Help calling nested movie clips from an AS3 class file

Here's what I did:

1) I created a movieclip (book_mc) on the stage. Inside the book is another movieclip (bookPages_mc). Inside of bookPages_mc is a third movieclip (subNav_mc).

2) On the root layer I created another movieclip (button).

3) On "button" I went to Linkage and gave it a base class of my own creation, "MainNav".

Now in the MainNav class I want to tell the subnavigation movieclip to animate.

The problem is - I can't figure out how to reference nested movie clips from an external class.

(For the record - everything has an instance name and has been double checked. The code works from within the FLA but not from an external class.)

Here is my class code (everything works except for the reference to the nested movieclip):

Code:

---

package {
        //imports
        import flash.display.MovieClip;
        import flash.display.DisplayObject;
        import flash.events.MouseEvent;
        import flash.display.SimpleButton;
        import gs.TweenLite;//Importing TweenLite (make sure "gs" folder is in same folder as this file
        import fl.motion.easing.*;

        //declare class
        public class MainNav extends MovieClip {

                public function MainNav() {
                        trace("activate Main Navigation button");
                        this.buttonMode = true;
                        this.addEventListener(MouseEvent.CLICK, handleClick);
                }//end constructor function

                function handleClick(event:MouseEvent):void {
                        //trace("handleClick");
                        book_mc.bookPages_mc.subNav_mc.gotoAndPlay("slide");
                }//end handleClick method

        }//end class
//end package
}

---

Please help! And please consider, when replying, that I pretty much only learned how to use classes YESTERDAY so I'm still a noob at this. Thanks in advance!

Your code is referring to book_mc as if it were a property of the MainNav instance. It is not. book_mc is a property of the main movieclip on which the button lives. The quickest fix is to reach up to the parent to get a reference to book_mc that you can use:

Code:

---

function handleClick(event:MouseEvent):void {
        //trace("handleClick");
        var book_mc:MovieClip = MovieClip(parent).book_mc;
        book_mc.bookPages_mc.subNav_mc.gotoAndPlay("slide");
}//end handleClick method

---

This is not very good object oriented style, since MainNav will now only work when the parent has a book_mc property. They are tightly coupled. For smaller one-off projects, this isn't a big deal. But in order to make something re-useable, you should attempt to abstract out all the code that is specific to the particular structure. You could do this by having a variable in MainNav to keep track of what instance to manipulate, or even what function to call, then set that variable from outside:

Code:

---

package {
        //imports
        import flash.display.MovieClip;
        import flash.display.DisplayObject;
        import flash.events.MouseEvent;
        import flash.display.SimpleButton;
        import gs.TweenLite;//Importing TweenLite (make sure "gs" folder is in same folder as this file
        import fl.motion.easing.*;

        //declare class
        public class MainNav extends MovieClip {

                public var clickFunction:Function;

                public function MainNav() {
                        trace("activate Main Navigation button");
                        this.buttonMode = true;
                        clickFunction = doNothing;
                        this.addEventListener(MouseEvent.CLICK, handleClick);
                }//end constructor function

                private function handleClick(event:MouseEvent):void {
                  clickFunction(event);
                }//end handleClick method

                private function doNothing(event:Event):void{
                }

        }//end class
//end package
}

---

Now by setting button's clickFunction property you can specify the particular function to use outside of MainNav.

In your main swf frame script:

Code:

---

function slideSubNav(event:Event):void{
        book_mc.bookPages_mc.subNav_mc.gotoAndPlay("slide");
}
button.clickFunction = slideSubNav;

---

I almost 100% understand that! Thank you very much. I didn't even know that I could declare a variable typed as a function!

In another forum I got the response to use "MovieClip(this.parent)" to get to the parent of the button (and then more .parents as needed). Your way sounds simpler.

I also appreciate the description of how to make the code re-usable!