Using ODK 2 or modifying ODK Collect to be able to use dynamic select options

What is everyone’s opinion on modifying ODK Collect vs. using ODK 2 to achieve the following feature?
The use case is the following:
The select options will be a list of items.
If an item is not in the select options list, then the user will add a new item.
Now, on the following form that is collected by the user, the new item will be available in the select options.

Hi @Jefferson_Francisco!

Could you maybe tell us a little more about what you are trying to do here? Basically, are you trying to have an “other, specify” option? That then is in the select options? You can do something like this with ODK2, for example, we did household rosters and then allowed people to select the names of husbands, wives, parents, children, etc. in other questions. But I am not quite clear what the following form is for your case.

Best,
Caroline

Yes, it is like a situation where a user selects other.

If a user selects ‘other’ and then types text in a text field
Then, the select options would update after the user sends the form to the server for all users.

Also, how would one go about doing this in ODK 2?

I think you could do something like this with a linked form/table and queries:
https://docs.opendatakit.org/odk2/xlsx-converter-using/?highlight=subform#linked-tables
So if you had your main list of pre-existing options, and then someone picked other, you could have a list of existing (sync’d) others there to pick from, and if not on the list, you could add, so that once it’s sync’d others could use. This is a little unwieldy but possible.

Thanks! That is a good solution. I don’t think it’s too unwieldy.