[FLEX-28929] Binding not working in Flex 4 but working in Flex 3

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Adobe Flex SDK 4.5.1 (Release)
• Component/s: Data Binding
• Environment: Affected OS(s): All OS Platforms; Language Found: English
• Assignee: Unassigned
• Reporter: Adobe JIRA
• Created: 02/Nov/11 05:22
• Updated: 07/Nov/11 06:10

Description

When upgrading our application from Flex 3 to Flex 4, we noticed some issues where bindings are no longer correctly executed. Attached is an isolated example and the sources (and the generated AS code) for a Flex 3 and a Flex 4 sample. The Flex 3 code works, while the Flex 4 code does not.

While comparing the generated code, I noticed that the bindings that are created are slightly different. In the Flex 3 example, a anonymous function is passed to handle the update of the binding, while in the Flex 4 example, a null value is passed. There are some other differences, but this was the one that caught my attention.

A workaround is to add the binding via BindingUtils.bindProperty() in the creationComplete handler of the component where the binding is defined.

***

Binding code:

<mx:CheckBox id="c"
label="Test"
selected="

{DataGridContainer(parent.parent.parent).checked}

"/>

Flex 3 generated:

new mx.binding.Binding(this,
function():Boolean

{ return (DataGridContainer(parent.parent.parent).checked); },
function(_sourceFunctionReturnValue:Boolean):void
{ c.selected = _sourceFunctionReturnValue; },
"c.selected");

Flex 4 generated:

new mx.binding.Binding(this,
function():Boolean
{ return (DataGridContainer(parent.parent.parent).checked); }

,
null,
"c.selected");

Workaround:

BindingUtils.bindProperty(c, "selected", DataGridContainer(parent.parent.parent), "checked");