ReferenceInput : using GET_ONE instead of GET_MANY like it was done in admin-on-rest

Question

I am migrating from admin-on-rest to react-admin

Using the exact same Edit/SimpleForm/ReferenceInput combination, the behavior is different between admin-on-rest (seems to use GET_ONE) and react-admin (seems to use GET_MANY)

The problem is that my backend API does not support the GET_MANY

Does this mean that I have to modify my data provider to somehow transform a GET_MANY into multiple GET_ONE calls ?

If so, could you provide a basic example to do that.

Please note that this could be part of the documentation at https://marmelab.com/react-admin/Inputs.html#referenceinput since I suppose this is not uncommon

Answer 1

Waiting for a definitive answer to my question, here is what I did in my data provider based on https://marmelab.com/react-admin/DataProviders.html#example-request-processing :

const convertRESTRequestToHTTP = (type, resource, params) => new Promise((resolve, reject) => {
    let url = '';
    const options = {};
    switch (type) {
        /* see other cases in the doc */
        case GET_MANY: {
            //our API does not support GET_MANY
            //=> we fallback to GET_ONE if there is a single id,
            //   otherwise we throw an error
            // also see convertHTTPResponseToREST to transform the JSON
            if (params.ids.length === 1) {
              url = `${apiUrl}/${resource}/${params.ids[0]}`;
              break;
            }
            throw new Error('the API does not support GET_MANY')
        }
    }
    resolve({ url, options });
});

const convertHTTPResponseToREST = (response, type, resource, params) => {
    const { json } = response;
    switch (type) {
        /* see other cases in the doc */
        case GET_MANY:
            //see explanantion in convertRESTRequestToHTTP
            if (params.ids.length !== 1) {
              throw new Error('the API does not support GET_MANY')
            }
            return { data: [json] };            
    }
};