Expansion Steps

AdditionalExpansionSteps are a way to add logic before or after expanding.

Some of the AdditionalExpansionSteps provided by the ExpandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. you may already know:

• ExtDirectoryCopierStep: copies the ext directories for each Component to the expansion folder from the source directory
• ExtDirectoryHarvesterStep: harvests the customizations in the ext directories
• OverlayDirectoryCopierStep: copies overlay files after expansion

Setup

AdditionalExpansionSteps have 2 components:

• An XML file describing the step
• A java implementation implementing the AdditionalExpansionStepImplementation interface

MyExpansionStep.xml

<additionalExpansionStep name="MyExpansionStep" xmlns="https://schemas.normalizedsystems.org/xsd/prime-core/2022/10/1/additionalExpansionStep">
  <packageName>net.democritus.some.package</packageName>
  <!-- Can be Application, Component or even Elements, like DataElement -->
  <elementTypeName>Application</elementTypeName>
  <!-- Always java, no alternatives yet -->
  <type>java</type>
  <!-- phase of the expansion when to run the step -->
  <phase>expansion</phase>
  <!-- If defined, this expansionStep will only run when the technology is present -->
  <technology name="EJB3"/>
  <!-- condition when to run the step -->
  <isApplicable>true</isApplicable>
  <!-- set to false to exclude this step -->
  <active value="true"/>
</additionalExpansionStep>

MyExpansionStep.java

package net.democritus.some.package;

import net.democritus.elements.ApplicationComposite;
import net.democritus.expander.AdditionalExpansionStepImplementation;
import net.democritus.expander.context.ProgramExpansionContext;

public class MyExpansionStep
    implements AdditionalExpansionStepImplementation<ProgramExpansionContext<ApplicationComposite>> {

  public void run(ProgramExpansionContext<ApplicationComposite> expansionContext) {
    // Implement some logic
  }

}

---

packaging

AdditionalExpansionSteps are packaged just like ExpandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact. and Features by the expansionResource mojo of the expandersExpanderA unit of generation that combines a data tree instance (functional M1 model) with a template to generate an artifact.-maven-plugin. Just make sure you have an XML with the additionalExpansionStep tag and the name of the expansionStep ends with Step.

Copy files from Classpath to Expansion

During the expansion process, it's a common requirement to include static assets or configuration files from your expansion-resource into the generated output (the expansion directory). This can be achieved using an ExpansionStep, leveraging Java's ClassLoader to access files packaged with your expansion-resource.

Context: When and Why You Need This

Your plugin might need to copy files for various reasons:

• Static Assets: HTML templates, CSS files, JavaScript files for a web applicationApplicationThe overarching model container grouping all components, domain logic, and configurations for an enterprise solution..
• Configuration Files: Default configuration for generated code or external tools.

An ExpansionStep is the ideal place for this logic, as it operates within the controlled environment of the expansion process.

A detailed guide on how to create this ExpansionStep can be found in the Developer Hub: How to Copy files from Classpath to Expansion