) {
							return $matches[0];
						}
					}

					if ( ! is_callable( $cb ) ) {
						return $matches[0];
					}

					$args   = isset( $matches[2] ) ? ltrim( $matches[2], '|' ) : false;
					$config = isset( $matches[3] ) ? json_decode( $matches[3], true ) : false;

					// Store the initial configs
					$initial_fallback = $this->get_fallback();
					$initial_context  = $this->get_macros_context();
					$initial_before   = $this->get_before();
					$initial_after    = $this->get_after();

					// Reset the configs except macros context.
					$this->set_fallback( null );
					$this->set_before( null );
					$this->set_after( null );

					// Set the config of current macro
					if ( $config ) {
						
						if ( ! empty( $config['context'] ) ) {
							$this->set_macros_context( $config['context'] );
						}

						if ( ! Jet_Engine_Tools::is_empty( $config, 'fallback' ) ) {
							$this->set_fallback( $config['fallback'] );
						}

						if ( ! Jet_Engine_Tools::is_empty( $config, 'before' ) ) {
							$this->set_before( $config['before'] );
						}

						if ( ! Jet_Engine_Tools::is_empty( $config, 'after' ) ) {
							$this->set_after( $config['after'] );
						}

					}
					
					$result   = call_user_func( $cb, $field_value, $args );
					$fallback = $this->get_fallback();
					$before   = $this->get_before();
					$after    = $this->get_after();

					$is_empty_result = empty( $result );

					/*
					 * If the result of macro is `not-found` or array( 'not-found' )
					 * and the fallback value is not empty, then the fallback value is returned.
					 *
					 * See: https://github.com/Crocoblock/issues-tracker/issues/3243
					 */
					if ( ! $is_empty_result ) {
						$is_not_found_result = ( ( is_array( $result ) && in_array( 'not-found', $result ) ) || ( ! is_array( $result ) && 'not-found' === $result ) );

						if ( $is_not_found_result && ! Jet_Engine_Tools::is_empty( $fallback ) ) {
							$is_empty_result = true;
						}
					}

					if ( ! $is_empty_result ) {

						if ( is_array( $result ) ) {
							$result = implode( ',', $result );
						}

						if ( $before ) {
							$result = $before . $result;
						}

						if ( $after ) {
							$result .= $after;
						}

					} elseif ( ! Jet_Engine_Tools::is_empty( $fallback ) ) {
						$result = $fallback;
					}

					// Set the initial configs
					$this->set_fallback( $initial_fallback );
					$this->set_macros_context( $initial_context );
					$this->set_before( $initial_before );
					$this->set_after( $initial_after );

					return $result;

				}, $string
			);

		}

	}

}