Issues with useEmbedded = true

API Platform version(s) affected: 2.2.0

Description
When using the useEmbedded = true parameter with the HydraDataProvider fetching a nested resource is failing because the built URL is not valid (trying GET /[object%20Object])

How to reproduce
I have this .jsonld produced by my Api-platform APIs. There’s a resource Publisher (https://gist.github.com/seltzlab/dd9651b28b81ec35527cf01d060781bf#file-jsonld-L1291) that embeds a MediaType resource https://gist.github.com/seltzlab/dd9651b28b81ec35527cf01d060781bf#file-jsonld-L977

In he Publisher list view everything is fine, I can print the MediaType.name property without any issue

const PublishersList = props => (
    <List {...props} exporter={false}>
        <Datagrid>
            <FieldGuesser source="name" />
            <TextField source="type.name" label="Media type" sortable={false} />
            <FieldGuesser source="country_code" sortable={false} />
            <EditButton />
        </Datagrid>
    </List>
);

But within the edit view the Autocomplete gets no value and I see the provider trying to retrieve GET /[object%20Object]

export default function PublisherEdit(props) {
    return <Edit {...props} actions={<React.Fragment />}>
        <SimpleForm variant="outlined">
            <Typography variant="h5">Edit publisher</Typography>
            <TextInput source="name" fullWidth />
            <ReferenceInput label="Media type" reference="media-types" source="type">
                <AutocompleteInput optionValue="id" optionText="name" options={{variant: "outlined"}} fullWidth pagination={false}/>
            </ReferenceInput>
            <TextInput source="country_code" label="Country code (2 chars)" />
        </SimpleForm>
    </Edit>;
}

Additional Context
Digging into the hydraDataProvider I’ve seen that into convertReactAdminRequestToHydraRequest the params.id is an object itself. Without the useEmbedded the edit view looks working fine, while the list is not.

[seltzlab]

@alanpoulain great thanks, it works. I had to change the format function with

 format={v => v !== null && typeof v === 'object' && v.hasOwnProperty('@id') ? v['@id'] : v}

because if v is null it fails with Cannot read property '@id' of null

[alanpoulain]

I’ve added a documentation here: https://github.com/api-platform/docs/pull/1116.

Basically you need to add:

format={v => v['@id'] ?? v}

to your ReferenceInput.