src/Widgets/ActiveForm.php
public function run()
    {
        if (!empty($this->_fields)) {
            throw new InvalidCallException('Each beginField() should have a matching endField() call.');
        }

        $content = ob_get_clean();
        echo $this->htmlHlp->beginForm($this->action, $this->method, $this->options);
        echo $content;

        if ($this->enableClientScript) {
            $this->registerClientScript();
        }

        echo $this->htmlHlp->endForm();
    }
public function run()
    {
        if (!empty($this->_fields)) {
            throw new InvalidCallException('Each beginField() should have a matching endField() call.');
        }

        $content = ob_get_clean();
        echo $this->htmlHlp->beginForm($this->action, $this->method, $this->options);
        echo $content;

        if ($this->enableClientScript) {
            $this->registerClientScript();
        }

        echo $this->htmlHlp->endForm();
    }
Runs the widget.
This registers the necessary JavaScript code and renders the form open and close tags.
@throws InvalidCallException if `beginField()` and `endField()` calls are not matching.