Prototype: bind() vs bindAsEventListener()

[danf]

Can anyone tell me what the difference is between these two protoype
methods?
They are extensions of Javascript's Function class.

Is bindAsEventListener just used to be compatible with IE's Event
model?
I'm thinking the only difference between the 2 methods is that
bindAsEventListener passes the event into the function.

I want to know how I can practically apply these.

METHODS FROM prototype-1.5.0_rc1.js
Function.prototype.bind = function() {
var __method = this, args = $A(arguments), object = args.shift();
return function() {
return __method.apply(object, args.concat($A(arguments)));
}
}

Function.prototype.bindAsEventListener = function(object) {
var __method = this, args = $A(arguments), object = args.shift();
return function(event) {
return __method.apply(object, [( event ||
window.event)].concat(args).concat($A(arguments)));
}
}

 

[VK]

Can anyone tell me what the difference is between these two protoype
methods?

I don't know, but this may help:

<http://wiki.script.aculo.us/scriptaculous/show/Function.prototype.bind>
<http://wiki.script.aculo.us/scriptaculous/show/Function.prototype.bindAsEventListener>

 

[Peter Michaux]

Can anyone tell me what the difference is between these two protoype
methods?

If you are absolutely stuck using Prototype and can't escape it then
the best place for Prototype-specific questions is the Rails spinoffs
list. It is the de facto Prototype support list.

<URL: http://groups.google.com/group/rubyonrails-spinoffs>

Peter

 

[Yanick]

Can anyone tell me what the difference is between these two protoype
methods?
They are extensions of Javascript's Function class.

Roughly, the only different is that bindAsEventListener sets the first
argument of the function (arguments[0]) as the event objet. But also,
it ensures that event is consistent in both IE and firefox. Meaning
that you won't need to add this line : event = event || window.event,
at the beginning of you event function. So, yes, it is cross-browser
compatible.

Consider this :

function clickEvent(arg1, arg2) {
alert( "this = " + this + "\narg1 = " + arg1 + "\narg2 = " + arg2 );
}

var element1 = $('someElement1');
// this = inconsistent, arg1 = inconsistent, arg2 = undefined
element1.onclick = clickEvent;

var element2 = $('someElement2');
// this = element2, arg1 = 1, arg2 = 2
element2.onclick = clickEvent.bind(element2, 1, 2);

var element3 = $('someElement3');
// this = element3, arg1 = event, arg2 = 1
element3.onclick = clickEvent.bindAsEventListener(element3, 1, 2);

Is bindAsEventListener just used to be compatible with IE's Event
model?

As you see, bind and bindAsEventListener may be applied to any DOM
event model as they ensure a consistency in most implementations.

I'm thinking the only difference between the 2 methods is that
bindAsEventListener passes the event into the function.

Yes, that's the main thing, but as I said, bindAsEventListener's first
parameter will always be the event object in most browsers (meaning
that the only browsers making exception here are barely used by less
than 8% of the population, and in most case, they don't even implement
proper JS, CSS, XML, etc. see
http://www.w3schools.com/browsers/browsers_stats.asp)


I suggest that you read about function binding to have a better
understanding of what these two functions actually do in your code. A
good start is here :
http://developer.mozilla.org/en/doc...nce:Operators:Special_Operators:this_Operator

 

[tdan]

Thanks for the response - and the link was a great resource.

Can anyone tell me what the difference is between these two protoype
methods?
They are extensions of Javascript's Function class.

Roughly, the only different is that bindAsEventListener sets the first
argument of the function (arguments[0]) as the event objet. But also,
it ensures that event is consistent in both IE and firefox. Meaning
that you won't need to add this line : event = event || window.event,
at the beginning of you event function. So, yes, it is cross-browser
compatible.

Consider this :

function clickEvent(arg1, arg2) {
alert( "this = " + this + "\narg1 = " + arg1 + "\narg2 = " + arg2 );
}

var element1 = $('someElement1');
// this = inconsistent, arg1 = inconsistent, arg2 = undefined
element1.onclick = clickEvent;

var element2 = $('someElement2');
// this = element2, arg1 = 1, arg2 = 2
element2.onclick = clickEvent.bind(element2, 1, 2);

var element3 = $('someElement3');
// this = element3, arg1 = event, arg2 = 1
element3.onclick = clickEvent.bindAsEventListener(element3, 1, 2);

Is bindAsEventListener just used to be compatible with IE's Event
model?

As you see, bind and bindAsEventListener may be applied to any DOM
event model as they ensure a consistency in most implementations.

I'm thinking the only difference between the 2 methods is that
bindAsEventListener passes the event into the function.

Yes, that's the main thing, but as I said, bindAsEventListener's first
parameter will always be the event object in most browsers (meaning
that the only browsers making exception here are barely used by less
than 8% of the population, and in most case, they don't even implement
proper JS, CSS, XML, etc. see
http://www.w3schools.com/browsers/browsers_stats.asp)


I suggest that you read about function binding to have a better
understanding of what these two functions actually do in your code. A
good start is here :
http://developer.mozilla.org/en/doc...nce:Operators:Special_Operators:this_Operator