service->request();
if(!$body || $body->isError()) {
return false;
}
$body = $body->getBody();
// Look within the body for an oembed link.
if(preg_match_all('#<link[^>]+?(?:href=[\'"](.+?)[\'"][^>]+?)?type=["\']application/json\+oembed["\'](?:[^>]+?href=[\'"](.+?)[\'"])?#', $body, $matches, PREG_SET_ORDER)) {
$match = $matches[0];
if(!empty($match[1])) {
return html_entity_decode($match[1]);
}
if(!empty($match[2])) {
return html_entity_decode($match[2]);
}
}
return false;
}
/**
* Takes the human-readable URL of an embeddable resource and converts it into an
* Oembed_Result descriptor (which contains a full Oembed resource URL).
*
* @param $url Human-readable URL
* @param $type ?
* @param $options array Options to be used for constructing the resulting descriptor.
* @returns Oembed_Result/bool An Oembed descriptor, or false
*/
public static function get_oembed_from_url($url, $type = false, array $options = array()) {
// Find or build the Oembed URL.
$endpoint = self::find_endpoint($url);
$oembedUrl = false;
if(!$endpoint) {
if(self::get_autodiscover()) {
$oembedUrl = self::autodiscover_from_url($url);
}
} elseif($endpoint === true) {
$oembedUrl = self::autodiscover_from_url($url);
} else {
// Build the url manually - we gave all needed information.
$oembedUrl = Controller::join_links($endpoint, '?format=json&url=' . rawurlencode($url));
}
if($oembedUrl) {
// Inject the options into the Oembed URL.
if($options) {
if(isset($options['width']) && !isset($options['maxwidth'])) {
$options['maxwidth'] = $options['width'];
}
if(isset($options['height']) && !isset($options['maxheight'])) {
$options['maxheight'] = $options['height'];
}
$oembedUrl = Controller::join_links($oembedUrl, '?' . http_build_query($options, '', '&'));
}
return new Oembed_Result($oembedUrl, $url, $type, $options);
}
// No matching Oembed resource found.
return false;
}
public static function handle_shortcode($arguments, $url, $parser, $shortcode) {
if(isset($arguments['type'])) {
$type = $arguments['type'];
unset($arguments['type']);
} else {
$type = false;
}
$oembed = self::get_oembed_from_url($url, $type, $arguments);
if($oembed && $oembed->exists()) {
return $oembed->forTemplate();
} else {
return '<a href="' . $url . '">' . $url . '</a>';
}
}
}
class Oembed_Result extends ViewableData {
/**
* JSON data fetched from the Oembed URL.
* This data is accessed dynamically by getField and hasField.
*/
protected $data = false;
/**
* Human readable URL
*/
protected $origin = false;
/**
* ?
*/
protected $type = false;
/**
* Oembed URL
*/
protected $url;
/**
* Class to be injected into the resulting HTML element.
*/
protected $extraClass;
public static $casting = array(
'html' => 'HTMLText',
);
public function __construct($url, $origin = false, $type = false, array $options = array()) {
$this->url = $url;
$this->origin = $origin;
$this->type = $type;
if(isset($options['class'])) {
$this->extraClass = $options['class'];
}
parent::__construct();
}
public function getOembedURL() {
return $this->url;
}
/**
* Fetches the JSON data from the Oembed URL (cached).
* Only sets the internal variable.
*/
protected function loadData() {
if($this->data !== false) {
return;
}
// Fetch from Oembed URL
$service = new RestfulService($this->url);
$body = $service->request();
if(!$body || $body->isError()) {
$this->data = array();
return;
}
$body = $body->getBody();
$data = json_decode($body, true);
if(!$data) {
$data = array();
}
// Convert all keys to lowercase
$data = array_change_key_case($data, CASE_LOWER);
// Purge everything if the type does not match.
if($this->type && $this->type != $data['type']) {
$data = array();
}
$this->data = $data;
}
/**
* Wrap the check for looking into Oembed JSON within $this->data.
*/
public function hasField($field) {
$this->loadData();
return array_key_exists(strtolower($field), $this->data);
}
/**
* Wrap the field calls to fetch data from Oembed JSON (within $this->data)
*/
public function getField($field) {
$field = strtolower($field);
if($this->hasField($field)) {
return $this->data[$field];
}
}
public function forTemplate() {
$this->loadData();
switch($this->Type) {
case 'video':
case 'rich':
if($this->extraClass) {
return "<div class='$this->extraClass'>$this->HTML</div>";
} else {
return $this->HTML;
}
break;
case 'link':
return '<a class="' . $this->extraClass . '" href="' . $this->origin . '">' . $this->Title . '</a>';
break;
case 'photo':
return "<img src='$this->URL' width='$this->Width' height='$this->Height' class='$this->extraClass' />";
break;
}
}
public function exists() {
$this->loadData();
return count($this->data) > 0;
}
}