[RFR] Add option to make ReferenceInput choices lazy

[ValentinH]

This is actually implementing a similar feature than the one requested in #5898 but for <ReferenceInput.

Why

The goal is to be able to control when the useGetList is enabled to avoid over-fetching the choices. In our application, we have a user autocomplete component and, as we have hundred of thousands of possible choices, we only want to start showing/fetching the choices if the user inputs at least 2 characters.

Solution

This PR introduces an isEnabled option that is an optional function we use to set the enabled option of the useGetList(). This function is passed the filterValues array.

Example of usage:

<ReferenceInput
  label="example"
  reference="users"
  source="user"
  isEnabled={({ q }) => {
    return !!q && q.length > 2
  }}
>
  <AutocompleteInput ... />
</ReferenceInput>

Alternatives

Today, in order to work-around this, we pass a permanent filter filter={{ is_autocomplete: true }} that we use on our backend api to return early to avoid hitting the DB. However, we are still making calls for nothing.

---

I also looked to add a similar prop for the ReferenceArrayInput but, as it's using useGetMatching, it's a bit more complex.

If you think this option makes sense, I'd be happy to dig more to also add support for it for the ReferenceArrayInput.

[fzaninotto]

Nice! This will be a welcome addition.

You need to add unit tests and documentation to have this PR ready to merge.

[fzaninotto]

This won't work when isEnabled isn't set

[ValentinH]

I actually relied on the enabled option default value being true. However, I can make it true explicitly if you think this is clearer.

[ValentinH]

OK, happy that you like it. I'll add the tests and docs then.

What do you think about my comments regarding ReferenceArrayInput ?

[fzaninotto]

Nice! Feel free to do the same for ReferencearrayInput, too.

[ValentinH]

From what I see useReferenceArrayInputController() uses useGetMatching() and the enabled option is actually not working properly there: when the enabled flag is false, the loading prop is stuck to true which will show the loading indicator. I need to dig more into this and probably fix the enabled prop behaviour for useGetMatching.

If you agree, I'll do this in a follow-up PR.

Edit: I've a working solution, I'll push it later today 🙂

[ValentinH]

I just pushed the support for the enableGetChoices prop on the ReferenceArrayInput.

One small thing that I find misleading is that the filterValues always contain the q param for ReferenceInput but not for ReferenceArrayInput. This enforces checking for q being present in the ReferenceArrayInput enableGetChoices function:

Do you think this is something that should be taken care of or is fine like this?

[ValentinH]

@fzaninotto do you think this PR is ready to be merged or is it still missing something?

[ValentinH]

Why is this being closed?

[fzaninotto]

This PR was automatically closed by GitHub, I'm reopening it. Sorry for the noise.

[ValentinH]

I think this PR was closed again by Github. I believe it is still valid.

[fzaninotto]

You're right, I'm reopening it.

[dgkm]

It's a great feature. Any idea in which release this PR is getting merged and will be available?

Requested changes have been applied

[ValentinH]

Thanks for merging this PR! 🎉

[djhi]

Thanks!