Scripting a Preloader Function

You only need one frame at the beginning of your movie to script the preloader function. In this frame you will need a movie clip that contains your loading animation.

The preloader function callback works by using the onEnterFrame event, an event that when you are in the frame it is in, it will play at the frame rate, without any frame advancement. To make it stay ion the same frame we will add a stop first, then the function.

1. Make a layer at the top of your layers, called actions in your movie timeline.

2. Create a keyframe in frame 1 of the actions layer.

3. Click in frame 1 of the actions layer and open the actions panel. Insert a stop on the first line of the actions panel for this frame. Your script appears like this:

stop();

3. On the next line we will set a function callback that will be handled by the event, onEnterFrame. Set  up the function for the _root or main timeline as follows:

stop();
_root.onEnterFrame = function(){
}

Check your syntax.

4. You will next add the action lines within the onEnterframe event on this frame that will decide if you stay in preloader stage or move to the next frame. Within the curly brackets of your function callback, add the condition that will test and compare the values of _totalframes and _framesloaded, global vlaues.

First add your conditional statement: if (_framesloaded >= _totalframes){ }

Check your syntax.  It should look like this:

stop();
_root.onEnterFrame = function(){
   if (_framesloaded >=_totalframes){
   }
}

5. When your movie is fully loaded, or whatever value you give for the right side of the equation,  (_totalframes/2 would mean only half frames loaded), then you can advance to the next frame. Add the script nextFrame();;

stop();
_root.onEnterFrame = function(){
    if (_framesloaded >=_totalframes){
        nextFrame();
    }
}

Check your syntax.

Test your preloader!

We can add a dynamic loading bar now! this is the next tutorial!