flash - How to pass arguments into event listener function in flex/actionscript?

Question

Since when using sql lite if you try and do a function at the same moment it throws an error, im just trying to make a function that will check if its executing, and if it is try again in 10 milliseconds, this exact function works fine if i dont have to pass any arguments to the function but im confused how I can pass the vars back into the function it'll be executing.

I want to do:

timer.addEventListener(TimerEvent.TIMER, saveChat(username, chatBoxText));

But it will only allow me to do:

timer.addEventListener(TimerEvent.TIMER, saveChat);

It gives me this compile error:

1067: Implicit coercion of a value of type void to an unrelated type Function

How can I get this to pass this limitation?

Here's what I've got:

public function saveChat(username:String, chatBoxText:String, e:TimerEvent=null):void
{
    var timer:Timer = new Timer(10, 1);
    timer.addEventListener(TimerEvent.TIMER, saveChat);

    if(!saveChatSql.executing)
    {
        saveChatSql.text = "UPDATE active_chats SET convo = '"+chatBoxText+"' WHERE username = '"+username+"';";
        saveChatSql.execute();
    }
    else timer.start();
}

Answer 1

A function called by a listener can only have one argument, which is the event triggering it.

listener:Function — The listener function that processes the event. This function must accept an Event object as its only parameter and must return nothing, as this example shows:

function(evt:Event):void

Source

You can get around this by having the function called by the event call another function with the required arguments:

timer.addEventListener(TimerEvent.TIMER, _saveChat);
function _saveChat(e:TimerEvent):void
{
    saveChat(arg, arg, arg);
}

function saveChat(arg1:type, arg2:type, arg3:type):void
{
    // Your logic.
}

Another thing you can do create a custom event class that extends flash.events.Event and create properties that you need within.

package
{
    import flash.events.Event;

    public class CustomEvent extends Event
    {
        // Your custom event 'types'.
        public static const SAVE_CHAT:String = "saveChat";

        // Your custom properties.
        public var username:String;
        public var chatBoxText:String;

        // Constructor.
        public function CustomEvent(type:String, bubbles:Boolean=false, cancelable:Boolean=false):void
        {
            super(type, bubbles, cancelable);
        }
    }
}

Then you can dispatch this with properties defined:

timer.addEventListener(TimerEvent.TIMER, _saveChat);
function _saveChat(e:TimerEvent):void
{
    var evt:CustomEvent = new CustomEvent(CustomEvent.SAVE_CHAT);

    evt.username = "Marty";
    evt.chatBoxText = "Custom events are easy.";

    dispatchEvent(evt);
}

And listen for it:

addEventListener(CustomEvent.SAVE_CHAT, saveChat);
function saveChat(e:CustomEvent):void
{
    trace(e.username + ": " + e.chatBoxText);
    // Output: Marty: Custom events are easy.
}