fixes #4373, #1640

LEGALNOTICE

@@ -114,16 +114,6 @@ THIRD-PARTY COMPONENTS AND LIBRARIES
 	Notes:
 	- reference implementation
 
-	Name:  cssmin
-	Link:  http://code.google.com/p/cssmin/
-	License:  MIT
-
-	Name:  jsmin
-	Link:  http://code.google.com/p/jsmin-php/
-	License:  MIT
-	Notes:
-	- contains additional clause "The Software shall be used for Good, not Evil."
-
 	Name:  sparkline
 	Link:  https//sourceforge.net/projects/sparkline/
 	License:  Dual-licensed: New BSD or GPL v2

composer.json

@@ -22,6 +22,7 @@
         "php": ">=5.3.0",
         "twig/twig": "1.*",
         "leafo/lessphp": "0.3.*",
-        "symfony/console": ">=v2.3.5"
+        "symfony/console": ">=v2.3.5",
+        "tedivm/jshrink": "v0.5.1"
     }
 }

core/AssetManager/UIAsset.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+use Exception;
+
+abstract class UIAsset
+{
+    abstract public function validateFile();
+
+    /**
+     * @return string
+     */
+    abstract public function getAbsoluteLocation();
+
+    /**
+     * @return string
+     */
+    abstract public function getRelativeLocation();
+
+    /**
+     * @return string
+     */
+    abstract public function getBaseDirectory();
+
+    /**
+     * Removes the previous file if it exists.
+     * Also tries to remove compressed version of the file.
+     *
+     * @see ProxyStaticFile::serveStaticFile(serveFile
+     * @throws Exception if the file couldn't be deleted
+     */
+    abstract public function delete();
+
+    /**
+     * @param string $content
+     * @throws \Exception
+     */
+    abstract public function writeContent($content);
+
+    /**
+     * @return string
+     */
+    abstract public function getContent();
+
+    /**
+     * @return boolean
+     */
+    abstract public function exists();
+
+    /**
+     * @return int
+     */
+    abstract public function getModificationDate();
+}

core/AssetManager/UIAsset/InMemoryUIAsset.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAsset;
+
+use Exception;
+use Piwik\AssetManager\UIAsset;
+
+class InMemoryUIAsset extends UIAsset
+{
+    private $content;
+
+    public function validateFile()
+    {
+        return;
+    }
+
+    public function getAbsoluteLocation()
+    {
+        throw new Exception('invalid operation');
+    }
+
+    public function getRelativeLocation()
+    {
+        throw new Exception('invalid operation');
+    }
+
+    public function getBaseDirectory()
+    {
+        throw new Exception('invalid operation');
+    }
+
+    public function delete()
+    {
+        $this->content = null;
+    }
+
+    public function exists()
+    {
+        return false;
+    }
+
+
+    public function writeContent($content)
+    {
+        $this->content = $content;
+    }
+
+    public function getContent()
+    {
+        return $this->content;
+    }
+
+    public function getModificationDate()
+    {
+        throw new Exception('invalid operation');
+    }
+}

