1.5 Why use the LANSA Repository?

Using the LANSA Repository provides significant benefits to the development of all applications, but in particular to client/server applications, which are often created by a number of different developers or end user department personnel.

By using the LANSA Repository, you gain:

• Consistency throughout your organization. A field or file definition has the same description, validation and attributes, wherever it is used. This consistency is a recognized factor in reducing user training.

• Quality, because definitions, in general, are already in use and have been tested. Unit and system testing turnaround is reduced.

• Easier Maintenance as all fields and file related definitions are maintained in one place.

• Data Security as Repository validations and security levels are automatically enforced in client applications in the same way as they are for IBM i functions.

• Impact Analysis, which allows you to quickly and accurately determine the effects of changes to a field. For example, to determine which files and LANSA functions use a particular field.

The Repository information is not only available to an application, but in some cases it is actually enforced. Validation rules and security access, for instance, cannot be bypassed by an application. Whether the IBM i data is manipulated by a LANSA function or a client application via LANSA Open, the data must adhere to the validation rules and security requirements defined in the Repository.

If validation rules are not met, error messages defined in the Repository are sent to the client application through LANSA Open. If a validation rule, error message or help text is changed in the Repository, none of the client applications need to be changed or recompiled. New or changed rules and help text are picked up automatically.

Files defined in LANSA are standard IBM I files, accessible to non-LANSA applications. Only the extra LANSA Repository facilities, such as validations and virtual fields, help text, multilingual translation, and so on, are available to applications developed using LANSA, or client applications accessing the IBM i data via LANSA Open.

Conversely, files maintained by non-LANSA applications can be made known to the LANSA Repository. All LANSA's Repository facilities can be added to these files and used by the client application. This will not affect the original file at all.

Re-using Repository information by a number of applications creates a need for standards to be set and a commitment to be made to the use of these standards.

Some recommended standards are:

• Files and fields are defined in one, and only one place.

• All designers and application developers refer to this place for the definition.

• Reference fields to be used wherever practical for dates and other standard fields.

• All application developers use a "corporate" vision when updating the Repository. Every element in the Repository should be considered for corporate use, not just for one screen in one program or application.

• Security established to control not only what goes into the Repository, but also who can change it.

Guidelines for field and file standard names can be found in the LANSA Application Design Guide or the LANSA for i User Guide.