Flex / ActionScript: Debugging

I ran into an issue while working on a project in flex. I was trying to figure out why something wasn't working and had a large amount of trace calls in my code. It was a complete pain to remove them all. This lead me to develop a debug class that I can turn off at a page level or you can turn if off in the class. It's a first draft. I'd like to make it a Singlton so I can turn it off for the whole project at a page level, but that's for later.

package 
{
public class Debug
{
private var _displayDebug:Boolean = false;
private var _incomingClass:String = "";
private var _logArray:Array = [];

//to stop all debugging set this to false
private var _turnOffDebug:Boolean = false;

/**
* Create the debug object 
* @param display
* @param fileName
* 
*/
public function Debug(display:Boolean, fileName:String): void {
_displayDebug = display;
_incomingClass = fileName;
}


/**
* Display a trace message 
* @param msg
* 
*/
public function log(msg:String) : void {
//override anything a debug passes in
if(_turnOffDebug) {
return;
}

if(!_displayDebug) {
return;
}

var logMessage:String = "["+ new Date() +"]" + _incomingClass + ": " + msg; 

trace(logMessage);
_logArray.push(logMessage);
}
}
}

Using the class is simple. First create an instance of the class and tell if wither you want it on and what the name of the script you're calling it from is named.

var debugObj:Debug = new Debug(true, 'main.mxml');

To turn off debugging for the script just set the first parameter to false. To turn it off for the whole project change the class variable _turnOffDebug to true;

Use the log method to display your statement in the debug area of flash or flex.

debugObj.log('debug statement');

This is a what the trace statement should look like.
[Fri Sep 25 15:03:21 GMT-0700 2009]main.mxml: debug statement

If you have any feedback please send me a message.

Flash / ActionScript: String padding (leading zero)

I was working on a date/time format in Flash and needed a way to pad values out so they always took up the same amount of space. For example making sure a month always has two digits. Making sure it displays a "05" instead of "5". I couldn't find anything built into AS2 or AS3 to do this so I wrote something that would. It allows you to pass in a value and pad either the left or right side up to a given amount of characters.

/**
* This function will pad the left or right side of any variable passed in
* elem [AS object]
* padChar: String
* finalLength: Number
* dir: String
*
* return String
*/
function padValue(elem, padChar, finalLength, dir)
{
  //make sure the direction is in lowercase
  dir = dir.toLowerCase();

  //store the elem length
  var elemLen = elem.toString().length;

  //check the length for escape clause
  if(elemLen >= finalLength)
  {
    return elem;
  }

  //pad the value
  switch(dir)
  {
    default:
    case 'l':
      return padValue(padChar + elem, padChar, finalLength, dir);
      break;
    case 'r':
      return padValue(elem + padChar, padChar, finalLength, dir);
      break;
  }
}

This function accepts an object that can be converted to a string with the toString method, the character you want to use for padding, the final length of the string and wither you want it padded on the left or right side using the character "l" or "r".

For example if you have a number you want padded with three 0 so the final outcome will look like "0005" you would call the function like this.

var exampleNumber:Number = 5;
padValue(exampleNumber, "0", 4, 'l');

If you want to use this in FLEX you might want to type the parameters on the function and give it a return value.

Flex: setTimeout and setInterval replacement

One of the things I learned while moving from AS2 to AS3 is that setTimeout no longer exists. It's been replaced with a Timer class. It can be used like setTimeout or setInterval.

This is how you would use Timer as a setTimeout. The variable tTimer is set to launch 500 ms after start() is run. It will run once and then stop.

import flash.events.TimerEvent;
import flash.utils.Timer;

private function Timer_example()
{
 var tTimer:Timer = new Timer(500, 1);
 tTimer.addEventListener(TimerEvent.TIMER, onTimer);
 tTimer.start();
}
private function onTimer(event:TimerEvent)
{
 trace('callback event has run');
}

Timer can also function like setInterval. The second parameter tells timer how many times it should run. So if you want something to run 100 times then set timer will look like this.

var tTimer:Timer = new Timer(500, 100);

If you want it to run forever then set the interval to 0. If you do this make sure the timer is a global variable so you can run .stop() when it no longer needs to run.