core/AssetManager/UIAsset/OnDiskUIAsset.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAsset;
+
+use Exception;
+use Piwik\AssetManager\UIAsset;
+
+class OnDiskUIAsset extends UIAsset
+{
+    /**
+     * @var string
+     */
+    private $baseDirectory;
+
+    /**
+     * @var string
+     */
+    private $relativeLocation;
+
+    /**
+     * @param string $baseDirectory
+     * @param string $fileLocation
+     */
+    function __construct($baseDirectory, $fileLocation)
+    {
+        $this->baseDirectory = $baseDirectory;
+        $this->relativeLocation = $fileLocation;
+    }
+
+    public function getAbsoluteLocation()
+    {
+        return $this->baseDirectory . '/' . $this->relativeLocation;
+    }
+
+    public function getRelativeLocation()
+    {
+        return $this->relativeLocation;
+    }
+
+    public function getBaseDirectory()
+    {
+        return $this->baseDirectory;
+    }
+
+    public function validateFile()
+    {
+        if (!$this->assetIsReadable())
+            throw new Exception("The ui asset with 'href' = " . $this->getAbsoluteLocation() . " is not readable");
+    }
+
+    public function delete()
+    {
+        if ($this->exists()) {
+
+            if (!unlink($this->getAbsoluteLocation()))
+                throw new Exception("Unable to delete merged file : " . $this->getAbsoluteLocation() . ". Please delete the file and refresh");
+
+            // try to remove compressed version of the merged file.
+            @unlink($this->getAbsoluteLocation() . ".deflate");
+            @unlink($this->getAbsoluteLocation() . ".gz");
+        }
+    }
+
+    /**
+     * @param string $content
+     * @throws \Exception
+     */
+    public function writeContent($content)
+    {
+        $this->delete();
+
+        $newFile = @fopen($this->getAbsoluteLocation(), "w");
+
+        if (!$newFile)
+            throw new Exception ("The file : " . $newFile . " can not be opened in write mode.");
+
+        fwrite($newFile, $content);
+
+        fclose($newFile);
+    }
+
+    /**
+     * @return string
+     */
+    public function getContent()
+    {
+        return file_get_contents($this->getAbsoluteLocation());
+    }
+
+    public function exists()
+    {
+        return $this->assetIsReadable();
+    }
+
+    /**
+     * @return boolean
+     */
+    private function assetIsReadable()
+    {
+        return is_readable($this->getAbsoluteLocation());
+    }
+
+    public function getModificationDate()
+    {
+        return filemtime($this->getAbsoluteLocation());
+    }
+}

core/AssetManager/UIAssetCacheBuster.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @method static \Piwik\AssetManager\UIAssetCacheBuster getInstance()
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+use Piwik\Plugin\Manager;
+use Piwik\SettingsPiwik;
+use Piwik\Singleton;
+use Piwik\Version;
+
+class UIAssetCacheBuster extends Singleton
+{
+    /**
+     * Cache buster based on
+     *  - Piwik version
+     *  - Loaded plugins
+     *  - Super user salt
+     *  - Latest
+     *
+     * @param string[] $pluginNames
+     * @return string
+     */
+    public function piwikVersionBasedCacheBuster($pluginNames = false)
+    {
+        $currentGitHash = @file_get_contents(PIWIK_INCLUDE_PATH . '/.git/refs/heads/master');
+        $pluginList = md5(implode(",", !$pluginNames ? Manager::getInstance()->getLoadedPluginsName() : $pluginNames));
+        $cacheBuster = md5(SettingsPiwik::getSalt() . $pluginList . PHP_VERSION . Version::VERSION . trim($currentGitHash));
+        return $cacheBuster;
+    }
+
+    /**
+     * @param string $content
+     * @return string
+     */
+    public function md5BasedCacheBuster($content)
+    {
+        return md5($content);
+    }
+}

core/AssetManager/UIAssetCatalog.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+class UIAssetCatalog
+{
+    /**
+     * @var UIAsset[]
+     */
+    private $uiAssets = array();
+
+    /**
+     * @var UIAssetCatalogSorter
+     */
+    private $catalogSorter;
+
+    /**
+     * @var string
+     */
+    private $concatenatedAssets;
+
+    /**
+     * @param UIAssetCatalogSorter $catalogSorter
+     */
+    function __construct($catalogSorter)
+    {
+        $this->catalogSorter = $catalogSorter;
+    }
+
+    /**
+     * @param UIAsset $uiAsset
+     */
+    public function addUIAsset($uiAsset)
+    {
+        if(!$this->assetAlreadyInCatalog($uiAsset)) {
+
+            $this->uiAssets[] = $uiAsset;
+            $this->resetConcatenatedAssets();
+        }
+    }
+
+    /**
+     * @return UIAsset[]
+     */
+    public function getAssets()
+    {
+        return $this->uiAssets;
+    }
+
+    /**
+     * @return UIAssetCatalog
+     */
+    public function getSortedCatalog()
+    {
+        return $this->catalogSorter->sortUIAssetCatalog($this);
+    }
+
+    private function resetConcatenatedAssets()
+    {
+        $this->concatenatedAssets = null;
+    }
+
+    /**
+     * @param UIAsset $uiAsset
+     * @return boolean
+     */
+    private function assetAlreadyInCatalog($uiAsset)
+    {
+        foreach($this->uiAssets as $existingAsset)
+            if($uiAsset->getAbsoluteLocation() == $existingAsset->getAbsoluteLocation())
+                return true;
+
+        return false;
+    }
+}

