BP_Button::backward_compatibility_args( array $r = array() )

	protected function backward_compatibility_args( $r = array() ) {
		// Array of deprecated arguments.
		$backpat_args = array(
			'wrapper', 'wrapper_class', 'wrapper_id',
			'link_href', 'link_class', 'link_id', 'link_rel', 'link_title'
		);

		foreach ( $backpat_args as $prop ) {
			if ( empty( $r[ $prop ] ) ) {
				continue;
			}

			$parent = $child = false;
			$sep    = strpos( $prop, '_' );

			// Check if this is an attribute.
			if ( false !== $sep ) {
				$child  = true;
				$parent = substr( $prop, 0, $sep );
			} else {
				$parent = $prop;
			}

			if ( 'wrapper' === $parent ) {
				$parent = 'parent';
			} else {
				$parent = 'button';
			}

			// Set element.
			if ( false === $child && empty( $r[ "{$parent}_element" ] ) ) {
				$r[ "{$parent}_element" ] = $r[ $prop ];

			// Set attributes.
			} elseif ( true === $child ) {
				$new_prop = substr( $prop, strpos( $prop, '_' ) +1 );
				if ( empty( $r[ "{$parent}_attr" ] ) ) {
					$r[ "{$parent}_attr" ] = array();
				}

				if ( empty( $r[ "{$parent}_attr" ][ $new_prop ] ) ) {
					$r[ "{$parent}_attr" ][ $new_prop ] = $r[ $prop ];
				}
			}
		}

		return $r;
	}