Differentiate between a user skipping the rank question and consciously choosing the default order

[latin-panda]

Note: This is different from issue #294. This issue is about the question’s value (user input) held internally in the form.

Description
The current rank implementation is incomplete because there is no way to differentiate between a user skipping the question and consciously accepting the default order.

Additionally, rank questions need a way to clear their value and reset to the initial state.

Questions

• If a rank question is required, and the user has not reordered the options from their default order, should it be considered unanswered?

Additional Details
Both Collect and Enketo start with an empty answer and only populate the response when the user takes explicit action.
In line with this behavior, Enketo allows clearing a rank question’s value, resetting it to the initial disabled state.

To do:

• Research and determine priority
• Design a consistent user interface and experience for this empty state.
• Implement the empty state in <select>, <select1> and <odk:rank>.
• Automate tests to verify the UIUX

[latin-panda]

@eyelidlessness added good context here that relates to this issue more closely and that should be considered during design