Added comments and slight tweak of code style purely to aid my own lo…

…ng-term understanding of this. Core mechanism not affected.
philipooo · Feb 26, 2012 · 26c9303 · 26c9303
1 parent 3e63a39
commit 26c9303
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Showing 2 changed files with 22 additions and 17 deletions.
diff --git a/src/binding/defaultBindings.js b/src/binding/defaultBindings.js
@@ -133,24 +133,20 @@ ko.bindingHandlers['value'] = {
             var elementValue = ko.selectExtensions.readValue(element);
             ko.jsonExpressionRewriting.writeValueToProperty(modelValue, allBindingsAccessor, 'value', elementValue);
         }
-        function asyncValueUpdateHandler() {
-            setTimeout(valueUpdateHandler);
-        }
-        function ieAutoCompleteHackNeeded() {
-            return ko.utils.ieVersion && element.tagName.toLowerCase() == "input" && element.type == "text"
-                && element.autocomplete != "off" && (!element.form || element.form.autocomplete != "off");            
-        }
 
-        if (ieAutoCompleteHackNeeded() && ko.utils.arrayIndexOf(eventsToCatch, "propertychange") == -1) {
-            var propertyChanged = false, originalValueUpdateHandler = valueUpdateHandler;
-            valueUpdateHandler = function() {
-                if (propertyChanged) {
-                    originalValueUpdateHandler();
-                    propertyChanged = false;
+        // Workaround for https://github.com/SteveSanderson/knockout/issues/122
+        // IE doesn't fire "change" events on textboxes if the user selects a value from its autocomplete list
+        var ieAutoCompleteHackNeeded = ko.utils.ieVersion && element.tagName.toLowerCase() == "input" && element.type == "text"
+                                       && element.autocomplete != "off" && (!element.form || element.form.autocomplete != "off");
+        if (ieAutoCompleteHackNeeded && ko.utils.arrayIndexOf(eventsToCatch, "propertychange") == -1) {
+            var propertyChangedFired = false;
+            ko.utils.registerEventHandler(element, "propertychange", function () { propertyChangedFired = true });
+            ko.utils.registerEventHandler(element, "blur", function() {
+                if (propertyChangedFired) {
+                    propertyChangedFired = false;
+                    valueUpdateHandler();
                 }
-            };
-            ko.utils.registerEventHandler(element, "propertychange", function () { propertyChanged = true; });
-            ko.utils.registerEventHandler(element, "blur", valueUpdateHandler);
+            });
         }
 
         ko.utils.arrayForEach(eventsToCatch, function(eventName) {
@@ -159,7 +155,7 @@ ko.bindingHandlers['value'] = {
             // (otherwise, ko.selectExtensions.readValue(this) will receive the control's value *before* the key event)
             var handler = valueUpdateHandler;
             if (ko.utils.stringStartsWith(eventName, "after")) {
-                handler = asyncValueUpdateHandler;
+                handler = function() { setTimeout(valueUpdateHandler, 0) };
                 eventName = eventName.substring("after".length);
             }
             ko.utils.registerEventHandler(element, eventName, handler);

diff --git a/src/binding/jsonExpressionRewriting.js b/src/binding/jsonExpressionRewriting.js
@@ -164,6 +164,15 @@ ko.jsonExpressionRewriting = (function () {
             return false;
         },
 
+        // Internal, private KO utility for updating model properties from within bindings
+        // property:            If the property being updated is (or might be) an observable, pass it here
+        //                      If it turns out to be a writable observable, it will be written to directly
+        // allBindingsAccessor: All bindings in the current execution context.
+        //                      This will be searched for a '_ko_property_writers' property in case you're writing to a non-observable
+        // key:                 The key identifying the property to be written. Example: for { hasFocus: myValue }, write to 'myValue' by specifying the key 'hasFocus'
+        // value:               The value to be written
+        // checkIfDifferent:    If true, and if the property being written is a writable observable, the value will only be written if
+        //                      it is !== existing value on that writable observable
         writeValueToProperty: function(property, allBindingsAccessor, key, value, checkIfDifferent) {
             if (!property || !ko.isWriteableObservable(property)) {
                 var propWriters = allBindingsAccessor()['_ko_property_writers'];