php/widgets/ButtonInputWidget.php
public function setLabel( $label ) {
		if ( $this->useInputTag ) {
			// Discard non-plaintext labels
			if ( !is_string( $label ) ) {
				$label = '';
			}

			$this->input->setValue( $label );
		}

		return $this->setLabelElementLabel( $label );
	}
public function setLabel( $label ) {
		if ( $this->useInputTag ) {
			// Discard non-plaintext labels
			if ( !is_string( $label ) ) {
				$label = '';
			}

			$this->input->setValue( $label );
		}

		return $this->setLabelElementLabel( $label );
	}
public function setLabel ( $ label ) { if ( $ this -> useInputTag ) { // Discard non-plaintext labels if ( ! is_string ( $ label ) ) { $ label = '' ; } $ this -> input -> setValue ( $ label ) ; } return $ this -> setLabelElementLabel ( $ label ) ; }
Set label value.

Overridden to support setting the 'value' of `<input>` elements.

@param string|null $label Label text
@return $this
Set label value .