feat(admin): Fix and improve base path in AssetsBuilder

The `AssetsBuilder` now accepts a base path from its constructor.

Replaced relative base path assumption (`dirname(__DIR__, 7)`) with either:

1. Explicit base path (see constructor parameter), or
2. Implicit base path (the current working directory).

By default, the base path is explicitly set to the `AppConfig`'s base path.

This ensures relative asset paths are loaded according a more reliable base path.

packages/admin/src/Charcoal/Admin/Service/AssetsBuilder.php

@@ -4,6 +4,7 @@
 
 // from kriswallsmith/assetic
 use Assetic\Asset\AssetCollection;
+use Assetic\Asset\AssetInterface;
 use Assetic\Asset\AssetReference;
 use Assetic\Asset\FileAsset;
 use Assetic\Asset\GlobAsset;
@@ -19,39 +20,45 @@
 final class AssetsBuilder
 {
     /**
-     * @var AssetManager $am
+     * @var AssetManager|null
      */
-    private $am;
+    private $assetManager = null;
 
     /**
+     * @var string|null
+     */
+    private $basePath = null;
+
+    /**
+     * @param  string|null $basePath The assets base path.
      * @return void
      */
-    public function __construct(array $data = [])
+    public function __construct($basePath = null)
     {
+        $this->basePath = $basePath;
     }
 
     /**
-     * The __invoke method is called when a script tries to call an object as a function.
+     * Alias of {@see self::build()}.
      *
-     * @param AssetsConfig $config The assets management config.
-     * @return mixed
-     * @link http://php.net/manual/en/language.oop5.magic.php#language.oop5.magic.invoke
+     * @param  AssetsConfig $config The assets management config.
+     * @return AssetManager
      */
     public function __invoke(AssetsConfig $config)
     {
         return $this->build($config);
     }
 
     /**
-     * @param AssetsConfig $config The assets management config.
+     * @param  AssetsConfig $config The assets management config.
      * @return AssetManager
      */
     public function build(AssetsConfig $config)
     {
-        $this->am = new AssetManager();
+        $this->assetManager = new AssetManager();
         $this->parseCollections($config->collections());
 
-        return $this->am;
+        return $this->assetManager;
     }
 
     /**
@@ -73,37 +80,63 @@ private function parseCollections(array $collections)
             $collection = $this->extractFiles($files);
 
             $ac = new AssetCollection($collection);
-            $this->am->set($collectionIdent, $ac);
+            $this->assetManager->set($collectionIdent, $ac);
         }
     }
 
     /**
-     * @param array $files Files to convert to Collection assets.
-     * @return array
+     * @param  string[] $files Files to convert to Collection assets.
+     * @return AssetInterface[]
      */
     private function extractFiles(array $files = [])
     {
-        $basePath = dirname(__DIR__, 7) . '/';
         $collection = [];
 
-        foreach ($files as $f) {
-            // Files with asterisks should be treated as glob.
-            if (strpos($f, '*') !== false) {
-                $collection[] = new GlobAsset($basePath . $f);
+        foreach ($files as $file) {
+            // Files starting with '@' should be treated as assets reference.
+            if ($file[0] === '@') {
+                $file = ltrim($file, '@');
+
+                $collection[] = new AssetReference($this->assetManager, $file);
                 continue;
             }
 
-            // Files starting with '@' should be treated as assets reference.
-            if ($f[0] === '@') {
-                $f = ltrim($f, '@');
+            // If file is not absolute path, prefix with assets base path.
+            if ($this->basePath && !$this->isAbsolutePath($file)) {
+                $file = $this->basePath . '/' . $file;
+            }
 
-                $collection[] = new AssetReference($this->am, $f);
+            // Files with asterisks should be treated as glob.
+            if (strpos($file, '*') !== false) {
+                $collection[] = new GlobAsset($file);
                 continue;
             }
 
-            $collection[] = new FileAsset($basePath . $f);
+            $collection[] = new FileAsset($file);
         }
 
         return $collection;
     }
+
+    /**
+     * Determine if the given file path is an absolute path.
+     *
+     * Note: Adapted from symfony\filesystem.
+     *
+     * @see https://github.com/symfony/symfony/blob/v3.2.2/LICENSE
+     *
+     * @param  string $file A file path.
+     * @return boolean Returns TRUE if the given path is absolute. Otherwise, returns FALSE.
+     */
+    private function isAbsolutePath($file)
+    {
+        $file = (string)$file;
+
+        return strspn($file, '/\\', 0, 1)
+            || (strlen($file) > 3
+                && ctype_alpha($file[0])
+                && substr($file, 1, 1) === ':'
+                && strspn($file, '/\\', 2, 1))
+            || null !== parse_url($file, PHP_URL_SCHEME);
+    }
 }

packages/admin/src/Charcoal/Admin/ServiceProvider/AssetsManagerServiceProvider.php

@@ -2,7 +2,6 @@
 
 namespace Charcoal\Admin\ServiceProvider;
 
-// from pimple
 use Charcoal\Admin\AssetsConfig;
 use Charcoal\Admin\Mustache\AssetsHelpers;
 use Charcoal\Admin\Service\AssetsBuilder;
@@ -83,8 +82,10 @@ protected function registerAssetsManager(Container $container)
             return new AssetsConfig($config);
         };
 
-        $container['assets/builder'] = function () {
-            return new AssetsBuilder();
+        $container['assets/builder'] = function (Container $container) {
+            $appConfig = $container['config'];
+
+            return new AssetsBuilder($appConfig['base_path']);
         };
 
         /**