We are starting with OpenDataKit and would like to create a select box / spinner which we can dynamically update without having to generate and upload a new XML file.
Is it possible to link a select box to an XML or JSON feed, and use that feed to generate the options in the select box?
Disclaimer: I'm one of the developers of Open Data Kit (ODK).
While creating this smarter select one is possible in Android, there is a bug in JavaROSA (the library that powers ODK's form processing) that will likely result in data loss. In the case of a select1, the value you save will be discarded silently the next time you reload the saved instance.
Fixing this problem in JavaROSA is a good first step.