# How to overwrite a method?

**URL:** <https://www.ruby-forum.com/t/how-to-overwrite-a-method/152787>\
**Category:** Rails\
**Created:** [November 7, 2008, 12:15pm UTC](https://www.ruby-forum.com/t/how-to-overwrite-a-method/152787 "2008-11-07T12:15:28Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![ss\_1982](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@ss\_1982](https://www.ruby-forum.com/u/ss_1982)\
**Post date:** [November 7, 2008, 12:15pm UTC](https://www.ruby-forum.com/t/how-to-overwrite-a-method/152787/1 "2008-11-07T12:15:28Z")

</div>

Hi,

The following file within rails  
/activeresource/lib/active\_resource/formats/xml\_format.rb

Has the method  
def extension  
“xml”  
end

How can I overwrite this so that it returns PHP without editing any core  
file?

Thanks

---

<div class="post-metadata">

**Author:** ![ss\_1982](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/96bed5/32.png) [@ss\_1982](https://www.ruby-forum.com/u/ss_1982)\
**Post date:** [November 7, 2008, 12:17pm UTC](https://www.ruby-forum.com/t/how-to-overwrite-a-method/152787/2 "2008-11-07T12:17:59Z")

</div>

On 7 Nov 2008, at 11:15, Scott A S wrote:

> How can I overwrite this so that it returns PHP without editing any  
> core  
> file?

just reopen that class  
class WhateverItIs  
def extension  
“php”  
end  
end