Deterministic ordering of corpus fields

[BeritJanssen]

Is your feature request related to a problem? Please describe.
The order of fields used to be determined by the ordering in the corpus definition. With the conversion to database corpora, this does not seem to be the case anymore, while there used to be a convention that the datefield was always the first filter to appear in the list.

Describe the solution you'd like
We might add an order field to the fields, which, for python corpora, might be set with a data migration, and for other corpora, might have the default of 0, giving the user the option to move fields up or down in the display.

Describe alternatives you've considered
We might also enforce ordering based on Python files, but for "database born" corpora, this is not a solution.

[lukavdplas]

We might add an order field to the fields, which, for python corpora, might be set with a data migration, and for other corpora, might have the default of 0, giving the user the option to move fields up or down in the display.

Django's order_with_respect_to does pretty much exactly what you describe here!

[BeritJanssen]

Ah, noice! Didn't know of that yet, nice sugar around adding your own ordering field.

[lukavdplas]

Some more thoughts:

• The JSON and Python APIs for corpora both pass the fields as an ordered list/array, so the order in the database can be set from that definition.
• In the corpus creation form, we can say that, for now, the order of fields in the JSON is taken from the example CSV. (I suspect this is already the case in Feature/corpus form #1659) Eventually, it would be nice if the form also included controls to adjust the order.