# RJS Change Background Color

**URL:** <https://www.ruby-forum.com/t/rjs-change-background-color/101806>\
**Category:** Rails\
**Created:** [August 8, 2006, 2:07am UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806 "2006-08-08T02:07:34Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![davidjrice](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@davidjrice](https://www.ruby-forum.com/u/davidjrice)\
**Post date:** [August 8, 2006, 2:07am UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806/1 "2006-08-08T02:07:34Z")

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What’s the page.method to change the background color of a DOM element?  
I’m  
trying to change the background color of a couple of styled

- 's when  
an  
Ajax link is clicked.

Thanks,  
David

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**Author:** ![davidjrice](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@davidjrice](https://www.ruby-forum.com/u/davidjrice)\
**Post date:** [August 8, 2006, 2:34am UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806/2 "2006-08-08T02:34:36Z")

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David,

Use Element.addClassName(element, className) and CSS.

Hope this helps,  
Zack

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<div class="post-metadata">

**Author:** ![davidjrice](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@davidjrice](https://www.ruby-forum.com/u/davidjrice)\
**Post date:** [August 8, 2006, 9:21pm UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806/3 "2006-08-08T21:21:30Z")

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Thanks for the answer, Zack.

I’m not sure quite how to use that method, though. Fitting  
Element.addClassName into an RJS file won’t work, and  
page.add\_class\_name"id of element", “class name” throws an error  
saying AddClassName is not  
defined.

- David

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<div class="post-metadata">

**Author:** ![davidjrice](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@davidjrice](https://www.ruby-forum.com/u/davidjrice)\
**Post date:** [August 9, 2006, 6:49am UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806/4 "2006-08-09T06:49:14Z")

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page\<\<"$(‘theElement’).style.background=‘red’" also works for me.

The $ javascript operator fetches the element with the name of its  
argument

> What’s the page.method to change the background color of a DOM element?  
> I’m  
> trying to change the background color of a couple of styled
> 
> - 's when  
> an  
> Ajax link is clicked.
> 
> Thanks,  
> David

---

<div class="post-metadata">

**Author:** ![davidjrice](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@davidjrice](https://www.ruby-forum.com/u/davidjrice)\
**Post date:** [August 15, 2006, 2:18pm UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806/5 "2006-08-15T14:18:44Z")

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Try this:

page.call ‘Element.addClassName’, ‘element\_id’, ‘class\_name’

Zack

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<div class="post-metadata">

**Author:** ![davidjrice](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@davidjrice](https://www.ruby-forum.com/u/davidjrice)\
**Post date:** [August 9, 2006, 12:11am UTC](https://www.ruby-forum.com/t/rjs-change-background-color/101806/6 "2006-08-09T00:11:42Z")

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page \<\< “Element.addClassName(element, className)”

David R. wrote:

> Thanks for the answer, Zack.
> 
> I’m not sure quite how to use that method, though. Fitting  
> Element.addClassName into an RJS file won’t work, and  
> page.add\_class\_name"id of element", “class name” throws an error  
> saying AddClassName is not  
> defined.
> 
> - David