# Howto: rebuild thumbnails in attachment\_fu

**URL:** <https://www.ruby-forum.com/t/howto-rebuild-thumbnails-in-attachment-fu/178690>\
**Category:** Rails\
**Created:** [November 9, 2009, 5:26pm UTC](https://www.ruby-forum.com/t/howto-rebuild-thumbnails-in-attachment-fu/178690 "2009-11-09T17:26:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![russellf](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/7bcc69/32.png) [@russellf](https://www.ruby-forum.com/u/russellf)\
**Post date:** [November 9, 2009, 5:26pm UTC](https://www.ruby-forum.com/t/howto-rebuild-thumbnails-in-attachment-fu/178690/1 "2009-11-09T17:26:49Z")

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I’ve just added a new thumbnail definition to a class that has  
attachments using attachment\_fu. Since this thumbnail definition didn’t  
exist when I uploaded pior images, they don’t have this thumbnail. I  
have been trying to figure out how to either load the image attachment  
and have it build the thumbnail. Does anyone know how to do this?

Thanks in advance.

Russell

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<div class="post-metadata">

**Author:** ![russellf](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/7bcc69/32.png) [@russellf](https://www.ruby-forum.com/u/russellf)\
**Post date:** [November 10, 2009, 2:06am UTC](https://www.ruby-forum.com/t/howto-rebuild-thumbnails-in-attachment-fu/178690/2 "2009-11-10T02:06:23Z")

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Here’s some example code from the Kete project ([http://kete.net.nz](http://kete.net.nz)):

[http://github.com/kete/kete/blob/master/lib/tasks/tools.rake](http://github.com/kete/kete/blob/master/lib/tasks/tools.rake) -  
starting at line 61

Cheers,  
Walter

On Tue, Nov 10, 2009 at 5:26 AM, Russell F.