Project Notes

Project: Share Navigator and StatusBar Between DataSets

Description:
This sample application contains the completed files from the tutorial entitled "Displaying or hiding navigator buttons at run time" in the Database Application Developer's Guide. It shows how two datasets displayed in grids can share a single NavigatorControl and StatusBar. The two datasets used here are the DEPARTMENT and EMPLOYEE tables from the InterBase sample database, joined in a maser-detail relationship. For the purposes of the example we assume that users are not allowed to modify the DEPARTMENT table, and demonstrate how the buttons on the navigator control that allow editing can be diabled when the grid displaying the DEPARTMENT table receives focus, then enabled again when the grid displaying the EMPLOYEE table receives focus.

Before you run this application, install and set up Local InterBase Server and the sample data source as described in "Installing and setting up Local InterBase Server" in the Database Application Developer's Guide. This tutorial also requires that you have a version of JBuilder that includes the JBuilder DataBroker database architecture components.

Note: All versions of JBuilder provide direct access to SQL data through the JavaSoft JDBC API. Some versions of JBuilder provide additional DataBroker components (on the Data Access tab of the Component Palette) that greatly simplify RAD visual development of database applications. Refer to the JBuilder product page from the Borland Web site at http://www.borland.com for availability of features in each JBuilder version.

Running the Application:

Use the keyboard, mouse, or navigator to scroll through department data in the upper grid. Note that the buttons on the NavigatorControl to modify data (insert or delete row, save or cancel changes, and so on) are not available and that the StatusBar updates as you navigate.

Tab to the lower grid displaying the EMPLOYEE dataset. Now all the NavigatorControl buttons are available and the messages on the StatusBar reflect your position in the detail grid.

We've established a master-detail relationship between the two datasets, so for each department you see data on the employees who work in that department.

You can insert, delete or modify the employee data. If you click the Save button of the NavigatorControl, your changes will be resolved back to the server table. In this simple example you can also edit department data, but there's no way to save those changes permanently. In a complete application, we would set the DEPARTMENT table's readOnly property to true to prevent editing.

Note: Because of data constraints on the EMPLOYEE table, the save operation may not succeed depending on the data you change. Since other edits may return errors, we suggest you make changes only to the FIRST_NAME and LAST_NAME values in existing rows until you become more familiar with the constraints on this table. For more information, see the "Tips on using InterBase" topic in the Database Application Developer's Guide.