Among the many new features added in PowerBuilder 6, the Datawindow buttons are probably the ones least talked about. However, the Datawindow buttons coupled with the power and flexibility of the Datawindow form a potent combination which can introduce a whole new user interface paradigm.

Datawindow buttons are the latest addition to the objects that can be placed on a datawindow. To place a button on a datawindow, in the datawindow painter choose from the drop down toolbar. The properties of a datawindow button are similar to those of other datawindow objects including support for conditional attributes. Datawindow buttons can also display pictures.

PowerBuilder 6 provides two types of datawindow buttons-

1. Buttons with predefined actions like Insert, Delete, Save, Save As etc.
2. Buttons with user defined actions

The predefined buttons do make things extremely easy and simple, however I doubt if they will be used widely. This is because most PowerBuilder development today uses class libraries and frameworks like the PFC. Most of these frameworks incorporate 'hooks' in their code for developers to code validations and other application specific code. Ex. a reinsert event or a presave event. Such coding practices also enforce a standard style of coding. Since the predefined datawindow buttons will bypass the framework code, it is unlikely that a development team would want to use it at the cost of sacrificing the benefits of a framework.

Datawindow buttons with user defined action allow the developer to handle the action to be performed. For this the developer must code the 'buttonclicked' event of the datawindow. The arguments to the buttonclicked event provide the information about which button was clicked.

The user defined buttons present a lot of possibilities. Here are nine COOL ways to use the new datawindow buttons.....

Download: The prototype application. Click here.

1. Header Sorting
Clicking on the column sorts the datawindow by that column, similar to a listview.

2. Open File Dialog
Clicking on the button open the windows Open file dialog for selecting a file and associating it with the record.

3. Edit File
Clicking on the button opens the file in the associated application for editing.

4. Custom Selection List
Clicking on the button opens a response window from which the user can choose a record for the field.

5. More Info
Clicking on the button displays a drop down with more info about the current row.

6. Row operations
Buttons with options for operating on the current row. The buttons are visible only for the current row. This is achieved by using the conditional attributes.

7. Drop Down Menu
Clicking on the button displays a menu with more options.

8. Corner Menu
The button is placed in the top left hand corner. Clicking on the button displays a menu with options which can be applied to the entire datawindow.

9. Extended Entry
Clicking on the button open a response which allows the user to input additional optional data.

Download: The prototype application. Click here.

Jiggy, 07 June 1998