A link is used to define a navigation pathway between two GUI components. For example, defining a link between a "Customer List" and a "Customer Detail" GUI component will let users of your application navigate from the "Customer List" to the "Customer Detail".
A link provides a context to the GUI component it is linked to. For example, a "Purchase List" that has been linked to by a "Customer Detail" would list only those purchases for the customer in "Customer Detail".
A link can be internal or external. An internal link represents a navigation pathway between two GUI components on the same page. An external link represents a navigation pathway between two GUI components on different pages.
In some cases it does not make sense to have a link between two GUI components. This may be because the entities for the GUI components are unrelated, or the GUI components are for the same entity.
Following is a list of valid links:
| Lp -> Dp | |
| Lp -> Lc * | |
| Lp -> Dc | |
| Dp -> Lc * | |
| Dp -> Dc |
Where:
| L - is a list GUI component | |
| D - is a detail GUI component | |
| p - is a parent entity in an identifying relationship with child entity c | |
| c - is a child entity in an identifying relationship with parent entity p |
* Only when the relationship between p and c is one-to-many.