Pass through refresh property to data provider?

[yelworc]

Is your feature request related to a problem? Please describe.
When working with API resources in react-admin (e.g. displaying objects in a List view), changes made through another client are not visible. Clicking the "refresh" icon in the title bar does not help because of HTTP caching. The only way to see recent changes (beyond waiting for the cached responses to expire) is clearing the browser cache.

Describe the solution you'd like
I noticed there is already a refresh property in some CRUD actions (e.g. crudGetOne), so I was wondering if it would make sense to add that to all those actions, and pass it through to the data provider (e.g. in params). The provider could then set HTTP headers to bypass the cache (Cache-Control: must-revalidate, I suppose).

Describe alternatives you've considered
Haven't really thought about alternative solutions yet, but totally open to suggestions.

If the above idea sounds reasonable, and would be a suitable first contribution (not touching too many parts of the codebase, etc), I'd be up for working on a PR.

[fzaninotto]

The refresh property in actions tells react-admin to refresh the view, not to pass a refresh to the dataProvider. It's different semantics, and besides, it's been removed in 3.0.

I don't see how react-admin could pass that information to the dataProvider. React-admin can't guess your caching policy. In my opinion, it's your job to write a dataProvider that sends a must-revalidate after a PUT, a POST or a DELETE on a resource.

So I'm closing it as it can be solved in userland (in your dataProvider).

[yelworc]

Hmm… your approach (revalidate after previous non-idempotent requests) only applies to the scenario where something was changed in "this" instance of react-admin. The more general case, where data has been modified through any other means, can't be solved that way.

You're totally right that react-admin can't guess caching policies, but when the user explicitly expresses they want to see up-to-date data (by clicking the refresh icon), I think it would make sense to pass this intent to the data provider somehow.

I agree that the refresh prop in CRUD actions should not be used for this purpose, as it has a different meaning.

[fzaninotto]

In react-admin, the path between the click on Refresh and the actual queries in the data provider takes many, many steps, and passing parameters through these steps isn't possible. So I suggest you solve this in userland, by implementing your own RefreshButton that stores a boolean in sessionStorage to force refresh, and the dataProvider can read this boolean before making requests.

[yelworc]

Alright – thanks for taking the time to explain!