Application Planning with the Application Framework

Articolo
10/23/2006

After you run the Application Wizard you will have an open project containing a number of files that comprise the application framework. The framework manages the following tasks for you:

Provides startup and cleanup routines including saving and restoring of the environment state.
Displays menus and toolbars.
Manages integration of your user-defined forms and reports.

The framework helps you answer questions about what your application does, how users input data, what kind of application the user sees, and how to add the greatest functionality.

Step 1: What do you want your application to do?

Because data is a critical part of your application and can impact performance, it's important to know about proper database design and optimizing techniques. Your datasources can be Visual FoxPro tables, or remote views to back-end hosts such as SQL Server. Also, you should consider issues presented by any multi-user requirements of your application

The Application Builder allows you to use your existing data, or generate a new database with template tables for your specific application needs. The Adding Data topic describes how to integrate data in your application.

Step 2: How will users input data?

Data input is the first activity performed with a database application, and you should decide how you want users to enter data. Typically, a data-input form is used for entering data. Because of potential conflicts when multiple users edit the same data, the most common continuing activity of your forms in multi-user environments is properly handling conflict resolution.

You should choose the type of form that is appropriate for your application based on the structures of your data. You might have a simple datasource where a single table form is sufficient. Other situations may dictate using a more complex 1-to-Many form.

The Application Builder provides program code to add existing or new forms for the application framework. The Builder also lets you control how these forms integrate with the application.

Step 3: How will data be reported?

In addition to input, your application must support display of data, often achieved through reports. Applications tend to be in one of two styles, input intensive or output intensive. Output-intensive applications often contain many reports and facilities for analyzing and manipulating data.

Step 4: What type of application do you want?

After you deal with the data specifics, you can choose a style for your application. The style or type you select depends on the context of your application. Your application can run as the sole application in the Visual FoxPro window, as part of another application, or as a top-level application without the Visual FoxPro desktop.

Use options in the General tab of the Application Builder to specify whether your application is to be a Normal, Module, or Top-level application.

Normal –the application runs entirely in the Visual FoxPro desktop.
Module – the application runs as an add-on to an existing application.
Top-Level – the application runs in the Windows environment.

Step 5: What common features do you want for your application?

Most Windows applications have several standard features, such as a Splash screen, About dialog box, a standard toolbar, and a Help file. In addition, some applications have a Quick Start dialog box, User Login dialog box, and a Favorites menu.

The application framework supports these common application features and assists you in choosing which features you want. The General tab of the Application Builder lets you provide information such as credits and version information, which is used by some of these options.

Step 6: How can you add more powerful features to the application?

By using exclusive features of the Application Builder, you can create a fully functional and useful application. The Application Builder leverages the power of several wizards including the Form Wizard, Report Wizard, Database Wizard, and Table Wizard to simplify this process without any additional coding required.

You might want to extend functionality beyond the applications you can create with the Application Builder by using the Component Gallery and Foundation Classes. Visual FoxPro ships with over 100 foundation classes you can use to easily add effective enhancements to your application. These include data lookup and query-by-form controls, web hyperlinks, navigation toolbars, special effects, and offline data handlers. The Component Gallery also contains other useful components such as ActiveX controls and COM components for use with your application.

Step 7: How do you build and package the application?

When you are ready to build and package your application, the Application Builder enables you to build, test, and modify the application at any time. Since the Application Builder is reentrant, you can easily update the original design and incorporate requests for added functionality.

The Project Manager handles all necessary files during the build process. You can choose to either build an .exe or .app file. Usually, you will select the EXE option when you are ready to distribute to users because it uses the Visual FoxPro runtime files.

The last step is to create a distributable application package. To do this, create a new folder and place in it your .exe file, data files, and any other files not compiled into the .exe.

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