bibliographic citation customization

It would be nice to customize the bibliographic citation of an item to show where the image came from (the College Archives where the original resides) instead of just referencing the online exhibit. Is there any way to do this?

Thank you!

To customize the citation of an item, you will need to do some code hacking.

If you are comfortable with PHP, you can copy the item_citation() function (in application/helpers/NewThemeFunctions.php) to your theme's custom.php file, change the name of the function to something different (like my_custom_citation, for example).

And then you would modify that to output a different citation style and call it instead of item_citation() in your public theme.

Of course, it would be much nicer if someone wrote a plugin to do this with pre-existing citation formats.

Seems that this file is no longer part of the current build (December 2011).


There is a call to item_citation() in theme file items/show.php which seems to have replaced custom.php.

The item_citation() function now resides in


Just to update this thread, since Omeka 1.4 you no longer need to copy the item_citation function into your own theme's custom.php file. You can filter the output of this, using the item_citation filter, with your own custom function.

Where does this function live in 2.O?

It's still in the the item_citation filter. A simple plugin similar to the example in the documentation will do the trick.

This is where it's clear to me how little I understand. I don't have the big picture on how the Omeka functions and filters and helpers and whatever you call them are organized.
I took a php class I have had success modifying the public Omeka site by putting copies of php files in the appropriate themes folder.
I guess my specific question is what file and what directory is item_citation_filter in?

Filters are a little more involved than functions. Basically, they are a way to modify certain default behaviors and outputs from Omeka. So there's not a specific function to look for. Instead, they are a way of tapping into content coming from Omeka, modifying it, then letting that content move on to other plugins that modify it.

If you look in the COinS plugin directory, you'll see a basic structure. All you will need is to mimic the CoinsPlugin.php file and the plugin.ini file. The example plugin from the documentation I linked to should also help.

After reading this thread I'm still unsure how to edit what appears on the page for citation. I have a group of 84 papers in a collection that have both authors and editors but I don't know how to get the editor's names to appear along with the authors.