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Is there much significance in the choice of $.ajax() over $.post()?

Answer 1

+1 A:

$.ajax gives you a bit flexibility, you can choose POST or GET and you can leave $.post in current case

infinity 2010-10-24 16:00:52

This doesn't address the issue of the post, which isn't really about post vs. ajax, it's about the built-in jQuery function (globalEval) that gets run as a side effect of the way he used ajax (and because of that function, there is a significant difference between post and ajax in this case).

machineghost 2010-10-24 16:20:06

Answer 2

A:

$.ajax give better control and flexibility over the params while $.post, $.get are just shorthands

Lorenzo 2010-10-24 16:03:38

Answer 3

+3 A:

Generally speaking, $.post() is indeed just a shorthand to $.ajax.

The specialty in the question you link to and Nick's answer is the fact that the OP wants to execute Javascript code directly. There is a dataType parameter just for that:

dataType: 'script'

this parameter cannot be specified in $.post, only in $.ajax. Setting this parameter causes the returned data to be evaluated by jQuery's globalEval() function, which executes the JS code in the global context and not in the context of the success callback.

See docs on dataType here.

Pekka 2010-10-24 16:06:46

Answer 4

+1 A:

The difference in your examples has nothing to do really between .post() and .ajax(), it's just about built-in JS eval() vs. jQuery.globalEval(). These differences are covered here:

http://api.jquery.com/jQuery.globalEval/

but they don't do a great job of explaining why it matters. Here's the issue: if you do just do an ordinary eval of a line like:

 var foo = 5;

from inside a .post() call, that "foo" variable will only live inside that call. If you later do anything else on that page, that variable will be gone, because it was scoped to the anonymous that you passed in to your "post". In contrast, the jQuery "globalEval" method will make that foo variable a property of window, ie. it will be in the global scope. This means that any other function you subsequently run will still have access to it.

(Side Note: Putting lots of variables in the global scope isn't actually always a good idea, because of potential naming conflicts, so the globalEval isn't always better.)

In any case, you don't have to stop using post to get the benefits of your returned script's variables being global. Just do:

$.globalEval(data);

in your post function instead of "eval" and you'll be all set.

machineghost 2010-10-24 16:10:56

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Is there much significance in the choice of $.ajax() over $.post()?

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