src/Web/ClientProxy.php
public function showClientAlert($alertText)
    {        
        if ($this->isRpc) {
            $msg = addslashes($alertText);
            $this->_otherOutput[] = $this->callClientFunction("alert('" . $msg . "')");
        }
    }
public function showClientAlert($alertText)
    {        
        if ($this->isRpc) {
            $msg = addslashes($alertText);
            $this->_otherOutput[] = $this->callClientFunction("alert('" . $msg . "')");
        }
    }
Show popup an alert window on the client browser.
Encoded html string returns to browser, it'll be processed by client javascript.

@param string $alertText
@return void