strategy

main.js

var Button = function(id) {
	this.id = id;
	this.$context = $(id);
	this.$context.on('click', $.proxy(this.handleClick, this));
}
Button.prototype.changeAction = function(action) {
	this.action = action;
}
Button.prototype.handleClick = function() {
	this.action();
}


var btn = new Button('#button-expand');
btn.changeAction(function() {
	console.log('logging in!');
	
	btn.changeAction(function() {
		console.log('hitting facebook');
	});
});