encode/decode images directives

js/mage/adminhtml/events.js

@@ -10,7 +10,6 @@
  * @copyright   Copyright (c) 2006-2020 Magento, Inc. (https://www.magento.com)
  * @license     https://opensource.org/licenses/afl-3.0.php  Academic Free License (AFL 3.0)
  */
-// from http://www.someelement.com/2007/03/eventpublisher-custom-events-la-pubsub.html
 varienEvents = Class.create();
 
 varienEvents.prototype = {
@@ -120,7 +119,50 @@ varienEvents.prototype = {
             }
         }
         return results;
-    }
+    },
+
+    /**
+     * Collect and modify value of arg synchronously in succession and return its new value.
+     * In order to use, call attachEventHandler and add function handlers with eventName.
+     * Then call fireEventReducer with eventName and any argument to have its value accumulatively modified.
+     * Event handlers will be applied to argument in order of first attached to last attached.
+     * @param {String} eventName
+     * @param {*} arg
+     */
+    fireEventReducer: function (eventName, arg) {
+        var evtName = eventName + this.eventPrefix,
+            result = arg,
+            len,
+            i;
+
+        if (!this.arrEvents[evtName]) {
+            return result;
+        }
+
+        len = this.arrEvents[evtName].length; //optimization
+
+        for (i = 0; i < len; i++) {
+            /* eslint-disable max-depth */
+            try {
+                result = this.arrEvents[evtName][i].method(result);
+            } catch (e) {
+                if (this.id) {
+                    alert({
+                        content: 'error: error in ' + this.id + '.fireEventReducer():\n\nevent name: ' +
+                        eventName + '\n\nerror message: ' + e.message
+                    });
+                } else {
+                    alert({
+                        content: 'error: error in [unknown object].fireEventReducer():\n\nevent name: ' +
+                        eventName + '\n\nerror message: ' + e.message
+                    });
+                }
+            }
+            /* eslint-disable max-depth */
+        }
+
+        return result;
+    },
 };
 
 varienGlobalEvents = new varienEvents();