Javascript Callbacks With Object Constructor

Following is a function which creates and object and call the callback (not the exact code but something similar). myObject = function(callback){ var tmpThis = this; this.

Solution 1:

You can use this to access the callback in the context of the newly create object, and call to invoke the callback.

myObject = function(callback){

    var tmpThis = this;
    this.accounts = [];
    tmpThis.accounts[0] = 1;
    tmpThis.accounts[1] = 2;
    callback.call(this);
}

functioncaller(){
    var newMyObject = newmyObject(function() {
        alert(this.accounts[1]);
    }); 
}

Solution 2:

The call hasn't finished yet. Set it to run in the next cycle:

http://fiddle.jshell.net/gWUD9/

myObject = function(callback){

    var tmpThis = this;
    tmpThis.accounts = [];
    tmpThis.accounts[0] = 1;
    tmpThis.accounts[1] = 2;
    setTimeout(callback,1);
}

    var newMyObject = newmyObject(function() {
        alert(newMyObject.accounts[0]);
    }); 

Solution 3:

You could try this:

functionApplication () {

    varself = this;

    myObject = function(callback){

        var tmpThis = this;
        this.accounts = [];
        tmpThis.accounts[0] = 1;
        tmpThis.accounts[1] = 2;
        callback();
    };

    functioncaller(){
        self.newMyObject = new myObject(function() {
            alert(self.newMyObject.accounts[1]);
        }); 
    }
}

Solution 4:

newMyObject is not aware of newMyObject inside of the parameter which is passed into it. It will be undefined.

In other words, when alert(newMyObject.accounts[1]); is run, newMyObject as defined by new myObject wont exist yet.

newMyObject will be undefined when it is executed by the statement callback();, which runs the following code:

function() {
  alert(newMyObject.accounts[1]);
}

Your callback function is being passed into your myObject function. You can just alert(accounts[1]) from within your myObject function.

The pattern you are attempting to use does not usually take a function callback. Usually you would pass in a object of options, which would serve to customize myObject.

It is not clear what you are trying to do.