See also Patterns Work With for a newer version of this page.
It's one of the most useful patterns in business applications. IBM was the first one to popularized it when they used it extensively in the OS/400 UI (see IBM CUA )
Since then, it was rapidly adopted by Genexus developers, and it's very common to see different implementatios of this pattern in winform or webforms applications.
It's a User Interface pattern, based on what its called Object Action dialogs: the user first select an object (to 'work with') from a list of them, and later applies an action to it.
Abstract Description
In its abstract form the pattern use the following components:
Selection List
It's a grid with the list of all objects. Usually this grid must have the following functionability:
- Paging
- Filtering
- Order
- Refresh
Actions
There are basically two kind of actions:
- Object specific. This actions applies to given object. Example: Update, Delete, View.
- Object independent. This actions don't apply to any particular object. Example: Insert.
Another way to classify the actions is in:
- Generic actions. Like Insert, Update or Delete.
- Particular actions. Like 'View Invoices of this Customer'. Something interesting of this actions it's most of them are 'navigational' (in the sense it's a drill-down on the data) so it can be infered by GX.
Data Entry
This is the component used for data entry purpose of an object. It's usually a GenexusTransaction .
Given this is a UI pattern, it is natural to have different variants of the pattern depending on the UI platform.
See Web Based Implementation of Work With Pattern