Examples of call, apply, and bind

call_apply_bind.js

// Our implementation of Function.prototype.bind

Function.prototype.bind = function() {
  var __method = this, args = Array.prototype.slice.call(arguments), object = args.shift();
  return function() {
    var local_args = args.concat(Array.prototype.slice.call(arguments));
    if (this !== window) local_args.push(this);
    return __method.apply(object, local_args);
  }
};



// Examples of call, apply, and bind

function Module() {
  this.items = ["one", "two", "three"];
}

Module.prototype.print = function () {
  console.log(this.items.join(" ") + " / " + Array.prototype.join.call(arguments, " "));
};

var m = new Module();
m.print("called", "on", "an", "instance", "of", "Module");

var foo = { items: ["four", "five", "six"]}
Module.prototype.print.call(foo, "called", "via", "Function.prototype.call");
Module.prototype.print.apply(foo, ["called", "via", "Function.prototype.apply"]);
var boundFunction = Module.prototype.print.bind(foo, "called", "via", "Function.prototype.bind");
boundFunction();

module_pattern.js

var Singleton = function () {
  var privateInfo = "you can't see this";
  return {
    exposePrivateInfo: function () {
      console.log(privateInfo);
    }
  };
}();

real_world_usage.js

var Foo = function () {
  
  $(this.setup.bind(this));
  
  $(functionName);
  $(function () {
    functionName();
  });
}


Foo.prototype.bar = function () {
  console.log("hello");
};


var f = new Foo();
var f2 = new Foo();


f.bar();
f2.bar();
f.bar = function () {
  console.log("I was changed!");
}
f.bar();





var Module = function () {
  this.name = "Ray";
  $(this.setup.bind(this));
};

Module.prototype.setup = function () {
  $('div').click(this.listenClick.bind(this));
};

Module.prototype.listenClick = function (evt) {
  var domobject = $(evt.currentTarget);
  alert(this.name);
};