demo

class DynamicLayoutHandler(object):
    def _check_layout(self):
        if self.layout is None:
            raise FormHelpersException("You need to set a layout in your FormHelper")

    def _check_layout_and_form(self):
        self._check_layout()
        if self.form is None:
            raise FormHelpersException("You need to pass a form instance to your FormHelper")

    def all(self):
        """
        Returns all layout objects of first level of depth
        """
        self._check_layout()
        return LayoutSlice(self.layout, slice(0, len(self.layout.fields), 1))