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filter is not described

rest_(post_type)_collection_params filter-hook . WP 4.7.0

Filter collection parameters for the posts controller.

The dynamic part of the filter $this->post_type refers to the post type slug for the controller.

This filter registers the collection parameter, but does not map the collection parameter to an internal WP_Query parameter. Use the rest_{$this->post_type}_query filter to set WP_Query parameters.

Usage

add_filter( 'rest_(post_type)_collection_params', 'filter_function_name_8538', 10, 2 );
function filter_function_name_8538( $query_params, $post_type ){
	// filter...

	return $query_params;
}
$query_params(array)
JSON Schema-formatted collection parameters.
$post_type(WP_Post_Type)
Post type object.

Where the hook is called

WP_REST_Posts_Controller::get_collection_params()
rest_(post_type)_collection_params
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php 2534
return apply_filters( "rest_{$this->post_type}_collection_params", $query_params, $post_type );

Where the hook is used (in WP core)

Does not used.