core/AssetManager/UIAssetCatalogSorter.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+class UIAssetCatalogSorter
+{
+    /**
+     * @var string[]
+     */
+    private $priorityOrder;
+
+    /**
+     * @param string[] $priorityOrder
+     */
+    function __construct($priorityOrder)
+    {
+        $this->priorityOrder = $priorityOrder;
+    }
+
+    /**
+     * @param UIAssetCatalog $uiAssetCatalog
+     * @return UIAssetCatalog
+     */
+    public function sortUIAssetCatalog($uiAssetCatalog)
+    {
+        $sortedCatalog = new UIAssetCatalog($this);
+        foreach ($this->priorityOrder as $filePattern) {
+
+            $assetsMatchingPattern = array_filter($uiAssetCatalog->getAssets(), function($uiAsset) use ($filePattern)  {
+                return preg_match('~^' . $filePattern . '~', $uiAsset->getRelativeLocation());
+            });
+
+            foreach($assetsMatchingPattern as $assetMatchingPattern) {
+                $sortedCatalog->addUIAsset($assetMatchingPattern);
+            }
+        }
+
+        $this->addUnmatchedAssets($uiAssetCatalog, $sortedCatalog);
+
+        return $sortedCatalog;
+    }
+
+    /**
+     * @param UIAssetCatalog $uiAssetCatalog
+     * @param UIAssetCatalog $sortedCatalog
+     */
+    private function addUnmatchedAssets($uiAssetCatalog, $sortedCatalog)
+    {
+        foreach ($uiAssetCatalog->getAssets() as $uiAsset) {
+            $sortedCatalog->addUIAsset($uiAsset);
+        }
+    }
+}

core/AssetManager/UIAssetFetcher.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+use Piwik\AssetManager\UIAsset\OnDiskUIAsset;
+use Piwik\Theme;
+
+abstract class UIAssetFetcher
+{
+    /**
+     * @var UIAssetCatalog
+     */
+    protected $catalog;
+
+    /**
+     * @var string[]
+     */
+    protected $fileLocations = array();
+
+    /**
+     * @var string[]
+     */
+    protected $plugins;
+
+    /**
+     * @var Theme
+     */
+    private $theme;
+
+    /**
+     * @param string[] $plugins
+     * @param Theme $theme
+     */
+    function __construct($plugins, $theme)
+    {
+        $this->plugins = $plugins;
+        $this->theme = $theme;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getPlugins()
+    {
+        return $this->plugins;
+    }
+
+    /**
+     * $return UIAssetCatalog
+     */
+    public function getCatalog()
+    {
+        if($this->catalog == null)
+            $this->createCatalog();
+
+        return $this->catalog;
+    }
+
+    abstract protected function retrieveFileLocations();
+
+    /**
+     * @return string[]
+     */
+    abstract protected function getPriorityOrder();
+
+    private function createCatalog()
+    {
+        $this->retrieveFileLocations();
+
+        $this->initCatalog();
+
+        $this->populateCatalog();
+
+        $this->sortCatalog();
+    }
+
+    private function initCatalog()
+    {
+        $catalogSorter = new UIAssetCatalogSorter($this->getPriorityOrder());
+        $this->catalog = new UIAssetCatalog($catalogSorter);
+    }
+
+    private function populateCatalog()
+    {
+        foreach ($this->fileLocations as $fileLocation) {
+
+            $newUIAsset = new OnDiskUIAsset($this->getBaseDirectory(), $fileLocation);
+            $this->catalog->addUIAsset($newUIAsset);
+        }
+    }
+
+    private function sortCatalog()
+    {
+        $this->catalog = $this->catalog->getSortedCatalog();
+    }
+
+    /**
+     * @return string
+     */
+    private function getBaseDirectory()
+    {
+        // served by web server directly, so must be a public path
+        return PIWIK_USER_PATH;
+    }
+
+    /**
+     * @return Theme
+     */
+    public function getTheme()
+    {
+        return $this->theme;
+    }
+}

