php/widgets/ButtonWidget.php
public function setTarget( $target ) {
		$this->target = is_string( $target ) ? $target : null;

		if ( $this->target !== null ) {
			$this->button->setAttributes( [ 'target' => $target ] );
		} else {
			$this->button->removeAttributes( [ 'target' ] );
		}

		return $this;
	}
public function setTarget( $target ) {
		$this->target = is_string( $target ) ? $target : null;

		if ( $this->target !== null ) {
			$this->button->setAttributes( [ 'target' => $target ] );
		} else {
			$this->button->removeAttributes( [ 'target' ] );
		}

		return $this;
	}
public function setTarget ( $ target ) { $ this -> target = is_string ( $ target ) ? $ target : null ; if ( $ this -> target !== null ) { $ this -> button -> setAttributes ( [ 'target' => $ target ] ) ; } else { $ this -> button -> removeAttributes ( [ 'target' ] ) ; } return $ this ; }
Set hyperlink target.

@param string|null $target Hyperlink target, null to remove
@return $this
Set hyperlink target .