kernel/lib/Form/Input.php
public function isClicked(string $sType) : bool
    {
        if ($this->getType() === 'submit' || $this->getType() === 'button') {

            if (isset($_POST[$this->getName()])) { return true; }
        }

        return false;
    }
public function isClicked(string $sType) : bool
    {
        if ($this->getType() === 'submit' || $this->getType() === 'button') {

            if (isset($_POST[$this->getName()])) { return true; }
        }

        return false;
    }
if the button is clicked

@access public
@param  string $sType type of input;
@return boolean