As I recently wrote, I have a new-found interest in ebooks (I also bought four new textbooks from O’Reilly using a BOGOF offer to pick up 97 Things Every Programmer Should Know, 97 Things Every Project Manager Should Know, Beautiful Code and The Art of Agile Development).
Aldiko has a built in browser for the feedbooks.com catalog, but also gives you the ability to add your own catalogs. A friend told me that Calibre, a popular ebook management programme, has a web interface which one of the other popular Android ebook readers (WordPlayer) could be pointed at in order to add custom catalogs. After a quick trial and a few Google searches, I realised that WordPlayer actually subscribes to an XML file hosted on http://localhost/calibre/stanza
Opening this file shows it to be Atom, where each entry is a small metadata container and the link element is used to reference the actual book and images that represent it, like this:
<link type="application/epub+zip" href="/get/epub/3"/>
<link rel="x-stanza-cover-image" type="image/jpeg" href="/get/cover/3"/>
<link rel="x-stanza-cover-image-thumbnail" type="image/jpeg" href="/get/thumb/3"/>
Another few searches showed this to be a draft specification called openpub. Aldiko supports this, so adding the /stanza URL to a custom catalog works there too! Voila, custom catalogs in Aldiko. Marvellous!
It should only require a tiny bit of work to write code that serves a catalog straight from the filesystem without the overhead of Calibre (which I found to be quite heavyweight). This is what I have started here.