WordPress at a glance
function is not described

rest_validate_value_from_schema() WP 4.7.0

Validate a value based on a schema.

No Hooks.

Return

true|WP_Error.

Usage

rest_validate_value_from_schema( $value, $args, $param );
$value(mixed) (required)
The value to validate.
$args(array) (required)
Schema array to use for validation.
$param(string)
The parameter name, used in error messages.

Changelog

Since 4.7.0 Introduced.
Since 4.9.0 Support the "object" type.
Since 5.2.0 Support validating "additionalProperties" against a schema.
Since 5.3.0 Support multiple types.
Since 5.4.0 Convert an empty string to an empty object.
Since 5.5.0 Add the "uuid" and "hex-color" formats. Support the "minLength", "maxLength" and "pattern" keywords for strings. Support the "minItems", "maxItems" and "uniqueItems" keywords for arrays. Validate required properties.
Since 5.6.0 Support the "minProperties" and "maxProperties" keywords for objects. Support the "multipleOf" keyword for numbers and integers. Support the "patternProperties" keyword for objects. Support the "anyOf" and "oneOf" keywords.

Code of rest_validate_value_from_schema() WP 5.7.2

<?php
function rest_validate_value_from_schema( $value, $args, $param = '' ) {
	if ( isset( $args['anyOf'] ) ) {
		$matching_schema = rest_find_any_matching_schema( $value, $args, $param );
		if ( is_wp_error( $matching_schema ) ) {
			return $matching_schema;
		}

		if ( ! isset( $args['type'] ) && isset( $matching_schema['type'] ) ) {
			$args['type'] = $matching_schema['type'];
		}
	}

	if ( isset( $args['oneOf'] ) ) {
		$matching_schema = rest_find_one_matching_schema( $value, $args, $param );
		if ( is_wp_error( $matching_schema ) ) {
			return $matching_schema;
		}

		if ( ! isset( $args['type'] ) && isset( $matching_schema['type'] ) ) {
			$args['type'] = $matching_schema['type'];
		}
	}

	$allowed_types = array( 'array', 'object', 'string', 'number', 'integer', 'boolean', 'null' );

	if ( ! isset( $args['type'] ) ) {
		/* translators: %s: Parameter. */
		_doing_it_wrong( __FUNCTION__, sprintf( __( 'The "type" schema keyword for %s is required.' ), $param ), '5.5.0' );
	}

	if ( is_array( $args['type'] ) ) {
		$best_type = rest_handle_multi_type_schema( $value, $args, $param );

		if ( ! $best_type ) {
			return new WP_Error(
				'rest_invalid_type',
				/* translators: 1: Parameter, 2: List of types. */
				sprintf( __( '%1$s is not of type %2$s.' ), $param, implode( ',', $args['type'] ) ),
				array( 'param' => $param )
			);
		}

		$args['type'] = $best_type;
	}

	if ( ! in_array( $args['type'], $allowed_types, true ) ) {
		_doing_it_wrong(
			__FUNCTION__,
			/* translators: 1: Parameter, 2: The list of allowed types. */
			wp_sprintf( __( 'The "type" schema keyword for %1$s can only be one of the built-in types: %2$l.' ), $param, $allowed_types ),
			'5.5.0'
		);
	}

	switch ( $args['type'] ) {
		case 'null':
			$is_valid = rest_validate_null_value_from_schema( $value, $param );
			break;
		case 'boolean':
			$is_valid = rest_validate_boolean_value_from_schema( $value, $param );
			break;
		case 'object':
			$is_valid = rest_validate_object_value_from_schema( $value, $args, $param );
			break;
		case 'array':
			$is_valid = rest_validate_array_value_from_schema( $value, $args, $param );
			break;
		case 'number':
			$is_valid = rest_validate_number_value_from_schema( $value, $args, $param );
			break;
		case 'string':
			$is_valid = rest_validate_string_value_from_schema( $value, $args, $param );
			break;
		case 'integer':
			$is_valid = rest_validate_integer_value_from_schema( $value, $args, $param );
			break;
		default:
			$is_valid = true;
			break;
	}

	if ( is_wp_error( $is_valid ) ) {
		return $is_valid;
	}

	if ( ! empty( $args['enum'] ) ) {
		$enum_contains_value = rest_validate_enum( $value, $args, $param );
		if ( is_wp_error( $enum_contains_value ) ) {
			return $enum_contains_value;
		}
	}

	// The "format" keyword should only be applied to strings. However, for backward compatibility,
	// we allow the "format" keyword if the type keyword was not specified, or was set to an invalid value.
	if ( isset( $args['format'] )
		&& ( ! isset( $args['type'] ) || 'string' === $args['type'] || ! in_array( $args['type'], $allowed_types, true ) )
	) {
		switch ( $args['format'] ) {
			case 'hex-color':
				if ( ! rest_parse_hex_color( $value ) ) {
					return new WP_Error( 'rest_invalid_hex_color', __( 'Invalid hex color.' ) );
				}
				break;

			case 'date-time':
				if ( ! rest_parse_date( $value ) ) {
					return new WP_Error( 'rest_invalid_date', __( 'Invalid date.' ) );
				}
				break;

			case 'email':
				if ( ! is_email( $value ) ) {
					return new WP_Error( 'rest_invalid_email', __( 'Invalid email address.' ) );
				}
				break;
			case 'ip':
				if ( ! rest_is_ip_address( $value ) ) {
					/* translators: %s: IP address. */
					return new WP_Error( 'rest_invalid_ip', sprintf( __( '%s is not a valid IP address.' ), $param ) );
				}
				break;
			case 'uuid':
				if ( ! wp_is_uuid( $value ) ) {
					/* translators: %s: The name of a JSON field expecting a valid UUID. */
					return new WP_Error( 'rest_invalid_uuid', sprintf( __( '%s is not a valid UUID.' ), $param ) );
				}
				break;
		}
	}

	return true;
}