Introduction

From there to here,
from here to there
funny things are everywhere.
(Dr. Seuss)

The CCM Tools are a set of Java programs and libraries as well as Python scripts that supports the development of components, based on the CORBA Component Model (CCM) [10]. As shown in Fig. 1.1, the CCM Tools form a component development framework that is flexible and extensible.

Using a well defined CCM model, we can separate the component description from the code generator tools. Therefore, we can add new description methods (e.g. UML) or code generator tools (e.g. Java Component Generator) without changing the other tools.

Figure 1.1: CCM Tools overview

Using a well defined CCM model, we can separate the component description from the code generator tools. Therefore, we can add new description methods (e.g. UML) or code generator tools (e.g. a Java Component Generator) without changing the other tools.

Note that the dashed tools are still under construction and therefore not part of the current release series (CCM Tools release series 0.3.x).

The CCM Tools framework contains the following tools:

CCM Metamodel Library

The CCM specification defines an Interface Repository Metamodel for the IDL3 syntax. We implemented a CCM Metamodel Library that allows creation and iteration of CCM models. Using this library we can clearly separate the parser and the code generators. The parser creates a model object for every part of the source code matching an IDL grammar rule.

IDL3 Parser

The IDL3 Parser reads the IDL3 file, checks the syntax of the IDL source code and creates a CCM model using the CCM Metamodel Library in the memory. This CCM model is the starting point for all code generator tools in the framework.

IDL3 Generator

To test the functionality of the CCM Metamodel Library and the IDL3 Parser we implemented an IDL3 Generator that writes out the CCM model in a corresponding IDL3 File.

IDL3 Mirror Generator

We use a Test-Driven Development (TDD) strategy to develop and to specify components (as described later in this tutorial). Our component unit test uses a mirror component to connect all ports of an existing component. The IDL3 Mirror Generator creates the IDL3 syntax definition of this mirror component.

Local C++ Component Generator

The component model is realized by the component logic that implements the operations for providing, using and connecting components by their facets and receptacles. We implemented a generator tool that creates the local component logic from a given CCM model. After generating the component logic, the component developer only has to write the business logic within the generated component skeleton.

Local C++ Mirror Generator

After building a local C++ component we have to run a functional test on it. To provide a suitable test environment we create a mirror component as well as a test client that manages the component unit test.

Local Python Component Wrapper Generator (under construction)

For rapid prototyping and the development of glue components we use heterogeneous local C++/Python components. The component logic, including the component's interfaces, are implemented in C++ while the business code can be hacked in Python - without need to compile and redeploy after changes.

IDL2 Generator

To implement CORBA components the IDL3 source code is mapped to IDL2 that can be processed by a classic IDL2 Compiler (currently we use the Mico ORB). The transformation from IDL3 to IDL2 also adds some operations needed for navigation between components and their ports (equivalent operations). We support this transformation by a IDL2 Generator tool that creates IDL2 from an existing CCM model.

Remote C++ Component Generator (under construction)

The local components can only be used in a common address space and must be implemented in the same programming language. To overcome these limitations we generate remote component logic that interfaces the local components with CORBA. The remote component logic is thus a superset of the local component logic. Note that the external view of such a remote component quite conforms to the CCM specification.

Component Descriptor Generator (under construction)

To describe the component for the deployment and the assembling process the OMG defined a CORBA Component Descriptor (CCD) file. This is an XML file containing a short description of a component and its ports. We use the CCM model and information from a user interface to generate the specified descriptor file.