Middleware for LESS CSS

Middleware/Less.php

@@ -0,0 +1,173 @@
+<?php
+/**
+ * LESS CSS Middleware
+ *
+ * Use this middleware with your Slim Framework application
+ * to compile LESS CSS files to plain CSS on-the-fly.
+ *
+ * @author Gerard Sychay <[email protected]>
+ * @version 1.0
+ *
+ * USAGE
+ *
+ * $app = new \Slim\Slim();
+ * $app->add(new \Slim\Extras\Middleware\Less(array(
+ *  'src' => '/path/to/public'
+ * ));
+ *
+ * MIT LICENSE
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+namespace Slim\Extras\Middleware;
+
+use \Slim\Middleware;
+use \Assetic\Filter\LessphpFilter;
+use \Assetic\Filter\CssMinFilter;
+use \Assetic\Filter\CssImportFilter;
+use \Assetic\Asset\FileAsset;
+use \Assetic\Asset\AssetCache;
+use \Assetic\Cache\FilesystemCache;
+
+class Less extends Middleware
+{
+    /**
+     * @var array
+     */
+    public $options;
+
+    /**
+     * Constructor
+     *
+     * @param   array  $options   Configuration options for LESS compilation
+     */
+    public function __construct($options = null)
+    {
+        // Default options
+        $this->options = array(
+            'src' => null,
+            'cache' => true,
+            'cache.dir' => null,
+            'minify' => true,
+            'debug' => false
+        );
+
+        if ($options)
+        {
+            $this->options = array_merge($this->options, (array) $options);
+        }
+
+        if ($this->options['src'] === null)
+        {
+            throw new \InvalidArgumentException("'src' directory is required.");
+        }
+
+        if ($this->options['cache.dir'] === null)
+        {
+            $this->options['cache.dir'] = $this->options['src'];
+        }
+    }
+
+    /**
+     * Debug
+     *
+     * This method will send messages to the Slim Logger at a DEBUG level.
+     */
+    public function debug($arg)
+    {
+        if ($this->options['debug'] === true)
+        {
+            $this->app->getLog()->debug($arg);
+        }
+    }
+
+    /**
+     * Call
+     *
+     * This method will check the HTTP request to see if it is a CSS file. If
+     * so, it will attempt to find a corresponding LESS file. If one is found,
+     * it will compile the file to CSS and serve it, optionally saving the CSS
+     * to a filesystem cache. The request will end at this point.
+     *
+     * If the request is not for a CSS file, or if the corresponding LESS file
+     * is not found, this middleware will pass the request on.
+     */
+    public function call()
+    {
+        $app = $this->app;
+
+        // PHP 5.3 closures do not have access to $this, so we must proxy it in.
+        // However, the proxy only has access to public fields.
+        $self = $this;
+
+        $app->hook('slim.before', function() use ($app, $self) {
+            $path = $app->request()->getPathInfo();
+
+            // Run filter only for requests for CSS files
+            if (preg_match('/\.css$/', $path))
+            {
+                $path = preg_replace('/\.css$/', '.less', $path);
+
+                // Get absolute physical path on filesystem for LESS file
+                $abs = $self->options['src'] . '/' . $path;
+
+                $self->debug("Looking for LESS file: $abs");
+
+                $abs = realpath($abs);
+
+                if ($abs === false)
+                {
+                    // If LESS file is not found, just return
+                    $self->debug("LESS file not found: $abs");
+                    return;
+                }
+
+                $self->debug("LESS file found: $abs");
+
+                // Prepare Assetic
+                $lessFilter = new LessphpFilter();
+                $importFilter = new CssImportFilter();
+                $css = new FileAsset($abs, array($lessFilter, $importFilter));
+
+                if ($self->options['minify'] === true)
+                {
+                    // Minify, if desired
+                    $self->debug("Minifying LESS file: $abs");
+                    $css->ensureFilter(new CssMinFilter());
+                }
+
+                if ($self->options['cache'] === true)
+                {
+                    // Cache results, if desired
+                    $self->debug("Caching LESS file: {$self->options['cache.dir']}");
+                    $cache = new FilesystemCache($self->options['cache.dir']);
+                    $css = new AssetCache($css, $cache);
+                }
+
+                // Render results and exit
+                $res = $app->response();
+                $res['Content-Type'] = 'text/css';
+                $app->halt(200, $css->dump());
+            }
+        });
+
+        $this->next->call();
+    }
+}

Middleware/README.markdown

@@ -73,3 +73,36 @@ Here is some sample code for using PDO provider and securing some routes using r
     );
 
     $app->add(new StrongAuth($config));
+
+## LESS
+
+This middleware will intercept requests for CSS files and attempt to find a
+corresponding [LESS CSS](http://lesscss.org) file. If one is found, it will
+compile the file to CSS and serve it, optionally saving the CSS to a filesystem
+cache. Inspired by [less.js-middleware](https://github.com/emberfeather/less.js-middleware).
+
+### How to use
+
+* `src` - Directory to look for LESS files. Example: if `src` is set to
+  `/path/to/public`, and a request for `http://mysite.com/css/style.css` is
+  received, then it will look for a LESS file in
+  `/path/to/public/css/style.less`. __REQUIRED__.
+* `cache` - Cache CSS file to filesystem. Default is `true`.
+* `cache.dir` - Directory for the cached CSS file. Default is `src`.
+* `minify` - Minify the CSS output. Default is `true`.
+* `debug` - Send debug messages to Slim Logger. Default is `false`.
+
+Example:
+
+    use \Slim\Slim;
+    use \Slim\Extras\Middleware\Less;
+
+    $app = new Slim();
+    $app->add(new Less(array(
+        'src' => '/path/to/public',
+        'cache' => true,
+        'cache.dir' => '/path/to/cache',
+        'minify' => true,
+        'debug' => false
+    ));
+

composer.json

@@ -18,6 +18,9 @@
     ],
     "require": {
         "slim/slim": ">=2.0.0",
+        "kriswallsmith/assetic": "1.0.*",
+        "leafo/lessphp": "0.3.*",
+        "natxet/CssMin": "dev-master#9801e2a0de7ae252ca4f2b85542d75a82047a8b4",
         "php": ">=5.3.0"
     },
     "autoload": {