Unfortunately the documentation for WordPress’ XML-RPC API only covers the WordPress specific extensions. As such if you want to do anything useful you’ll have to seek help else where. Perhaps the most important thing to note is that WordPress supports Metaweblog a proper open standard.
During my google’ing I came accross several helpful links:
- Overview of MetaWeblog
- Example newPost call
- IXR a very polished PHP XML-RPC lib
- Patch to expose Featured image to xmlrpc api
Attaching an image to a post:
One thing that was absolutely un-documented was a method to attach an image to a post. After some digging I found attach_uploads() which is a function that wordpress calls every time a post is created or edited over xml-rpc. What it does is search through the list of un-attached media objects and see if the new/edited post contains a link to them. Since I was trying to attach images so that the theme’s gallery would use them I didn’t necessarily want to link to the images within the post, nor did I want to edit wordpress. So what I ended up doing was including the image url within an html comment.