Loading Data By Variable Name (AS3)

Question

I've got a code that reads a sound in the language chosen by the user. For now, my code is :

if (english == true){
 helloSound = new hello_english(); 
}
if (french == true){
 helloSound = new hello_french(); 
}

As I've got even more words and even more languages to add, I want to simplify my code.

What I'd like to do :

When app launch, the user choose the language.

english.addEventListener(MouseEvent.CLICK, goEnglish, false, 0, true);
french.addEventListener(MouseEvent.CLICK, goFrench, false, 0, true);

function goEnglish(event:MouseEvent):void {
var audioChosen = "english";
}
function goFrench(event:MouseEvent):void {
var audioChosen = "french";
}

And then is it possible to do something like?

 helloSound = new hello_(audioChosen)();

So, in this example, the sound that will be play, would be : hello_english

score 3 · Accepted Answer · edited Sep 05 '19 at 01:43

Using getDefinitionByName

To instantiate an object using its class name from a string, you can use getDefinitionByName, as mentioned in this question: Instantiate a class from a string in ActionScript 3

// Find the relevant class:
var helloSoundFileClass:Class = getDefinitionByName("hello_english") as Class;
// Create a new instance of the class we found:
var helloSound:Sound = new helloSoundFileClass();

Example usage

Here's an example based on the original code:

var audioChosen:String;
var helloSound:Sound;
var goodbyeSound:Sound;

english.addEventListener(MouseEvent.CLICK, goEnglish, false, 0, true);
french.addEventListener(MouseEvent.CLICK, goFrench, false, 0, true);

// Set a "default" language.
audioChosen = "english"
onLanguageChanged();

// When user chooses a language:
function goEnglish(e:MouseEvent):void {
    audioChosen = "english";
    onLanguageChanged();
}
function goFrench(event:MouseEvent):void {
    audioChosen = "french";
    onLanguageChanged();
}

function onLanguageChanged() {
    // Find the relevant classes:
    var helloSoundFileClass:Class = getDefinitionByName("hello_" + audioChosen) as Class;
    var goodbyeSoundFileClass:Class = getDefinitionByName("goodbye_" + audioChosen) as Class;

    // Create a new instance of the class we found:
    helloSound = new helloSoundFileClass();
    goodbyeSound = new goodbyeSoundFileClass();
}

...

// Later, we can play the sounds:
helloSound.play();
goodbyeSound.play();

VC.One · Answer 2 · 2019-09-05T04:00:59.237

Just an alternative way to achieve desired result.

Has one central function setLanguage to check/set according to relevant button.
Loads MP3 files instead of using Sound from Library.

You could try:

//english.addEventListener(MouseEvent.CLICK, goEnglish, false, 0, true);
//french.addEventListener(MouseEvent.CLICK, goFrench, false, 0, true);

var helloSound :Sound;
var audioChannel :SoundChannel = new SoundChannel();
var isAudioPlaying :Boolean = false;
var audioChosen :String = "";

english.addEventListener(MouseEvent.CLICK, setLanguage);
french.addEventListener(MouseEvent.CLICK, setLanguage);
spanish.addEventListener(MouseEvent.CLICK, setLanguage);
japanese.addEventListener(MouseEvent.CLICK, setLanguage);
greek.addEventListener(MouseEvent.CLICK, setLanguage);

function setLanguage( evt :MouseEvent ) :void 
{
    //trace("clicked is : " + evt.target.name ); //# get instance name of clicked: eg... "english"
    var user_language = evt.target.name; //# will set to instance name of "evt" that triggered a "clicked" event

    //# check instance name of clicked object
    switch ( user_language )
    {
        case "english": trace("Hello World!"); audioChosen = "english"; break;
        case "french": trace("Bonjour Monde!"); audioChosen = "french"; break;
        case "spanish": trace("Hola Mundo!"); audioChosen = "spanish"; break;
        case "japanese": trace("こんにちは世界!"); audioChosen = "japanese"; break;
        case "greek": trace("γειά σου κόσμος!"); audioChosen = "greek"; break;

    }

    //# also can check with IF / ELSE version instead of the above SWITCH checking...
    //if( user_language == "english" ) { trace("Hello World!"); audioChosen = "english"; }
    //if( user_language == "japanese" ) { trace("こんにちは世界!"); audioChosen = "japanese"; }

    //# run some other function...
    do_Some_Action();
}

function do_Some_Action() :void 
{
    trace("User has chosen language: " + audioChosen);
    trace("::::::::::::::::::::::::::::::::::::::::");

    //# check if the URL is correct, example of expected: "hello_english.mp3"
    //var temp :String = "hello_" + audioChosen + ".mp3"; trace("temp is: " + temp);

    if ( audioChannel == null ) { audioChannel = new SoundChannel(); }
    if ( isAudioPlaying == true ) { audioChannel.stop(); }

    helloSound = new Sound();
    helloSound.load( new URLRequest( "hello_" + audioChosen + ".mp3" ) );
    audioChannel = helloSound.play();
    isAudioPlaying = true;
}

Loading Data By Variable Name (AS3)

2 Answers2

Using getDefinitionByName

Example usage