5 Replies Latest reply on May 2, 2007 8:48 AM by vezey

    document.getElementById() equivalent?

    vezey
      Is there an equivalent in Actionscript 3.0 to the Javascript method document.getElementById()? It looks like you have to recursively check parents and children through the entire application tree. And I am sooooo lazy, and really don't want to write this method.

      Thanks in advance, Bill
        • 1. Re: document.getElementById() equivalent?
          peterent Level 2
          What are you trying to accomplish? If you have a component (say a VBox) with id="box" and inside of it you have a Button with id="mybutton", then you can get the Button via box.mybutton.
          • 2. Re: document.getElementById() equivalent?
            vezey Level 1
            This flex app is almost entirely Actionscript, and is has several dynamically-generated panel objects, each with it's own set of nested children. Among those children is some checkboxes. Now, when an action is performed in one panel, I want to find a checkbox in one of the other panels and enable/disable.

            Maybe I'm missing something here (usually the case), but my experience is that when the id or name of an object is dynamically generated in an class, rather than in a repeater in the mxml, you can't retrieve that element by simpley calling box.mybutton, but you have to walk the tree up and down, looking for that named or id'd object. I sure hope I'm wrong, but I will play again with the guidance you have sent.

            Did I say thank you for replying? Thank you for replying.

            Yours,
            Bill
            • 3. Re: document.getElementById() equivalent?
              peterent Level 2
              If you have ActionScript code that creates a component you could assign it an id and keep a map of ids-to-components in the code. For example:

              var b:Button = new Button();
              b.id = "helpButton";
              ...

              var map:Object = new Object();
              map["helpButton"] = b;
              map["choiceCombo"] = c;
              etc.

              Now when you want a specific control and know its id, you can get it through the map. If all of your components follow this pattern you should be able to get a component very quickly.
              • 4. Re: document.getElementById() equivalent?
                vezey Level 1
                I very much appreciate your help.

                Your approach of mapping ids makes sense. I had also thought of storing the entire name path from the parentApplication to the lowest component on the tree for each component, and using string manipulation and a series of getChildByName() calls.

                But here's the rub. In ActionScript, it looks like ids assigned dynamically in an class are treated differently than ids created in mxml. When I attempt to call an id in ActionScript that is created dynamically in a class, I get an undefined property error. For example, the class creates a CheckBox:

                var paperAddCheckBox:CheckBox = new CheckBox();
                paperAddCheckBox.id = "add" + paperId;
                paperAddCheckBox.x = 12;
                paperAddCheckBox.y = 27;
                paperAddCheckBox.addEventListener(MouseEvent.CLICK,addRemovePaper);

                And the chekcbox is then added to the the panel or what have you. Later, in a function I want to find this chekcbox and perform some action on it, like set enabled = true or false. To test whether I can actually get to the checkbox, by saying something like:

                Alert.show(add662.enabled.toString());

                I get the following error (using sdk. compiling on the command line):

                Error: Access of undefined property add662

                So, I have a feeling I am being dense, and am missing something obvious that would allow me to access this component by id. I am poised to write a recursive function that will allow me to find any element in an application by id or name, but if this functionality is built into Flex, I would be dancing in the streets. Completely dressed. As a favor to my neighbors, who have had enough of my foolishness.

                Thanks so much,
                Bill
                • 5. Re: document.getElementById() equivalent?
                  vezey Level 1
                  Peter,

                  Oh my hat. I get it. Of course, you call map["helpButton"].myProperty. And that works.

                  You have no idea how much that helps. Should have thought of that myself, blah blah blah.

                  Have a blessed day, Peter.

                  Bill