Flex: How to use flashvars from different classes

Question

Hi

I am just learning actionscript, so come across the problem

In my application I often call to different web services, and because I don't want to hardcode urls to them in my code, I am passing urls to the services as flashvars.

Currently I am doing it this way:

  public var siteUrl:String;
  public var gameId:String;

      public function main():void
      {
       siteUrl = Application.application.parameters.siteurl;
       gameId = Application.application.parameters.gameid;

Where main is a function, which is called on application's creation complete event.

This way I can call both variables from main file of the application but I want to access them from other files. (other as classes)

So is there a way to create class with constants and init values there with flashvars so I can use them everywhere (after importing of course)

Answer 1

The parameters are just stored in that Application.application.parameters object, and that's static. There's no reason you couldn't access that from other classes in your code.

If you want to write a class that wraps the parameters (maybe validates them or something) you could do that fairly easily. You can use a for each loop to loop over all the parameters. Something like:

var params:Object = Application.application.parameters
for(var name:String in params) {
  var value:String = params[name] as String;
  /* do something with the param */
}

If you want your class to actually verify things then it could just check for each parameter it expects and store it in a local variable.

It really just depends on your own preferences. Some people are fine with accessing the parameters object when they need it. Some people like having the extra code-completion by having a config class that actually defines all the expected config variables.

Update in response to comment:

Instead of having one module declare the variable and have other modules have to depend on that one to access the property it would be cleaner to have a single config module that everything that needs it would all use.

You could use a static class or singleton or some IoC stuff. Just for simplicity I'll show you a way you can do it with a static class.

class MyConfig {
  private static var _infoService:String;
  private static var _someOtherParam:int;

  public static function get infoService():String { return _infoService; }
  public static function get someOtherParam():int { return _someOtherParam; }

  public static function initParams():Void {
    var params:Object = Application.application.parameters;

    _infoService = params.infoservice;

    // just assuming you have a method to convert here.  don't remember the
    // code off the top of my head
    _someOtherParam = convertToInt(params.someOtherParam);
  }
}

Make sure when your app initializes it calls MyConfig.initParams(). You can have that method actually validate that it gets everything it expects and throw exceptions (or return an error) if there's a failure if you want.

Then wherever you need to use that config within your code you just import your config class and access the param. So getting infoService would just be:

var infoService:String = MyConfig.infoService;

Personally I wouldn't use a static class, but it was the easiest to show.