Menu form field type
From Joomla! Documentation
The menu form field type provides a drop down list of the available menus from your Joomla! site. If the field has a saved value this is selected when the page is first loaded. If not, the default value (if any) is selected.
The first option on the list is always '- Select Menu -' (which is a translatable string) and is given the value 0.
- type (mandatory) must be menu.
- name (mandatory) is the unique name of the field.
- label (mandatory) (translatable) is the descriptive title of the field.
- default (optional) is the default menu. Note that this is the name of the menu shown in the Type column on the Menu Manager screen and not the menu ID number.
- description (optional) (translatable) is text that will be shown as a tooltip when the user moves the mouse over the drop-down box.
Example XML field definition:
<field name="mymenu" type="menu" default="mainmenu" label="Select a menu" description="Select a menu" />