Add ClosureCompiler filter.

Lib/Filter/ClosureCompiler.php

@@ -0,0 +1,133 @@
+<?php
+
+App::uses('AssetFilter', 'AssetCompress.Lib');
+
+/**
+ * Google Closure Compiler API Filter
+ *
+ * Allows you to filter Javascript files through the Google Closure compiler API. The script
+ * needs to have web access to run.
+ *
+ * @package AssetCompress.Lib.Filter
+ */
+class ClosureCompiler extends AssetFilter {
+
+/**
+ * Defaults.
+ *
+ * @var array
+ */
+	protected $_defaults = array('compilation_level' => 'WHITESPACE_ONLY');
+
+/**
+ * Settings.
+ *
+ * NOTE: statistics and warnings are only used when in debug mode.
+ *
+ * - level (string) Defaults to WHITESPACE_ONLY. Values: SIMPLE_OPTIMIZATIONS, ADVANCED_OPTIMIZATIONS.
+ * - print (string) How to output the errors, statistics and/or warnings.
+ * - statistics (boolean) Defaults to FALSE.
+ * - warnings (mixed) Defaults to FALSE. Values: TRUE or QUIET, DEFAULT, VERBOSE.
+ *
+ * @var array
+ */
+	protected $_settings = array(
+		'level' => null,
+		'print' => "%s:\n%s\n",
+		'statistics' => false,
+		'warnings' => false
+	);
+
+/**
+ * Optional API parameters.
+ *
+ * - The `output_file_name` hasn't been included because AssetCompress is used for saving the minified javascript.
+ * - The `warning_level` is automatically handled in `self::$_settings`.
+ *
+ * @var array
+ * @see https://developers.google.com/closure/compiler/docs/api-ref
+ */
+	private $__params = array(
+		'js_externs',
+		'externs_url',
+		'exclude_default_externs',
+		'formatting',
+		'use_closure_library',
+		'language'
+	);
+
+/**
+ * {@inheritdoc}
+ */
+	public function output($filename, $content) {
+		$defaults = array('compilation_level' => $this->_settings['level']);
+
+		$errors = $this->_query($content, array('output_info' => 'errors'));
+		if (!empty($errors)) {
+			printf($this->_settings['print'], 'Errors', $errors);
+			exit;
+		}
+
+		$output = $this->_query($content, array('output_info' => 'compiled_code'));
+
+		if (!Configure::read('debug')) {
+			return $output;
+		}
+
+		foreach ($this->_settings as $setting => $value) {
+			if (!in_array($setting, array('warnings', 'statistics')) || true != $value) {
+				continue;
+			}
+
+			$args = array('output_info' => $setting);
+			if ('warnings' == $setting && in_array($value, array('QUIET', 'DEFAULT', 'VERBOSE'))) {
+				$args['warning_level'] = $value;
+			}
+
+			$$setting = $this->_query($content, $args);
+			printf($this->_settings['print'], ucfirst($setting), $$setting);
+		}
+
+		return $output;
+	}
+
+/**
+ * Query the Closure compiler API.
+ *
+ * @param string $content Javascript to compile.
+ * @param array $args API parameters.
+ * @throws Exception If curl triggers an error.
+ * @return string
+ */
+	protected function _query($content, $args = array()) {
+		$args = array_merge($this->_defaults, $args);
+		if (!empty($this->_settings['level'])) {
+			$args['compilation_level'] = $this->_settings['level'];
+		}
+
+		foreach ($this->_settings as $key => $val) {
+			if (in_array($key, $this->__params)) {
+				$args[$key] = $val;
+			}
+		}
+
+		$ch = curl_init();
+		curl_setopt_array($ch, array(
+			CURLOPT_URL => 'http://closure-compiler.appspot.com/compile',
+			CURLOPT_POST => 1,
+			CURLOPT_POSTFIELDS => 'js_code=' . urlencode($content) . '&' . http_build_query($args),
+			CURLOPT_RETURNTRANSFER =>  1,
+			CURLOPT_HEADER => 0,
+			CURLOPT_FOLLOWLOCATION => 0
+		));
+
+		$output = curl_exec($ch);
+
+		if (false === $output) {
+			throw new Exception('Curl error: ' . curl_error($ch));
+		}
+
+		curl_close($ch);
+		return $output;
+	}
+}