web/core/block.py
def _observe_mode(self, change):
        """ If the mode changes. Refresh the items.
        
        """
        block = self.block
        if block and self.is_initialized and change['type'] == 'update':
            if change['oldvalue'] == 'replace':
                raise NotImplementedError
            for c in self.children:
                block.children.remove(c)
                c.set_parent(None)
            self.refresh_items()
def _observe_mode(self, change):
        """ If the mode changes. Refresh the items.
        
        """
        block = self.block
        if block and self.is_initialized and change['type'] == 'update':
            if change['oldvalue'] == 'replace':
                raise NotImplementedError
            for c in self.children:
                block.children.remove(c)
                c.set_parent(None)
            self.refresh_items()
If the mode changes. Refresh the items.