Javascript object reference pattern

Question

I have one object:

var callback = {
    onValueChange: function () { },
    onTabPressed: function () { },
    onFocus: function () { }
};

On my page, i have different editors, like textEditor and numericEditor, and i bind them separately:

function bindEditors() {
    var editors = $(".editor");
    editors.each(function (i) {
        var editor = $(this);
        var editorType = editor.attr("data-editorType");

        if (editorType == "textEditor") {
            bindTextEditor(editor);

        } else if (editorType == "numericEditor") {
            bindNumericEditor();
        }
    });
};
function bindTextEditor(editor) {
    editor.bind("change", function () {
        // calculate value
        callback.onValueChange($(this), value);
    });
};
function bindNumericEditor(editor) {
    editor.bind("change", function () {
        // calculate value
        callback.onValueChange($(this), value);
    });
};

My question is:

Is ok to keep callback object outside of the binding functions? Wouldn't each binding function create a copy of the callback object? (which uses extra memory)

Or should i pass the callback object as a parameter to each of the binding functions?

score 1 · Accepted Answer · 2013-05-30 07:58:34Z

1

It doesn't create copies of the enclosed object, just references to the same object, so I wouldn't worry about that. And I definitely wouldn't pass callback as a parameter.

I don't think there's anything crazily wrong with what you wrote, but if you wanted to cut down on your code's complexity, you could just bind it once and do the switch inside the binding itself:

$(".editor").bind("change", function(){
  var editor = $(this);
  var editorType = editor.attr("data-editorType");

  if (editorType == "textEditor") {
    //calculate value
  } else if (editorType == "numericEditor") {
    //calculate value
  }

  callback.onValueChange(editor, value);
});

That probably doesn't perform any differently, but it's cleaner.

edited May 30, 2013 at 7:58

answered May 30, 2013 at 7:19

user24359

Sign up to request clarification or add additional context in comments.

Comments

Thomas Junk · Accepted Answer · 2013-05-30 07:15:12Z

1

1) Is ok to keep callback object outside of the binding functions?

Absolutely!

2) Wouldn't each binding function create a copy of the callback object?

No.

3) Or should i pass the callback object as a parameter to each of the binding functions? No.

answered May 30, 2013 at 7:15

Thomas Junk

5,6962 gold badges34 silver badges48 bronze badges

Collectives™ on Stack Overflow

Javascript object reference pattern

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related