<?php
/**
* Class Minify_JS_ClosureCompiler
* @package Minify
*/
/**
* Minify Javascript using Google's Closure Compiler API
*
* @link http://code.google.com/closure/compiler/
* @package Minify
* @author Stephen Clay <steve@mrclay.org>
*
* @todo can use a stream wrapper to unit test this?
*/
class Minify_JS_ClosureCompiler
{
/**
* @var string The option key for the maximum POST byte size
*/
const OPTION_MAX_BYTES = 'maxBytes';
/**
* @var string The option key for additional params. @see __construct
*/
const OPTION_ADDITIONAL_OPTIONS = 'additionalParams';
/**
* @var string The option key for the fallback Minifier
*/
const OPTION_FALLBACK_FUNCTION = 'fallbackFunc';
/**
* @var string The option key for the service URL
*/
const OPTION_COMPILER_URL = 'compilerUrl';
/**
* @var int The default maximum POST byte size according to https://developers.google.com/closure/compiler/docs/api-ref
*/
const DEFAULT_MAX_BYTES = 200000;
/**
* @var string[] $DEFAULT_OPTIONS The default options to pass to the compiler service
*
* @note This would be a constant if PHP allowed it
*/
private static $DEFAULT_OPTIONS = array(
'output_format' => 'text',
'compilation_level' => 'SIMPLE_OPTIMIZATIONS'
);
/**
* @var string $url URL of compiler server. defaults to Google's
*/
protected $serviceUrl = 'https://closure-compiler.appspot.com/compile';
/**
* @var int $maxBytes The maximum JS size that can be sent to the compiler server in bytes
*/
protected $maxBytes = self::DEFAULT_MAX_BYTES;
/**
* @var string[] $additionalOptions Additional options to pass to the compiler service
*/
protected $additionalOptions = array();
/**
* @var callable Function to minify JS if service fails. Default is JSMin
*/
protected $fallbackMinifier = array('JSMin\\JSMin', 'minify');
/**
* Minify JavaScript code via HTTP request to a Closure Compiler API
*
* @param string $js input code
* @param array $options Options passed to __construct(). @see __construct
*
* @return string
*/
public static function minify($js, array $options = array())
{
$obj = new self($options);
return $obj->min($js);
}
/**
* @param array $options Options with keys available below:
*
* fallbackFunc : (callable) function to minify if service unavailable. Default is JSMin.
*
* compilerUrl : (string) URL to closure compiler server
*
* maxBytes : (int) The maximum amount of bytes to be sent as js_code in the POST request.
* Defaults to 200000.
*
* additionalParams : (string[]) Additional parameters to pass to the compiler server. Can be anything named
* in https://developers.google.com/closure/compiler/docs/api-ref except for js_code and
* output_info
*/
public function __construct(array $options = array())
{
if (isset($options[self::OPTION_FALLBACK_FUNCTION])) {
$this->fallbackMinifier = $options[self::OPTION_FALLBACK_FUNCTION];
}
if (isset($options[self::OPTION_COMPILER_URL])) {
$this->serviceUrl = $options[self::OPTION_COMPILER_URL];
}
if (isset($options[self::OPTION_ADDITIONAL_OPTIONS]) && is_array($options[self::OPTION_ADDITIONAL_OPTIONS])) {
$this->additionalOptions = $options[self::OPTION_ADDITIONAL_OPTIONS];
}
if (isset($options[self::OPTION_MAX_BYTES])) {
$this->maxBytes = (int) $options[self::OPTION_MAX_BYTES];
}
}
/**
* Call the service to perform the minification
*
* @param string $js JavaScript code
* @return string
* @throws Minify_JS_ClosureCompiler_Exception
*/
public function min($js)
{
$postBody = $this->buildPostBody($js);
if ($this->maxBytes > 0) {
$bytes = (function_exists('mb_strlen') && ((int)ini_get('mbstring.func_overload') & 2))
? mb_strlen($postBody, '8bit')
: strlen($postBody);
if ($bytes > $this->maxBytes) {
throw new Minify_JS_ClosureCompiler_Exception(
'POST content larger than ' . $this->maxBytes . ' bytes'
);
}
}
$response = $this->getResponse($postBody);
if (preg_match('/^Error\(\d\d?\):/', $response)) {
if (is_callable($this->fallbackMinifier)) {
// use fallback
$response = "/* Received errors from Closure Compiler API:\n$response"
. "\n(Using fallback minifier)\n*/\n";
$response .= call_user_func($this->fallbackMinifier, $js);
} else {
throw new Minify_JS_ClosureCompiler_Exception($response);
}
}
if ($response === '') {
$errors = $this->getResponse($this->buildPostBody($js, true));
throw new Minify_JS_ClosureCompiler_Exception($errors);
}
return $response;
}
/**
* Get the response for a given POST body
*
* @param string $postBody
* @return string
* @throws Minify_JS_ClosureCompiler_Exception
*/
protected function getResponse($postBody)
{
$allowUrlFopen = preg_match('/1|yes|on|true/i', ini_get('allow_url_fopen'));
if ($allowUrlFopen) {
$contents = file_get_contents($this->serviceUrl, false, stream_context_create(array(
'http' => array(
'method' => 'POST',
'compilation_level' => 'SIMPLE',
'output_format' => 'text',
'output_info' => 'compiled_code',
'header' => "Content-type: application/x-www-form-urlencoded\r\nConnection: close\r\n",
'content' => $postBody,
'max_redirects' => 0,
'timeout' => 15,
)
)));
} elseif (defined('CURLOPT_POST')) {
$ch = curl_init($this->serviceUrl);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: application/x-www-form-urlencoded'));
curl_setopt($ch, CURLOPT_POSTFIELDS, $postBody);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 15);
$contents = curl_exec($ch);
curl_close($ch);
} else {
throw new Minify_JS_ClosureCompiler_Exception(
"Could not make HTTP request: allow_url_open is false and cURL not available"
);
}
if (false === $contents) {
throw new Minify_JS_ClosureCompiler_Exception(
"No HTTP response from server"
);
}
return trim($contents);
}
/**
* Build a POST request body
*
* @param string $js JavaScript code
* @param bool $returnErrors
* @return string
*/
protected function buildPostBody($js, $returnErrors = false)
{
return http_build_query(
array_merge(
self::$DEFAULT_OPTIONS,
$this->additionalOptions,
array(
'js_code' => $js,
'output_info' => ($returnErrors ? 'errors' : 'compiled_code')
)
),
null,
'&'
);
}
}
class Minify_JS_ClosureCompiler_Exception extends Exception
{
}
