Optimistic mode

[fzaninotto]

Problem

The undoable mode is optimistic AND undoable. React-admin offers no way to use the dataProvider in an optimistic and non-unduable way.

Solution

Replace the 'undoable' boolean option in useDataProvider by a fetch mode the can be one of 'regular', 'optimistic', and 'undoable'. Implement that fetch mode in useDataProvider.

Closes #5133, supersedes #5258

Example usage

const [updateMany, { loading }] = useUpdateMany(
        resource,
        selectedIds,
        { views: 0 },
        {
            action: CRUD_UPDATE_MANY,
            onSuccess: () => {
                notify('ra.notification.updated', 'info', {
                    smart_count: selectedIds.length,
                }); // note that the notification isn't undoable
                unselectAll(resource);
            },
            onFailure: error =>
                notify(
                    typeof error === 'string'
                        ? error
                        : error.message || 'ra.notification.http_error',
                    'warning'
                ),
            mode: 'optimistic', // <= that's what's new
        }
    );

Tasks

• Proof of concept
• Improve naming
• Add documentation
• Add unit tests

[djhi]

Looks pretty good!

[djhi]

Way better!

[fzaninotto]

Switching to RFR

[djhi]

Awesome :)