Steps to Developing SAS/AF Applications

You might consider setting up a common SAS library and appropriate catalogs for an applications development project. Often, this makes it easier for your development team to locate, share, and store the SAS catalog entries that your application requires.

You can store a mixture of entry types in a SAS catalog. The following table lists the common entry types that you are likely to use in your SAS/AF applications.

You can also use library or catalog concatenation so that you can access entries in multiple libraries or catalogs by specifying a single library reference name (libref) or a catalog reference name (catref). If you create a catalog concatenation, you can specify the catref in any context that accepts a simple, nonconcatenated catref.

For example, you might need to access entries in several SAS catalogs that might be designated as the development, test, and production areas. The most efficient way to access the information is to logically concatenate the catalogs, which allows access to the information without creating a new catalog. The following statement assigns the catref app to development, test, and production catalogs:

catname app (corp.app mis.testapp projects.newapp);

In this example, corp.app is the production environment, mis.testapp is the testing catalog, and projects.newapp is the development area.

Catalog concatenation is useful when you need to migrate catalog entries — particularly those that have hardcoded SCL entry names such as classes — between different environments. For details on catalog concatenation, see the SAS Language Reference: Concepts. For information about the use of libraries and catalogs when you deploy applications, see Step 6: Deploy Your Application.

Your organization might already have a number of existing custom SAS components available. If you plan to use any of these custom components in your new application, then you should consider how the classes are grouped and made available in a resource. For more information, see Deploying Components.

When you create an application, you can use the functionality of different SAS software products, or you can develop objects (such as a graph) that require other SAS software products to operate. In either case, you must ensure that your end users license all the SAS software products that they need for your application to run.

This phase of the development life cycle is where application developers build the system or application, using the objects that have been created by component developers. For complete information about using SAS/AF software to develop applications, see Part 2: Developing Applications.

You can use any one of a number of modeling tools and flow chart techniques to help determine how many windows your application will need, as well as how the user should interact with each window and how the windows should be connected to each other.

Consider the tasks that a user needs to perform in a window, and a frame that enables the user to complete those tasks. For information about building frames, see Working with Frames.

Your application design might specify that the components on a frame, or even the frames themselves, need to work with each other. For example, you might want a graphic object to display a specific graph when a user selects a graph from a list box. Or, you might want the user to open another frame when a push button is selected. You can add component and frame communication either by using SAS Component Language (SCL) programs or by taking advantage of the features included in components that have been built using the SAS Component Object Model (SCOM) architecture.

For more information about SCL, see Adding SAS Component Language Programs to Frames. For more information about SCOM, see Communicating with Components.

If you notice that several of your frames share common traits, you can create a composite object that includes those traits. For example, you could create a dialog box frame that included OK, Cancel, and Help buttons. For more information about composites, see Re-using Components.

When you use SCL programs with the frames of your application, you must compile and test your frames. You can perform debugging and unit testing as well. Once all of the individual pieces are working, you might also consider assembling all application components and performing integrated testing.

For information about compiling and testing, see Compiling and Testing Applications.

Although your application enables users to perform all the tasks that they need to complete, it might still be difficult to learn or to use. Just as the early analysis phase encourages input from users, you might want to revisit the design by having users test the application during its development. Usability testing enables you to enhance or correct usability issues that might arise from difficult concepts or business processes. There are many different types of usability testing, ranging from user exploration of the application to formal testing that assesses validity and usability.