- introduces support for graphql_description_after when using register_graphql_acf_field_type, allowing for a string or callback to be passed that will append a string to the description which is populated by the field graphql_description or instructions field.

- implements this on the DatePicker and DateTimePicker field types to show that the string will be output in RFC3339 format
- updates the description of the startDate and endDate fields of the ACFE_Date_Range type to include a link to the RFC3339 spec

Author: jasonbahl

src/FieldConfig.php

@@ -135,6 +135,9 @@ protected function is_supported_field_type(): bool {
 	 */
 	public function get_field_description(): string {
 
+		$graphql_field_type = $this->get_graphql_field_type();
+		$field_type_config = ( $graphql_field_type instanceof AcfGraphQLFieldType ) ? $graphql_field_type->get_config() : [];
+
 		// Use the explicit graphql_description, if set
 		if ( ! empty( $this->acf_field['graphql_description'] ) ) {
 			$description = $this->acf_field['graphql_description'];
@@ -153,6 +156,15 @@ public function get_field_description(): string {
 			);
 		}
 
+		if ( isset( $field_type_config['graphql_description_after'] ) ) {
+
+			if ( is_callable( $field_type_config['graphql_description_after'] ) ) {
+				$description .= ' ' . call_user_func( $field_type_config['graphql_description_after'], $this );
+			} else {
+				$description .= ' ' . $field_type_config['graphql_description_after'];
+			}
+		}
+
 		return $description;
 	}
 

src/FieldType/DatePicker.php

@@ -13,6 +13,13 @@ public static function register_field_type(): void {
 			'date_picker',
 			[
 				'graphql_type' => 'String',
+				// Apply a description to be appended to the field description.
+				// @todo: consider removing when CustomScalar types are supported along with the @specifiedBy directive
+				'graphql_description_after'  => function( FieldConfig $field_config ) {
+					$field_type = $field_config->get_acf_field()['type'] ?? null;
+
+					return '(' . sprintf( __( 'ACF Fields of the %s type return a date string in the format `YYYYMMDD` according to the RFC3339 spec: https://datatracker.ietf.org/doc/html/rfc3339.', 'wp-graphql-acf' ), $field_type ) . ')';
+				},
 				'resolve'      => static function ( $root, $args, $context, $info, $field_type, FieldConfig $field_config ) {
 					$value = $field_config->resolve_field( $root, $args, $context, $info );
 

src/FieldType/DateTimePicker.php

@@ -14,6 +14,13 @@ public static function register_field_type(): void {
 			'date_time_picker',
 			[
 				'graphql_type' => 'String',
+				// Apply a description to be appended to the field description.
+				// @todo: consider removing when CustomScalar types are supported along with the @specifiedBy directive
+				'graphql_description_after'  => function( FieldConfig $field_config ) {
+					$field_type = $field_config->get_acf_field()['type'] ?? null;
+
+					return '(' . sprintf( __( 'ACF Fields of the %s type return a date string in the format `YYYYMMDD` according to the RFC3339 spec: https://datatracker.ietf.org/doc/html/rfc3339.', 'wp-graphql-acf' ), $field_type ) . ')';
+				},
 				'resolve'      => static function ( $root, $args, $context, $info, $field_type, FieldConfig $field_config ) {
 					$value = $field_config->resolve_field( $root, $args, $context, $info );
 

src/FieldType/FlexibleContent.php

@@ -73,7 +73,9 @@ static function ( $field ) use ( $layout ) {
 								)
 							);
 
-							$layout['sub_fields'] = array_merge( $sub_fields, $layout['sub_fields'] );
+							$layout_sub_fields = ! empty( $layout['sub_fields'] ) && is_array( $layout['sub_fields'] ) ? $layout['sub_fields'] : [];
+
+							$layout['sub_fields'] = array_merge( $sub_fields, $layout_sub_fields );
 
 							$layouts[] = $layout;
 						}

src/ThirdParty/AcfExtended/AcfExtended.php

@@ -339,12 +339,12 @@ public function register_initial_types(): void {
 					'startDate' => [
 						// @todo: DATETIME Scalar
 						'type'        => 'String',
-						'description' => __( 'The start date of a date range returned as an RFC 3339 time string', 'wpgraphql-acf' ),
+						'description' => __( 'The start date of a date range returned as an RFC 3339 time string (https://datatracker.ietf.org/doc/html/rfc3339)', 'wpgraphql-acf' ),
 					],
 					'endDate'   => [
 						// @todo: DATETIME Scalar
 						'type'        => 'String',
-						'description' => __( 'The start date of a date range RFC 3339 time string', 'wpgraphql-acf' ),
+						'description' => __( 'The start date of a date range RFC 3339 time string (https://datatracker.ietf.org/doc/html/rfc3339)', 'wpgraphql-acf' ),
 					],
 				],
 			]