What are REST API Fields?
REST API fields provide a powerful mechanism for extending and customizing WordPress REST API responses with additional data and metadata.
Core Functionality
// Register a new field to the posts endpoint
register_rest_field( 'post', 'custom_meta', array(
'get_callback' => 'get_custom_meta_callback',
'update_callback' => 'update_custom_meta_callback',
'schema' => null
));
Key Features
- Dynamic field registration
- Custom data retrieval
- Flexible schema definition
- Read and write capabilities
Advanced Usage
Extend REST API responses with complex metadata, computed fields, and dynamic content transformations.
function advanced_field_callback( $object, $field_name, $request ) {
// Complex field generation logic
return generate_dynamic_metadata( $object );
}