core/AssetManager/UIAssetFetcher/JScriptUIAssetFetcher.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAssetFetcher;
+
+use Piwik\AssetManager\UIAssetFetcher;
+use Piwik\Piwik;
+use string;
+
+class JScriptUIAssetFetcher extends UIAssetFetcher
+{
+
+    protected function retrieveFileLocations()
+    {
+
+        if(!empty($this->plugins)) {
+
+            /**
+             * Triggered when gathering the list of all JavaScript files needed by Piwik
+             * and its plugins.
+             *
+             * Plugins that have their own JavaScript should use this event to make those
+             * files load in the browser.
+             *
+             * JavaScript files should be placed within a **javascripts** subdirectory in your
+             * plugin's root directory.
+             *
+             * _Note: While you are developing your plugin you should enable the config setting
+             * `[Debug] disable_merged_assets` so JavaScript files will be reloaded immediately
+             * after every change._
+             *
+             * **Example**
+             *
+             *     public function getJsFiles(&$jsFiles)
+             *     {
+             *         $jsFiles[] = "plugins/MyPlugin/javascripts/myfile.js";
+             *         $jsFiles[] = "plugins/MyPlugin/javascripts/anotherone.js";
+             *     }
+             *
+             * @param string[] $jsFiles The JavaScript files to load.
+             */
+             Piwik::postEvent('AssetManager.getJavaScriptFiles', array(&$this->fileLocations), null, $this->plugins);
+        }
+
+        $this->addThemeFiles();
+    }
+
+    protected function addThemeFiles()
+    {
+        if(in_array($this->getTheme()->getThemeName(), $this->plugins)) {
+
+            $jsInThemes = $this->getTheme()->getJavaScriptFiles();
+
+            if(!empty($jsInThemes)) {
+
+                foreach($jsInThemes as $jsFile) {
+
+                    $this->fileLocations[] = $jsFile;
+                }
+            }
+        }
+    }
+
+    protected function getPriorityOrder()
+    {
+        return array(
+            'libs/jquery/jquery.js',
+            'libs/jquery/jquery-ui.js',
+            'libs/jquery/jquery.browser.js',
+            'libs/',
+            'plugins/Zeitgeist/javascripts/piwikHelper.js',
+            'plugins/Zeitgeist/javascripts/',
+            'plugins/CoreHome/javascripts/broadcast.js',
+            'plugins/',
+            'tests/',
+        );
+    }
+}

core/AssetManager/UIAssetFetcher/StaticUIAssetFetcher.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAssetFetcher;
+
+use Piwik\AssetManager\UIAssetFetcher;
+
+class StaticUIAssetFetcher extends UIAssetFetcher
+{
+    /**
+     * @var string[]
+     */
+    private $priorityOrder;
+
+    function __construct($fileLocations, $priorityOrder, $theme)
+    {
+        parent::__construct(array(), $theme);
+
+        $this->fileLocations = $fileLocations;
+        $this->priorityOrder = $priorityOrder;
+    }
+
+    protected function retrieveFileLocations()
+    {
+
+    }
+
+    protected function getPriorityOrder()
+    {
+        return $this->priorityOrder;
+    }
+}

