Reference areas from a log

[mstenta]

Logs in farmOS can be linked to farm areas. For example: an observation of pest pressure in a specific field.

This feature request is to add the ability to reference areas from a log.

There are a few considerations to figure out with this:

• We will need to fetch a list of existing areas from farmOS and store them locally, so that they can be presented as available options to choose from. This will require a separate AJAX request - probably when the app is first initialized (after login credentials are saved for the first time). These areas will need to be stored locally so that they are available as options when you are offline. There will also need to be some way of auto-updating them from time to time - because they may change in farmOS (outside of the app). This may need to be a separate issue in itself: "Maintain a list of farm areas internally"
• The "widget" for selecting the areas in the log form will need some thought. A simple HTML multi-select field type would be an easy first step, but if you have a large list of areas it can become unwieldy. I say we start with that, though, and create a followup issue if/when necessary. The mobile UI for multi-select is actually pretty good (easier than holding down "Shift" on a desktop, IMO).

[mstenta]

Broke out the first bullet point to a separate issue: #23

That is really a prerequisite of this feature request.

[jgaehring]

Resolved as of 10616fa

[mstenta]

(Transferring all issues from old repository. See #92)