Singleton Class in Flex

Question

I have a doubt,.... How would you create a Singleton class in Flex...

Is there any convention like the class name should eb Singleton or it should extend any other class.

How many Singleton class can a project have?

Can anyone say the real time usage of a Singleton class?

I am planning to keep my components label texts in a Singleton class... Is it a good approach.

Answer 1

Can of worms asking about singletons!

There are a few different options about creating singletons mainly due to AS3 not having private constructors. Here's the pattern we use.

package com.foo.bar {

    public class Blah {

        private static var instance : Blah;

        public function Blah( enforcer : SingletonEnforcer ) {}

        public static function getInstance() : Blah {
            if (!instance) {
                instance = new Blah( new SingletonEnforcer() );
            }
            return instance;
        }

        ...
    }
}
class SingletonEnforcer{}

Note that the SingletonEnforcer class is internal so can only be used by the Blah class (effectively). No-one can directly instantiate the class, they have to go through the getInstance() function.