core/AssetManager/UIAssetFetcher/StylesheetUIAssetFetcher.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAssetFetcher;
+
+use Piwik\AssetManager\UIAssetFetcher;
+use Piwik\Piwik;
+
+class StylesheetUIAssetFetcher extends UIAssetFetcher
+{
+    protected function getPriorityOrder()
+    {
+        return array(
+            'libs/',
+            'plugins/CoreHome/stylesheets/color_manager.css', // must be before other Piwik stylesheets
+            'plugins/Zeitgeist/stylesheets/base.less',
+            'plugins/Zeitgeist/stylesheets/',
+            'plugins/',
+            'plugins/Dashboard/stylesheets/dashboard.less',
+            'tests/',
+        );
+    }
+
+    protected function retrieveFileLocations()
+    {
+        /**
+         * Triggered when gathering the list of all stylesheets (CSS and LESS) needed by
+         * Piwik and its plugins.
+         *
+         * Plugins that have stylesheets should use this event to make those stylesheets
+         * load.
+         *
+         * Stylesheets should be placed within a **stylesheets** subdirectory in your plugin's
+         * root directory.
+         *
+         * _Note: While you are developing your plugin you should enable the config setting
+         * `[Debug] disable_merged_assets` so your stylesheets will be reloaded immediately
+         * after a change._
+         *
+         * **Example**
+         *
+         *     public function getStylesheetFiles(&$stylesheets)
+         *     {
+         *         $stylesheets[] = "plugins/MyPlugin/stylesheets/myfile.less";
+         *         $stylesheets[] = "plugins/MyPlugin/stylesheets/myotherfile.css";
+         *     }
+         *
+         * @param string[] &$stylesheets The list of stylesheet paths.
+         */
+        Piwik::postEvent('AssetManager.getStylesheetFiles', array(&$this->fileLocations));
+
+        $this->addThemeFiles();
+    }
+
+    protected function addThemeFiles()
+    {
+        $themeStylesheet = $this->getTheme()->getStylesheet();
+
+        if($themeStylesheet) {
+            $this->fileLocations[] = $themeStylesheet;
+        }
+    }
+}

core/AssetManager/UIAssetMerger.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+use Piwik\AssetManager\PiwikLessCompiler;
+use Piwik\AssetManager\UIAsset\StylesheetUIAsset;
+use Piwik\AssetManager;
+
+abstract class UIAssetMerger
+{
+    /**
+     * @var UIAssetFetcher
+     */
+    private $assetFetcher;
+
+    /**
+     * @var UIAsset
+     */
+    private $mergedAsset;
+
+    /**
+     * @var string
+     */
+    private $mergedContent;
+
+    /**
+     * @var UIAssetCacheBuster
+     */
+    protected $cacheBuster;
+
+    /**
+     * @param UIAsset $mergedAsset
+     * @param UIAssetFetcher $assetFetcher
+     * @param UIAssetCacheBuster $cacheBuster
+     */
+    function __construct($mergedAsset, $assetFetcher, $cacheBuster)
+    {
+        $this->mergedAsset = $mergedAsset;
+        $this->assetFetcher = $assetFetcher;
+        $this->cacheBuster = $cacheBuster;
+    }
+
+    public function generateFile()
+    {
+        if(!$this->shouldGenerate())
+            return;
+
+        $this->mergedContent = $this->getMergedAssets();
+
+        $this->postEvent($this->mergedContent);
+
+        $this->adjustPaths();
+
+        $this->addPreamble();
+
+        $this->writeContentToFile();
+    }
+
+    /**
+     * @return string
+     */
+    abstract protected function getMergedAssets();
+
+    /**
+     * @return string
+     */
+    abstract protected function generateCacheBuster();
+
+    /**
+     * @return string
+     */
+    abstract protected function getPreamble();
+
+    /**
+     * @return string
+     */
+    abstract protected function getFileSeparator();
+
+    /**
+     * @param UIAsset $uiAsset
+     * @return string
+     */
+    abstract protected function processFileContent($uiAsset);
+
+    /**
+     * @param string $mergedContent
+     */
+    abstract protected function postEvent(&$mergedContent);
+
+    protected function getConcatenatedAssets()
+    {
+        if(empty($this->mergedContent))
+            $this->concatenateAssets();
+
+        return $this->mergedContent;
+    }
+
+    private function concatenateAssets()
+    {
+        $mergedContent = '';
+
+        foreach ($this->getAssetCatalog()->getAssets() as $uiAsset) {
+
+            $uiAsset->validateFile();
+            $content = $this->processFileContent($uiAsset);
+
+            $mergedContent .= $this->getFileSeparator() . $content;
+        }
+
+        $this->mergedContent = $mergedContent;
+    }
+
+    /**
+     * @return string[]
+     */
+    protected function getPlugins()
+    {
+        return $this->assetFetcher->getPlugins();
+    }
+
+    /**
+     * @return UIAssetCatalog
+     */
+    protected function getAssetCatalog()
+    {
+        return $this->assetFetcher->getCatalog();
+    }
+
+    /**
+     * @return boolean
+     */
+    private function shouldGenerate()
+    {
+        if(!$this->mergedAsset->exists())
+            return true;
+
+        if($this->shouldCompareExistingVersion()) {
+
+            return !$this->isFileUpToDate();
+        }
+
+        return false;
+    }
+
+    /**
+     * @return boolean
+     */
+    private function isFileUpToDate()
+    {
+        $f = fopen($this->mergedAsset->getAbsoluteLocation(), 'r');
+        $firstLine = fgets($f);
+        fclose($f);
+
+        if (!empty($firstLine) && trim($firstLine) == trim($this->getCacheBusterValue())) {
+            return true;
+        }
+
+        // Some CSS file in the merge, has changed since last merged asset was generated
+        // Note: we do not detect changes in @import'ed LESS files
+        return false;
+    }
+
+    /**
+     * @return boolean
+     */
+    private function isMergedAssetsDisabled()
+    {
+        return AssetManager::getInstance()->isMergedAssetsDisabled();
+    }
+
+    private function adjustPaths()
+    {
+        $this->mergedContent = $this->assetFetcher->getTheme()->rewriteAssetsPathToTheme($this->mergedContent);
+    }
+
+    private function writeContentToFile()
+    {
+        $this->mergedAsset->writeContent($this->mergedContent);
+    }
+
+    /**
+     * @return string
+     */
+    protected function getCacheBusterValue()
+    {
+        if(empty($this->cacheBusterValue))
+            $this->cacheBusterValue = $this->generateCacheBuster();
+
+        return $this->cacheBusterValue;
+    }
+
+    private function addPreamble()
+    {
+        $this->mergedContent = $this->getPreamble() . $this->mergedContent;
+    }
+
+    /**
+     * @return boolean
+     */
+    private function shouldCompareExistingVersion()
+    {
+        return $this->isMergedAssetsDisabled();
+    }
+}

