In this chapter, we’ll see about the application & module structures.


An application is nothing but a configuration of a set of modules. The modules are built-time packages handled with Gradle build system.

Here is a directory structure of a typical axelor application:

Directory Structure
└── src
│   └── main
│       ├── java
│       └── resources
│           └── META-INF
│               ├── axelor-config.properties (1)
│               └── persistence.xml (2)
├── gradle (3)
│   └── wrapper
│       ├── gradle-wrapper.jar
│       └── gradle-wrapper.properties
├── modules (4)
├── gradlew (5)
├── gradlew.bat (5)
├── settings.gradle (6)
└── build.gradle (7)
1 The application config file
2 The minimal persistence xml file to confirm JPA requirement
3 The directory to keep gradle wrapper files
4 The directory to keep module projects
5 The shell and batch scripts to execute the build with wrapper
6 The gradle settings script
7 The gradle build script

The modules directory contains application specific feature modules. First, let’s see about some important files here before checking module structure.

The build.gradle file is a build script used by gradle to build the application.

plugins {
  id 'com.axelor.app' (1)

axelor { (2)
  title = 'Axelor DEMO'

allprojects {

  group = 'com.axelor'
  version = '1.0.0'

  java {
    toolchain {
      languageVersion = JavaLanguageVersion.of(11) (3)

  afterEvaluate {
    test {
      useJUnitPlatform() (4)
      beforeTest { descriptor ->
        logger.lifecycle('Running: ' + descriptor)

dependencies {
  // add dependencies
  implementation project(':axelor-contact') (5)
1 Use axelor application plugin
2 The application project config
3 Use Java 11
4 Use JUnit5 for unit testing
5 Add dependencies

The com.axelor.app gradle plugin defines an extension point axelor where we can define various properties.

  • title - display title for the application

  • description - a short description of the application

Another important build script is the settings.gradle where we configure the gradle build and aggregates all the feature module projects to be used in current build process:

pluginManagement {
  repositories {
    maven {
      url 'https://repository.axelor.com/nexus/repository/maven-public/' (1)
  plugins {
    id 'com.axelor.app' version '6.0.+' (2)

dependencyResolutionManagement {
  repositories {
    mavenCentral() {
      content {
        excludeGroup 'com.axelor' (3)
    maven {
      url 'https://repository.axelor.com/nexus/repository/maven-public/'
    ivy { (4)
      name = "Node.js"
      patternLayout {
      metadataSources {
      content {
        includeModule("org.nodejs", "node")

rootProject.name = 'axelor-demo'

// Include modules
include 'modules:axelor-contact'
1 The axelor maven repository
2 The axelor app gradle plugin version
3 Use maven central but don’t load com.axelor from it
4 The Node.js repository

The include 'modules:axelor-contact' line tells gradle to include the module axelor-contact in current build cycle. It is required to list all the modules used by the application in settings.gradle file.

AOP dependencies resolution

By default, Gradle resolves dependency version conflicts by using the newest version of the library. This is generally ok, but sometimes, depending on the modules used and on AOP versions used when they have been published, it may use an unwanted version.

In order to avoid using an AOP version coming from transitive dependencies (selected by Gradle) and thus using the AOP version defined in the project itself, apply the DependenciesSupport plugin on the root project:

apply plugin: com.axelor.gradle.support.DependenciesSupport

Changelog plugin

AOP provides a Gradle plugin to simplify changelog management.

Each entry of the CHANGELOG.md file is generated from files in the changelogs/unreleased/ folder.

The file is expected to be a YAML file in the following format:

title: Some text
type: feature
description: |
  some description here
  with more details.

  And some details about breaking changes
  and migrations steps.

  UPDATE some_table SET foo = 'bar';


  • title: describe the entry. (Mandatory)

  • type: type of the entry (feature, fix, …​). (Mandatory)

  • description: provide detail description about the changes including migration steps if any. (Optional)

The plugin will parse all entries in the changelogs/unreleased/ folder to generate the changelog of the version in CHANGELOG.md. The unreleased entries are also automatically removed.

To use the plugin, in your build.gradle:

apply plugin: com.axelor.gradle.support.ChangelogSupport

changelog {
  version = "${project.version}"
  types.set(["Feature", "Change", "Deprecate", "Remove", "Fix", "Security"])
  header.set("${version.get()} (${new Date().format("yyyy-MM-dd")})")

Plugin can be configured with the following properties set in the changelog extension:

Property Description Default


Current version

current project version


Path to the changelog file



Path of the unreleased entries



List of types

["Feature", "Change", "Deprecate", "Remove", "Fix", "Security"]


Header value when generating changelog for the current version

"${version.get()} (${new Date().format("yyyy-MM-dd")})"

To generate the CHANGELOG.md with unreleased entries, run the following Gradle task:

./gradlew generateChangelog
--preview argument can also be used to preview the generated changelog without deleting/updating files.


The application project generally doesn’t provide any implementation logic. The functionalities should be provided by creating modules.

A module is again a gradle sub project. Usually created inside modules directory. However, you can use any directory structure. See gradle multi-project builds documentation for more details.

Now let’s see what a feature module directory structure looks like:

Directory Structure
├── build.gradle (1)
└── src
    ├── main (2)
    │   ├── java
    │   └── resources
    │       ├── domains (3)
    │       ├── views (4)
    │       └── i18n (5)
    └── test (6)
        ├── java
        └── resources
1 The gradle build script
2 The main sources
3 The XML resources for domain object definitions
4 The XML resources for object view definitions
5 The CSV files with translations
6 The unit test sources

You can see the module structure follows standard maven/gradle directory structure.

Let’s see the build.gradle script for the module.

plugins {
  id 'com.axelor.app' (1)

axelor { (2)
  title = "Axelor :: Contact"
1 The gradle plugin for module project
2 The module project configuration

The com.axelor.app plugin defines an extension point axelor where we define various properties.

  • title - display title for the module

  • description - a short description about the module