# Doubt in nil object with ajax

**URL:** <https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874>\
**Category:** Rails\
**Created:** [July 29, 2009, 8:52am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874 "2009-07-29T08:52:13Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 8:52am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/1 "2009-07-29T08:52:13Z")

</div>

hi this is my htnl

\<%= javascript\_include\_tag :defaults %\> \<%= form\_tag nil, { :id =\> 'search\_form' } %\> \<%= text\_field 'recipe', 'name' %\> \<%= end\_form\_tag %\>

\<%= observe\_form :search\_form, :frequency =\> 0.5,  
:update =\> ‘recipe’,  
:url =\> { :action =\> ‘search\_ajax’ } %\>

below is the error i am getting  
Action Controller: Exception caught

Showing _room/search.html.erb_ where line _#9_ raised:

You have a nil object when you didn’t expect it!  
You might have expected an instance of ActiveRecord::Base.  
The error occurred while evaluating nil.[]

## any idea

Karthik.k  
Mobile - +91-9894991640

---

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 10:04am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/2 "2009-07-29T10:04:12Z")

</div>

\<% form\_tag nil, :id =\> ‘search\_form’ do %\>  
\<%= text\_field ‘recipe’, ‘name’ %\>  
\<% end %\>

works fine

---

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 10:37am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/3 "2009-07-29T10:37:34Z")

</div>

hi Rakoth

Thank you

Is there any good tutorial where i can search for text using ajax ruby  
on  
rails  
I am using rails 2.3.2

–  
Karthik.k  
Mobile - +91-9894991640

---

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 10:49am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/4 "2009-07-29T10:49:17Z")

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Hi!

You can find documentation for PrototypeHelper with good examples  
here:  
[http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html](http://api.rubyonrails.org/classes/ActionView/Helpers/PrototypeHelper.html)

---

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 10:44am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/5 "2009-07-29T10:44:01Z")

</div>

hi Rakoth

\<%= form\_tag :acton=\>‘dummy’%\>  
\<%= text\_field\_tag :search\_name%\>  
\<%= form\_tag%\>

  

  
\<%= observe\_field(:search\_name,:frequency =\>  
0.25,:ulr=\>{:action=\>‘search\_ajax’},:with=\>“prefix”,:update=\>:room)%\>

above is my page

i get error  
in observe\_field as

Action Controller: Exception caughtNoMethodError in Room#search

Showing _room/search.html.erb_ where line _#14_ raised:

You have a nil object when you didn’t expect it!  
You might have expected an instance of ActiveRecord::Base.  
The error occurred while evaluating nil.[]

Extracted source (around line _#14_):

11: \<%= form\_tag%\>  
12:

  
13: 
  
14: \<%= observe\_field(:search\_name,:frequency =\>  
0.25,:ulr=\>{:action=\>‘search\_ajax’},:with=\>“prefix”,:update=\>:room)%\>  
15:   
16: 

please help

I am very new to ruby on rails

–  
Karthik.k  
Mobile - +91-9894991640

---

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 11:09am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/6 "2009-07-29T11:09:46Z")

</div>

Also, always check your code, maybe even get your hands on a good  
development environment:

> ```
> <%= observe_field(:search_name,:frequency =>
> 
> ```
> 
> 0.25,:ulr=\>{:action=\>‘search\_ajax’},:with=\>“prefix”,:update=\>:room)%\>

What’s an “ulr”? 🙂

---

<div class="post-metadata">

**Author:** ![karthik](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/9fc348/32.png) [@karthik](https://www.ruby-forum.com/u/karthik)\
**Post date:** [July 29, 2009, 11:13am UTC](https://www.ruby-forum.com/t/doubt-in-nil-object-with-ajax/172874/7 "2009-07-29T11:13:51Z")

</div>

hi jhaagmans

thank you  
i found myself  
I am very new to this ruby on rails, but i need support from you experts

Thank you

–  
Karthik.k  
Mobile - +91-9894991640