core/AssetManager/UIAssetMerger/JScriptUIAssetMerger.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAssetMerger;
+
+use Piwik\AssetManager\UIAsset;
+use Piwik\AssetManager\UIAssetCacheBuster;
+use Piwik\AssetManager\UIAssetFetcher\JScriptUIAssetFetcher;
+use Piwik\AssetManager\UIAssetMerger;
+use Piwik\AssetManager;
+use Piwik\AssetManager\UIAssetMinifier;
+use Piwik\Piwik;
+
+class JScriptUIAssetMerger extends UIAssetMerger
+{
+    /**
+     * @var UIAssetMinifier
+     */
+    private $assetMinifier;
+
+    /**
+     * @param UIAsset $mergedAsset
+     * @param JScriptUIAssetFetcher $assetFetcher
+     * @param UIAssetCacheBuster $cacheBuster
+     */
+    function __construct($mergedAsset, $assetFetcher, $cacheBuster)
+    {
+        parent::__construct($mergedAsset, $assetFetcher, $cacheBuster);
+
+        $this->assetMinifier = UIAssetMinifier::getInstance();
+    }
+
+    protected function getMergedAssets()
+    {
+        $concatenatedAssets = $this->getConcatenatedAssets();
+
+        return str_replace("\n", "\r\n", $concatenatedAssets);
+    }
+
+    protected function generateCacheBuster()
+    {
+        $cacheBuster = $this->cacheBuster->piwikVersionBasedCacheBuster($this->getPlugins());
+        return "/* Piwik Javascript - cb=" . $cacheBuster . "*/\r\n";
+    }
+
+    protected function getPreamble()
+    {
+        return $this->getCacheBusterValue();
+    }
+
+    protected function postEvent(&$mergedContent)
+    {
+        $plugins = $this->getPlugins();
+
+        if(!empty($plugins)) {
+
+            /**
+             * Triggered after all the JavaScript files Piwik uses are minified and merged into a
+             * single file, but before the merged JavaScript is written to disk.
+             *
+             * Plugins can use this event to modify merged JavaScript or do something else
+             * with it.
+             *
+             * @param string $mergedContent The minified and merged JavaScript.
+             */
+            Piwik::postEvent('AssetManager.filterMergedJavaScripts', array(&$mergedContent), null, $plugins);
+        }
+    }
+
+    public function getFileSeparator()
+    {
+        return PHP_EOL;
+    }
+
+    protected function processFileContent($uiAsset)
+    {
+        $content = $uiAsset->getContent();
+
+        if (!$this->assetMinifier->isMinifiedJs($content))
+            $content = $this->assetMinifier->minifyJs($content);
+
+        return $content;
+    }
+}

