protected function evalExpression()
    {
        $this->log("Evaluating PHP expression: " . $this->expression, $this->logLevel);
        if (!StringHelper::endsWith(';', trim($this->expression))) {
            $this->expression .= ';';
        }

        if ($this->returnProperty !== null) {
            $retval = null;
            eval('$retval = ' . $this->expression);
            $this->project->setProperty($this->returnProperty, $retval);
        } else {
            eval($this->expression);
        }
    }