Acceleo/User Guide

Installing Acceleo

Acceleo can be downloaded and installed in a number of ways. If you have an existing Eclipse installation and simply wish to install Acceleo in it, Installing through the update site is the easiest way. If you'd rather install a new Eclipse with Acceleo, you may want to take a look at the facilities provided by the amalgamation project.

For those of you that need to retrieve the zips of Acceleo, you can either look at the latest releases or the legacy releases if you need one of the 2.x releases.

Note: Whatever the installation procedure you choose, examples are available from the menu right-click => New => Examples => Acceleo Plug-ins.

The Acceleo language

Acceleo 3 is an implementation of the MOFM2T specification defined by the OMG. The Acceleo language, named as MTL by the OMG, is composed of two main types of structures (templates and queries) inside of a module. In Acceleo, you can create expressions using a subset of OCL in order query the input models.

Modules

An Acceleo module is a ".mtl" file, which contains templates (to generate code) and/or queries (to extract information from the manipulated models). The file must start with the module declaration in the form:

[module <module_name>('metamodel_URI_1', 'metamodel_URI_2')]

A module can extend another module, in which case its templates will be able to override its parent's "public" and "protected" templates. It will also have access to its parent's public and protected templates and queries. A module can also import another module to access its public templates and queries.

Import

An Acceleo module generally depends on other modules for its execution. Consequently, Acceleo modules explicitly declare the modules they depend on via import declarations.

The syntax is the following:

import qualified::name::of::imported::module

The content assistant (Ctrl + Space) will propose you all accessible modules. Select the module you want to import and its qualified name will be inserted.

Note: It is possible to use a non-qualified name in an import, but this is not recommended since it can easily lead to bugs that are hard to understand in case of name conflicts between Acceleo modules.

The content assistant can be invoked to generate an import tag: just enter import, then Ctrl + Space, and the completion proposes "import" and generates an [import... /] tag.

Static Overriding

Acceleo allows you to override a part of the behavior of another module by extending it and by overriding some of its templates (all templates except those without with a private visibility). It can be very useful to re-use some common part of a module and to create common parents to several modules just like in object oriented programming.