# Calling an action within javascript function w/ ajax

**URL:** <https://www.ruby-forum.com/t/calling-an-action-within-javascript-function-w-ajax/155591>\
**Category:** Rails\
**Created:** [December 14, 2008, 5:02am UTC](https://www.ruby-forum.com/t/calling-an-action-within-javascript-function-w-ajax/155591 "2008-12-14T05:02:04Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![david](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/aeb1de/32.png) [@david](https://www.ruby-forum.com/u/david)\
**Post date:** [December 14, 2008, 5:02am UTC](https://www.ruby-forum.com/t/calling-an-action-within-javascript-function-w-ajax/155591/1 "2008-12-14T05:02:04Z")

</div>

I am trying to call an action within a javscript function using ajax,  
but I am having some problems. I need the ajax call to return a value  
and am thinking I can do this using onComplete and Ajax.Request but I  
am running into some problems. This is the code I am using for the  
Ajax.Request:

```
new Ajax.Request( '/users/username', {
  method: 'post',
  parameters: { username: $('new_user_username').value},
  onComplete: parseResults()
});

```

I have an action called username in my users controller in which I am  
taking the username params passed by the Ajax.Request and seeing if it  
exists in the database. I want to return true/false depending on if  
it exists or not. But I am having trouble even getting the  
Ajax.Request to work.

This is some of the output from the console:

Processing UsersController#username (for 192.168.1.105 at 2008-12-13  
19:52:39) [POST]  
Session ID:  
BAh7BzoMY3NyZl9pZCIlYmNjM2YxODllZWIwMGM1NDkyMzQ0NjUyODMxODAz  
ZTUiCmZsYXNoSUM6J0FjdGlvbkNvbnRyb2xsZXI6OkZsYXNoOjpGbGFzaEhh  
c2h7AAY6CkB1c2VkewA=–d0d5fc597c61c2a295570ee9b118db7ba4285f3f  
Parameters: {“username”=\>“d”, “action”=\>“username”,  
“controller”=\>“users”}

ActionController::InvalidAuthenticityToken  
(ActionController::InvalidAuthenticityToken):

Im not sure how to get around this InvalidAuthenticityToken, anyone  
have any idea whats going on here. Ive been struggling with this for  
a while and am somewhat new to ajax so I could use some help.

---

<div class="post-metadata">

**Author:** ![david](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/aeb1de/32.png) [@david](https://www.ruby-forum.com/u/david)\
**Post date:** [December 14, 2008, 5:04am UTC](https://www.ruby-forum.com/t/calling-an-action-within-javascript-function-w-ajax/155591/2 "2008-12-14T05:04:24Z")

</div>

Im thinking this needs to be a ‘GET’ request in order to return a  
response, but when I change the method to a GET, it calls the show  
action:

Parameters: {“username”=\>“f”, “action”=\>“show”, “id”=\>“username”,  
“controller”=\>“users”}

Stumped…

---

<div class="post-metadata">

**Author:** ![david](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/aeb1de/32.png) [@david](https://www.ruby-forum.com/u/david)\
**Post date:** [December 16, 2008, 4:04am UTC](https://www.ruby-forum.com/t/calling-an-action-within-javascript-function-w-ajax/155591/3 "2008-12-16T04:04:52Z")

</div>

Just use remote\_function and it will generate the appropriate ajax  
call for you - this will make your code much less brittle to Rails  
changes.

[http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html](http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html)

HY