Data binding and ActionScript 3

Data binding is really easy to do in MXML. But what do you do if you need to bind some dynamic objects at runtime using ActionScript? Here’s how I solved this particular problem in the following localization example.

Assume you want to add localization to a MenuBar component and the data provider is an Object. Let’s assume, for the sake of this example, that the Object that will act as dataProvider for the MenuBar component looks like this:

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private var menu:Array = [
    { label: "FILE", children: [
        { label: "NEW" },
        { label: "OPEN" },
        { label: "IMPORT", children: [
            { label: "PROJECT" },
            { label: "OTHER" } ] },
        { type: "separator" },
        { label: "EXIT" } ] },
    { label: "EDIT", children: [
        { label: "UNDO" },
        { label: "REDO" },
        { type: "separator" },
        { label: "CUT" },
        { label: "COPY" },
        { label: "PASTE" } ] },
    { label: "PROJECT", children: [
        { label: "BUILD" },
        { label: "CLEAN" },
        { type: "separator" },
        { label: "EXPORT" } ] },
    { label: "LANGUAGE", children: [
        { label: "ENGLISH", children: [
            { label: "AMERICAN" },
            { label: "BRITISH" } ] },
        { label: "ROMANIAN" } ] }
];

Click to continue…

Progress

For mrm’s TV Guide I needed a visual representation for displaying progress (i.e., saving data to the local database), so I used the built-in ProgressBar component. What’s nice about this component is that you can use three different methods to update the progress bar. You choose one of the methods by setting the mode property in MXML to one of the following values:

• event The control specified by the source property must dispatch progress and completed events. The ProgressBar control uses these events to update its status. The ProgressBar control only updates if the value of the source property extends the EventDispatcher class
• polled The source property must specify an object that exposes bytesLoaded and bytesTotal properties. The ProgressBar control calls these methods to update its status.
• manual You manually update the ProgressBar status. In this mode you specify the maximum and minimum properties and use the setProgress() property method to specify the status. This mode is often used when the indeterminate property is true

Click to continue…