core/AssetManager/UIAssetMerger/StylesheetUIAssetMerger.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+namespace Piwik\AssetManager\UIAssetMerger;
+
+use Exception;
+use Piwik\AssetManager\UIAsset;
+use Piwik\AssetManager\UIAssetMerger;
+use Piwik\Piwik;
+use lessc;
+
+class StylesheetUIAssetMerger extends UIAssetMerger
+{
+    /**
+     * @var lessc
+     */
+    private $lessCompiler;
+
+    function __construct($mergedAsset, $assetFetcher, $cacheBuster)
+    {
+        parent::__construct($mergedAsset, $assetFetcher, $cacheBuster);
+
+        $this->lessCompiler = self::getLessCompiler();
+    }
+
+    protected function getMergedAssets()
+    {
+        foreach($this->getAssetCatalog()->getAssets() as $uiAsset) {
+            $this->lessCompiler->addImportDir(dirname($uiAsset->getAbsoluteLocation()));
+        }
+
+        return $this->lessCompiler->compile($this->getConcatenatedAssets());
+    }
+
+    /**
+     * @return lessc
+     * @throws Exception
+     */
+    private static function getLessCompiler()
+    {
+        if (!class_exists("lessc")) {
+            throw new Exception("Less was added to composer during 2.0. ==> Execute this command to update composer packages: \$ php composer.phar install");
+        }
+        $less = new lessc();
+        return $less;
+    }
+
+    protected function generateCacheBuster()
+    {
+        $fileHash = $this->cacheBuster->md5BasedCacheBuster($this->getConcatenatedAssets());
+        return "/* compile_me_once=$fileHash */";
+    }
+
+    protected function getPreamble()
+    {
+        return $this->getCacheBusterValue() . "\n"
+        . "/* Piwik CSS file is compiled with Less. You may be interested in writing a custom Theme for Piwik! */\n";
+    }
+
+    protected function postEvent(&$mergedContent)
+    {
+        /**
+         * Triggered after all less stylesheets are compiled to CSS, minified and merged into
+         * one file, but before the generated CSS is written to disk.
+         *
+         * This event can be used to modify merged CSS.
+         *
+         * @param string $mergedContent The merged and minified CSS.
+         */
+        Piwik::postEvent('AssetManager.filterMergedStylesheets', array(&$mergedContent));
+    }
+
+    public function getFileSeparator()
+    {
+        return '';
+    }
+
+    protected function processFileContent($uiAsset)
+    {
+        return $this->rewriteCssPathsDirectives($uiAsset);
+    }
+
+    /**
+     * Rewrite css url directives
+     * - rewrites paths defined relatively to their css/less definition file
+     * - rewrite windows directory separator \\ to /
+     *
+     * @param UIAsset $uiAsset
+     * @return string
+     */
+    private function rewriteCssPathsDirectives($uiAsset)
+    {
+        static $rootDirectoryLength = null;
+        if (is_null($rootDirectoryLength)) {
+            $rootDirectoryLength = self::countDirectoriesInPathToRoot($uiAsset);
+        }
+
+        $baseDirectory = dirname($uiAsset->getRelativeLocation());
+        $content = preg_replace_callback(
+            "/(url\(['\"]?)([^'\")]*)/",
+            function ($matches) use ($rootDirectoryLength, $baseDirectory) {
+
+                $absolutePath = realpath(PIWIK_USER_PATH . "/$baseDirectory/" . $matches[2]);
+
+                if($absolutePath) {
+
+                    $relativePath = substr($absolutePath, $rootDirectoryLength);
+
+                    $relativePath = str_replace('\\', '/', $relativePath);
+
+                    return $matches[1] . $relativePath;
+
+                } else {
+                    return $matches[1] . $matches[2];
+                }
+            },
+            $uiAsset->getContent()
+        );
+        return $content;
+    }
+
+    /**
+     * @param UIAsset $uiAsset
+     * @return int
+     */
+    protected function countDirectoriesInPathToRoot($uiAsset)
+    {
+        $rootDirectory = realpath($uiAsset->getBaseDirectory());
+        if ($rootDirectory != '/' && substr_compare($rootDirectory, '/', -1)) {
+            $rootDirectory .= '/';
+        }
+        $rootDirectoryLen = strlen($rootDirectory);
+        return $rootDirectoryLen;
+    }
+}

