How to properly use oneOf and anyOf in Rest Schema?

Question

I have asked this before at Stackoverflow, now I'm here to be more wp specific and bring more context - as I did some advance on this.

Seeing this use of oneOf has made me change my schema to this structure below:

array(
    'type'         => 'object',
    'show_in_rest' => array(
        'schema' => array(
            'type'       => 'object',
            'properties' => array(
                'tipo' => array(
                    'type'  => 'string',
                    'name'  => 'tipo',
                    'enum'  => array(
                        '...',
                    ),
                ),
                'data' => array(
                    'type'   => 'array',
                    'items'  => array(
                        'type'  => 'object',
                        'oneOf' => array(
                            array(
                                'properties'           => array(
                                    'dia'         => array(
                                        'type'        => 'string',
                                        'name'        => 'dia',
                                    ),
                                    'hora_inicio' => array(
                                        'type'        => 'string',
                                        'name'        => 'hora_inicio',
                                    ),
                                    'hora_fim'    => array(
                                        'type'        => 'string',
                                        'name'        => 'hora_fim',
                                    ),
                                ),
                                'name'                 => 'data_unica',
                                'title'                => 'Data única',
                            ),
                            array(
                                'properties'           => array(
                                    'periodicidade' => array(
                                        'type'        => 'string',
                                        'name'        => 'periodicidade',
                                        'enum'        => array(
                                            '...'
                                        ),
                                    ),
                                    'dia_inicial'   => array(
                                        'type'        => 'string',
                                        'name'        => 'dia_inicial',
                                    ),
                                    'dia_final'     => array(
                                        'type'        => 'string',
                                        'name'        => 'dia_final',
                                    ),
                                    'hora_inicial'  => array(
                                        'type'   => 'string',
                                        'name'   => 'hora_inicial',
                                    ),
                                    'hora_final'    => array(
                                        'type'   => 'string',
                                        'name'   => 'hora_final',
                                    ),
                                ),
                                'name'                 => 'data_corrente',
                                'title'                => 'Data corrente',
                            ),
                        ),
                    ),
                ),
            ),
        ),
    ),
);

The request is:

meta: {
    "datas": {
        "tipo": "UNICA",
        "data": [{
            "dia": "2022-10-21",
            "hora_inicio": "",
            "hora_fim": ""
        }]
    }
}

And the response:

{
    "code": "rest_additional_properties_forbidden",
    "message": "dia is not a valid property of Object.",
    "data": {
        "status": 400
    }
}

What am I doing wrong?

Answer 1

After some testing in WordPress v6.0.1, it seemed that:

1. We need to set the (default/initial) type of the data.items to null instead of object. (and yes, the type must be set, or else the API response would be invalidated with many "undefined index" notices)

2. For each item, i.e. an array in the oneOf or anyOf, set the type to object.

So your data schema should look like this, but I purposely used anyOf (see explanation below):

'data' => array(
    'type'  => 'array',
    'items' => array(
        'type'  => null,
        'anyOf' => array(
            array(
                'type'       => 'object',
                'properties' => array( ... ),
                'title'      => 'Data única',
            ),
            array(
                'type'       => 'object',
                'properties' => array( ... ),
                'title'      => 'Data corrente',
            ),
        ), // end anyOf
    ), // end items
), // end data

And the reason why I did not use oneOf, is because it caused an error with the code rest_one_of_multiple_matches and the message meta.datas[data][0] matches Data única and Data corrente, but should match only one.

• You could avoid that issue by using unique schemas, e.g. add enum to the dia's schema or change the hora_inicio's type to number, but that is up to you to decide.