ITEM_LINKED

The item_linked category defines parent-child relationships between data items. This provides the mechanism to specify the relationships between data items that may exist in multiple categories. Link relationships are most commonly defined between key items, which form the bases for many different categories.

In the DDL presented here, all child relationships are expressed within the parent category. Because the item, _item_linked.parent_name, has been defined as an implicit item, the child relationships can be specified most economically in the parent category where the parent item name can be automatically inferred. If link relationships are specified in a child category, then both parent and child item names must be specified.

Both parent and child item names in this category are children of _item.name which ensures that all link relationships can be properly resolved. However, it is possible to define cyclical link relationships within this category. Any implementation of this DDL category should include a method to check for the existence of such pathological cases.

The DDL for the item_linked category is given in the following section.

save_ITEM_LINKED

    _category.description
;
     Attributes which describe how equivalent data items are linked
     within categories and across different categories.
;
    _category.id                         item_linked
    _category.mandatory_code             no
     loop_
    _category_key.name                  '_item_linked.child_name'
                                        '_item_linked.parent_name'
     loop_
    _category_group.id                  'ddl_group'
                                        'item_group'
     save_


save__item_linked.child_name    

    _item_description.description
;
     Name of the child data item.
;
     save_


save__item_linked.parent_name   

    _item_description.description
;
     Name of the parent data item.
;
     save_