def item():

    # Filter to just Vehicles
    table = s3db.supply_item
    ctable = s3db.supply_item_category
    s3.filter = (table.item_category_id == ctable.id) & \
                (ctable.is_vehicle == True)

    # Limit the Categories to just those with vehicles in
    # - make category mandatory so that filter works
    field = s3db.supply_item.item_category_id
    field.requires = IS_ONE_OF(db,
                               "supply_item_category.id",
                               s3db.supply_item_category_represent,
                               sort=True,
                               filterby = "is_vehicle",
                               filter_opts = [True]
                               )

    field.label = T("Vehicle Categories")
    field.comment = S3PopupLink(f="item_category",
                                label=T("Add Vehicle Category"),
                                info=T("Add a new vehicle category"),
                                title=T("Vehicle Category"),
                                tooltip=T("Only Categories of type 'Vehicle' will be seen in the dropdown."))

    # CRUD strings
    s3.crud_strings["supply_item"] = Storage(
        label_create = T("Add New Vehicle Type"),
        title_display = T("Vehicle Type Details"),
        title_list = T("Vehicle Types"),
        title_update = T("Edit Vehicle Type"),
        label_list_button = T("List Vehicle Types"),
        label_delete_button = T("Delete Vehicle Type"),
        msg_record_created = T("Vehicle Type added"),
        msg_record_modified = T("Vehicle Type updated"),
        msg_record_deleted = T("Vehicle Type deleted"),
        msg_list_empty = T("No Vehicle Types currently registered"),
        msg_match = T("Matching Vehicle Types"),
        msg_no_match = T("No Matching Vehicle Types")
        )

    # Defined in the Model for use from Multiple Controllers for unified menus
    return s3db.supply_item_controller()

# =============================================================================
RESTful CRUD controller
dataset/ETHPy150Open sahana/eden/controllers/vehicle.py/item