Added support to allow an event handler to be inserted at the beginning of the…

framework/CHANGELOG.md

@@ -186,6 +186,7 @@ Yii Framework 2 Change Log
 - Enh: Added `yii\web\Request::getAuthUser()` and `getAuthPassword()` (qiangxue)
 - Enh: Added summaryOptions and emptyTextOptions to BaseListView (johonunu)
 - Enh: Implemented Oracle column comment reading from another schema (gureedo, samdark)
+- Enh: Added support to allow an event handler to be inserted at the beginning of the existing event handler list (qiangxue)
 - Chg #47: Changed Markdown library to cebe/markdown and adjusted Markdown helper API (cebe)
 - Chg #735: Added back `ActiveField::hiddenInput()` (qiangxue)
 - Chg #1186: Changed `Sort` to use comma to separate multiple sort fields and use negative sign to indicate descending sort (qiangxue)

framework/base/Component.php

@@ -473,12 +473,19 @@ class Component extends Object
      * @param callable $handler the event handler
      * @param mixed $data the data to be passed to the event handler when the event is triggered.
      * When the event handler is invoked, this data can be accessed via [[Event::data]].
+     * @param boolean $append whether to append new event handler to the end of the existing
+     * handler list. If false, the new handler will be inserted at the beginning of the existing
+     * handler list.
      * @see off()
      */
-    public function on($name, $handler, $data = null)
+    public function on($name, $handler, $data = null, $append = true)
     {
         $this->ensureBehaviors();
-        $this->_events[$name][] = [$handler, $data];
+        if ($append || empty($this->_events[$name])) {
+            $this->_events[$name][] = [$handler, $data];
+        } else {
+            array_unshift($this->_events[$name], [$handler, $data]);
+        }
     }
 
     /**
@@ -498,7 +505,6 @@ class Component extends Object
         }
         if ($handler === null) {
             unset($this->_events[$name]);
-
             return true;
         } else {
             $removed = false;

framework/web/ContentTypeNegotiator.php

-<?php
-/**
- * @link http://www.yiiframework.com/
- * @copyright Copyright (c) 2008 Yii Software LLC
- * @license http://www.yiiframework.com/license/
- */
-
-namespace yii\web;
-
-use yii\base\Component;
-
-/**
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @since 2.0
- */
-class ContentTypeNegotiator extends Component
-{
-    /**
-     * @var array list of supported API version numbers. If the current request does not specify a version
-     * number, the first element will be used as the [[version|chosen version number]]. For this reason, you should
-     * put the latest version number at the first. If this property is empty, [[version]] will not be set.
-     */
-    public $supportedVersions = [];
-    /**
-     * @var array list of supported response formats. The array keys are the requested content MIME types,
-     * and the array values are the corresponding response formats. The first element will be used
-     * as the response format if the current request does not specify a content type.
-     */
-    public $supportedFormats = [
-        'application/json' => Response::FORMAT_JSON,
-        'application/xml' => Response::FORMAT_XML,
-    ];
-
-}