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If you want to develop modules that do not operate according to the generalized defaults, Oracle Developer/2000 provides a feature called user extensibility. This feature enables you to write procedural program code (using PL/SQL) to override the default operation of Oracle Forms applications. You can use these program units and triggers for data validation, secondary data retrieval, or transactional control, to name just a few of the uses of this feature.

In today's ever-changing environment of corporate and MIS right-sizing, Developer/2000 (like all prior Oracle front-end tools) features the capability to run on a vast array of computer platforms. Portability enables you to write and test applications on one platform and then "port" them to another system without any programming changes. Many organizations construct systems on stand-alone or networked PCs and then migrate them to an enterprise UNIX or mainframe computer. Except for minimal user interface changes, the entire migration should not require any code modifications, which enables MIS departments to free themselves from lifetime commitments to obsolescing computer environments.

Another feature of Developer/2000 is that all its components were designed to be integrated. A complete database system requires the capability to display and maintain data in an online environment accessed by many diverse users. Many times, users need reports that summarize information not available on-screen or need to provide a tremendous amount of detail that is not practical in an online mode. Additionally, users sometimes need hard-copy reports for external customers or vendors . Finally, graphical displays of data help users understand the information as it is presented. Through the use of menus , module tie-ins, and other functionality, Developer/2000 is a complete database management tool.

Finally, you can use the Developer/2000 tools with non-Oracle data sources. This feature is especially useful in an environment in which users can access data from a variety of sources. You can use the Developer/2000 tools to migrate data from a legacy database (for example, DB2) to the Oracle database. The Oracle tools can also access normal text files directly using some of the interface functions that are provided.

Common Tool Set Features

To provide a consistent development environment, several elements of the Developer/2000 tools are universal to all three tools. By learning how to use the function within one tool, you understand how to use it in the others.

The Object Navigator

The Object Navigator, shown in Figure 34.1, is used to present an interface to the hierarchical structure of all opened application units. The example shown is for a new Oracle Forms 4.5 module; however, all the Developer/2000 tools use a similar Object Navigator interface.

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Figure 34.1.
The Object Navigator.

Within the Object Navigator window, the structure of all open units is displayed in either the Ownership view (shown in the figure) or the Visual view. The Ownership view displays the object structured according to the block (representing records from a single table or view) where each is found. The Visual view, on the other hand, displays objects structured according to where they appear on the end-user screen. You can use the Navigator menu item to select the view that you want based on your own personal preference. Each item in the displayed structure can be preceded with an expand (+) or contract (-) icon to inform you that further details can be displayed for the object. By moving the mouse cursor and clicking a highlighted icon, you can expand the structure to show the next lower level of detail or remove the lower level from the display.

Standard scrollbars are provided on the right and bottom of the Navigator to enable you to change the portion of the application structure that appears within the window. Buttons that close, minimize, and maximize windows are also included; they operate similarly to those found in most Windows applications.

Below the Navigator window title bar are two fields and two icon buttons. The first field displays the currently selected item in a listbox. (Note that the currently selected item is also highlighted in the Navigator window, but because it can be "scrolled out" of the window, this field reinforces the selection.) The second field is the Find item. You can type in this box and press Enter to automatically navigate to the entered item. The two icon buttons (which look like flashlights) are used to search for the item in the Find box in either the forward or reverse direction.

The last part of the Navigator to be discussed is the icon button bar, which appears on the left side of the Navigator window. You use these buttons to perform tasks that can also usually be executed using menus or hotkeys.

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The first button appears as a partially open file folder and is used to open existing application units, which can be Forms modules, menus, or program unit libraries when used in Oracle Forms. The next button, which appears as a floppy disk, is used to save the current module to either a file or the database.

You use the next two buttons, a traffic light representing go, and an insect-like creature, to run the application module and to toggle the debugger facility on or off. If the debug facility is on, you can trace program execution and track changes to application variables when the application is run.

The next series of buttons represent cut, copy, paste, copy properties, and paste properties. The first three work in the same way as the corresponding Windows 3.1 functions, whereas the last two are used to copy the individual properties of one object to another existing object of the same type.

You use the next set of buttons to add and delete objects within the Navigator. Depending on the currently selected object in the Navigator, the newly added item is created using intelligent defaulting to rapidly create application functionality. Intelligent defaulting refers to the fact that based on the context of the activity, the default properties of the items reflect the type of item and the environment within which it is inserted.

You use the last set of icon buttons to expand and contract the structure of the module. These buttons, in order, are expand item, contract item, expand all lower items, and contract all lower items.

Database Connectivity

One of the features of the Developer/2000 tools is that you can use them without connecting to an Oracle database. This enables you to work on an application unit while you are unable to connect to an Oracle database. However, to generate (compile) an application unit or run the module, you must connect to the database using the dialog box shown in Figure 34.2.

Figure 34.2.
Connecting to an
Oracle database.

The first two fields in the Connect dialog box represent the user ID and password. (Note that the password appears as asterisks as it is typed.) The third field is the database connectivity string. For local database access, this field can be empty; however, for remote database access, this field is required. The definition for this field appears in the user's oracle.ini (for Windows 3.x) or corresponding file. The connectivity string should be provided by your system administrator, who will also set up your user ID and password.

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