I am new in Acceleo. I use eclipse Mars. I want to getting start and learn with this link. when I want to create a new project and click add in the field of Metamodel URIs I didn't find UML Metamodel. what can I do?
The UML metamodel is only accessible by Acceleo if it is registered in the global EMF ERegistry. It means that it must be either loaded as an EMF plugin in your Eclipse environment or manually added to the global registry of your running Eclipse instance.
For UML, it is quite simple, you need to install the UML2 plugin. It provides the UML metamodel java code and .ecore as well as many tools around UML.
Also, if you want more details about Acceleo syntax, you can use these links:
http://help.eclipse.org/mars/topic/org.eclipse.acceleo.doc/pages/reference/language.html
https://wiki.eclipse.org/Acceleo/OCL_Operations_Reference https://wiki.eclipse.org/Acceleo/Acceleo_Operations_Reference
https://wiki.eclipse.org/Acceleo/Text_Production_Rules
And a small tutorial I wrote (only part 1 at the moment):
http://blog.genmymodel.com/build-your-own-php-generator-from-uml-using-acceleo-part-1.html