Introduction to EGL development concepts

With EGL, you can use high-level constructs to create code that will run on one of several target platforms.
EGL generation and deployment
The EGL development process includes the following steps:
  1. At development time, you write code in the EGL editor. Your code periodically becomes an input to an internal process that validates your work. This validation focuses on general syntax errors. If your code fails validation, error marks are displayed in the editor.
  2. When you save source code that has no syntax errors, the validated code is written to intermediate representation (IR) files, which represent the compiled form of the EGL source. EGL build is the process of validating and compiling EGL source and then writing the compiled output to IR files.
  3. In IBM® Rational® EGL Community Edition, the IR files are an input to EGL generation, which is the following internal process:
    • Validation of your work for its conformance to a particular target runtime; for example, for use in a browser.
    • Generation of source code as JavaScript™, to use in a browser, or as Java™, to use as a Web service implementation. With the commercial EGL products, you can also create COBOL output.
    When you save code, EGL generation occurs automatically. You control the process by specifying the following files:
    • A build file (.eglbld), which includes details about what is being generated. The most important element in the build file is the EGL build descriptor. When you first use EGL, you might accept the default values that are specified for the build descriptor; as you become familiar with EGL, you might work in the Build Descriptor editor to customize that element.
    • An EGL deployment descriptor (file extension .egldd), which is used to control aspects of service access and service deployment.

    Rational EGL Community Edition includes two forms of the generated output: one for use by the EGL debugger, and a second, which lacks debugging detail, for deployment to a target platform.

  4. With a few keystrokes, you can invoke EGL deployment, which readies the code for deployment.
When you work with EGL, you specify some details for use at run time and some details for use by the EGL system code:

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