Compuware bets the farm on CBD

Software Magazine, Sept, 1998 by Dan Kara

In last month's column I argued that 4GLs and modeling tools capable of generating applications (generative modelers) provide the best support for what I termed component development with a big "C". That is, they are the best option for building medium- to large-scale business systems using component development technologies and techniques. At that time I argued that these classes of toolsets have historically offered strong support for cross-platform development, workgroup enablement, configuration and project management and model-based development, functionally required to build business systems of any size and scope.

One clear differentiator between 4GLs and generative modelers, and other types of component development tools, is that over the years, 4GL vendors have accumulated vast libraries of "canned" 4GL routines, which have subsequently been encapsulated as components and made available within the toolsets. These components differ from those that ship with other classes of component development tools, in terms of their number (there are more of them), their size and scope (they are large-grained and provide complex functionality), and their orientation (they are decidedly business-centric).

So far I have been speaking in terms of generalities, but what about specific examples of high-end 4GL and model-based component development environments? Compuware's Uniface development environment is a leading exemplar of how high-end component development can be supported by a 4GL-based generative modeler. The product also demonstrates how development tools can be reworked over time to support new developmental approaches while carrying forward and capitalizing on their core strengths.

History's Role

Uniface is a classic example of a "pure" 4GL. Pure 4GLs began their product lifecycles with the ascendance of relational database management systems (but before the advent of client/server computing), and were initially found on Unix and VMS platforms. Over the years and with each new release, Uniface supported an increasing number of development and deployment platforms and databases, and evolved to provide extensive direct functionality for creating large, complex, and scalable business systems.

As each new developmental paradigm emerged d client/ server, object orientation (OO) and the Internet come to mind-competitive 4GL-based products emerged (i.e. client/server 4GLs, OO 4GLs and Web 4GLs) that initially had a distinct competitive advantage over Uniface. In each case the advantage was short-lived. Uniface evolved to support client/server (what tool does not?), the best aspects of the object movement (stressing the pragmatic aspects of the OO movement in the form of component development), and Web enablement with its WebEnabler feature (again, what tool does not?). Uniface added support for each of these new approaches, but not at the expense of its hard-won ability to build complex business systems targeting many platforms and databases. Unfortunately, Uniface's competitors did not have this basic core functionality to build on and they have suffered from other problems. For example, dedicated Web 4GLs continue to have limited applicability, specialized OO 4GLs require extensive training and a conceptual leap of faith to adopt, and client/server 4GLs still do not scale.

Compuware's Uniface

High-end corporate development is not the sole purview of Uniface, and as noted earlier, all tools now support component development. So what makes Uniface special? First, Uniface is a model-based development environment, but the modeling does not come at the expense of RAD, in fact it supports it. In Uniface, application specifications are captured at a high level of abstraction in logical business models. The business models consist of interface requirements, data models, and business rules (held in an Application Model), business objects (collections of entities with some process logic), and process logic that act on the business objects. Actually, the specifics are not important. What is important is that applications are captured in high-level models that are stored in a repository along with other application objects.

Modeling implies high levels of system understanding, a key requirement for building substantive systems. Besides, any definition of components must not be limited to software modules and frameworks for combining components, but also modeling tools capable of generating the same. This is component development taken to a higher abstraction, and will increase developer productivity to a greater degree than can be attained by using low-level reusable objects. Reuse is not limited to software modules, but is extended to include reusable models, as well as the code those models generate. The model is the component. Uniface carries the concept of model-as-component even further, supporting the concept of inheritance for its models (changes made to a parent model are propagated forward to child models).

Uniface supports both de facto industry standard components, as well as its own proprietary componentry in the form of Uniface Building Blocks-- a collection of prebuilt and pretested Uniface components that market research and years of real-world experience have found to be commonly employed in many application types. For example, component template Building Blocks are skeleton forms, reports, and services (components designed to handle processing) with all definitions and properties predefined (and editable). Building Blocks for Application Models, error handling, caching, menuing and other functionality, along with a set of standards and guidelines that cover coding and naming conventions, also ship with the product. Compuware will add to the library of Building Blocks with each new release, and is actively working with its partners to build an arsenal of components and application templates using Building Blocks. Compuware has even developed a "Component Plaza" Web site for uploading, as well as finding, Uniface componentry.