I need to filter the results on my search page to only return those with Item Type = Core. I know that it is possible to do this for the browse page by creating a plugin with a filter. Is there an equivalent filter to do this for the search page, or perhaps a simple URL argument to specify the item type?
You can't easily do that on the search page, since it's designed to work with many different kinds of records, most of which don't have an "item type" value.
If you want the search to only return Items anyway, maybe you should use the older Item-only search instead. It just runs through the browse page, so you use the same browse page methods for filtering or limiting the results.
Hmm, that's unfortunate. While I have the item type filter working on the browse page, the problem is that the keyword search on the browse page is not working and can only do exact searches. For example, this search url for "sloth" (http://jhepptest.library.jhu.edu/omeka/items/browse?search=sloth) returns the correct item, but this search url for "sloth skeleton" (http://jhepptest.library.jhu.edu/omeka/items/browse?search=sloth+skeleton) does not return anything.
Do you have any idea why the browse page is only doing exact searches? I've seen other omeka sites for which browse performs the keyword search correctly, but I can't figure out why it's not working in our case.