Extract static content handling into reusable class

[thekid]

This pull request extracts the handling of files, including mime type detection, HEAD, conditional and range request handling from the web.handlers.FilesFrom class into a reusable class web.io.StaticContent. Its standalone usage is:

$content= (new StaticContent())->with(['Cache-Control' => '...']);
return $content->serve($req, $res, new File('...'), 'image/gif');

Instead of having to inherit from FilesFrom, implementations can now use StaticContent, e.g.:

diff --git a/src/main/php/web/frontend/AssetsFrom.class.php b/src/main/php/web/frontend/AssetsFrom.class.php
index 442631f..08e0528 100755
--- a/src/main/php/web/frontend/AssetsFrom.class.php
+++ b/src/main/php/web/frontend/AssetsFrom.class.php
@@ -2,7 +2,8 @@
 
 use io\Path;
 use util\MimeType;
-use web\handler\FilesFrom;
+use web\Handler;
+use web\io\StaticContent;
 
 /**
  * Serves assets from a given path. Checks for files with extensions matching
@@ -14,7 +15,7 @@ use web\handler\FilesFrom;
  * @see  https://www.rootusers.com/gzip-vs-bzip2-vs-xz-performance-comparison/
  * @see  https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding
  */
-class AssetsFrom extends FilesFrom {
+class AssetsFrom implements Handler {
   const PREFERENCE= ['br', 'bzip2', 'gzip', 'deflate'];
   const ENCODINGS= [
     'br'       => '.br',
@@ -26,7 +27,7 @@ class AssetsFrom extends FilesFrom {
   ];
 
   private $sources= [];
-  private $preference;
+  private $preference, $content;
 
   /** @param io.Path|io.Folder|string|io.Path[]|io.Folder[]|string[] $sources */
   public function __construct($sources) {
@@ -34,7 +35,18 @@ class AssetsFrom extends FilesFrom {
     foreach (is_array($sources) ? $sources : [$sources] as $source) {
       $this->sources[]= $source instanceof Path ? $source : new Path($source);
     }
-    parent::__construct($this->sources[0] ?? '.');
+    $this->content= new StaticContent();
+  }
+
+  /**
+   * Adds headers to successful responses, either from an array or a function.
+   *
+   * @param  [:string]|function(util.URI, io.File, string): iterable $headers
+   * @return self
+   */
+  public function with($headers) {
+    $this->content->with($headers);
+    return $this;
   }
 
   /**
@@ -122,12 +134,12 @@ class AssetsFrom extends FilesFrom {
           $response->header('Vary', 'Accept-Encoding');
           '*' === $encoding || $response->header('Content-Encoding', $encoding);
 
-          return $this->serve($request, $response, $target->asFile(), $this->mime($path));
+          return $this->content->serve($request, $response, $target->asFile(), $this->mime($path));
         }
       }
     }
 
     // Target does not exist in any of the sources, generate a 404
-    return $this->serve($request, $response, null);
+    return $this->content->serve($request, $response, null);
   }
 }
\ No newline at end of file

See also xp-forge/frontend#39

[thekid]

Released in https://github.com/xp-forge/web/releases/tag/v4.0.0