core/AssetManager/UIAssetMinifier.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @method static \Piwik\AssetManager\UIAssetMinifier getInstance()
+ * @package Piwik
+ */
+namespace Piwik\AssetManager;
+
+use Exception;
+use Piwik\Singleton;
+use JShrink\Minifier;
+
+class UIAssetMinifier extends Singleton
+{
+    const MINIFIED_JS_RATIO = 100;
+
+    protected function __construct()
+    {
+        self::validateDependency();
+        parent::__construct();
+    }
+
+
+    /**
+     * Indicates if the provided JavaScript content has already been minified or not.
+     * The heuristic is based on a custom ratio : (size of file) / (number of lines).
+     * The threshold (100) has been found empirically on existing files :
+     * - the ratio never exceeds 50 for non-minified content and
+     * - it never goes under 150 for minified content.
+     *
+     * @param string $content Contents of the JavaScript file
+     * @return boolean
+     */
+    public function isMinifiedJs($content)
+    {
+        $lineCount = substr_count($content, "\n");
+        if ($lineCount == 0) {
+            return true;
+        }
+
+        $contentSize = strlen($content);
+
+        $ratio = $contentSize / $lineCount;
+
+        return $ratio > self::MINIFIED_JS_RATIO;
+    }
+
+    /**
+     * @param string $content
+     * @return string
+     */
+    public function minifyJs($content)
+    {
+        return Minifier::minify($content);
+    }
+
+    private static function validateDependency()
+    {
+        if (!class_exists("JShrink\Minifier"))
+            throw new Exception("JShrink dependency is managed using Composer.");
+    }
+}

core/Db/BatchInsert.php

@@ -61,7 +61,7 @@ class BatchInsert
      */
     public static function tableInsertBatch($tableName, $fields, $values, $throwException = false)
     {
-        $filePath = PIWIK_USER_PATH . '/' . AssetManager::MERGED_FILE_DIR . $tableName . '-' . Common::generateUniqId() . '.csv';
+        $filePath = PIWIK_USER_PATH . '/tmp/assets/' . $tableName . '-' . Common::generateUniqId() . '.csv';
         $filePath = SettingsPiwik::rewriteTmpPathWithHostname($filePath);
 
         if (Db::get()->hasBulkLoader()) {

core/Filesystem.php

@@ -24,9 +24,9 @@ class Filesystem
      * Called on Core install, update, plugin enable/disable
      * Will clear all cache that could be affected by the change in configuration being made
      */
-    public static function deleteAllCacheOnUpdate()
+    public static function deleteAllCacheOnUpdate($pluginName = false)
     {
-        AssetManager::removeMergedAssets();
+        AssetManager::getInstance()->removeMergedAssets($pluginName);
         View::clearCompiledTemplates();
         Cache::deleteTrackerCache();
     }

core/Plugin.php

@@ -262,7 +262,7 @@ class Plugin
      *
      * @return bool
      */
-    final public function isTheme()
+    public function isTheme()
     {
         $info = $this->getInformation();
         return !empty($info['theme']) && (bool)$info['theme'];