Did you managed to solve this one?
The built in URL picker is only supported for the user interface and not for public web sites or intranets so you will have to add another file upload mechanism. If I misunderstood you and you want to add a custom UI extension where a user should be able to get a URL picker, there is currently no good support for this but it's something that we have in our backlog.
Well I was looking for something like episerver:inputpagereference but for contentreference instead. Can you point me in the right direction to build an own picker for this since you just now dont have any support for this?
I took a look on the code used to create the page picker a few weeks ago to see if it would be simple to copy paste this code and just tweak it to work with any content. Unfortunately, it's very complex with a lot of components and logic that's not needed if you just want to be able to pick a single item. So if I had to do this, I would probably go for something more like a seach box with auto-suggestion support instead of a tree to create a good user experience instead of trying to get an entire tree-popup history working.
I am extending the available properties for a user within my site based on the Tore's comments on a forum post here:
Its working great but I want to allow the users to upload an avatar of themselves, I could just have a simple text field and add the path to the image through that but its not very user friendly. I was wondering if there is anyway to have an input just like the Url Property you can add to a page type, preferably with the UIHint(UIHint.Image) set on it as well. Does anyone know if this is possible?