View source for Xtext/Documentation/Migration

This document describes how Xtext projects of oAW 4.3 can be migrated to TMF Xtext. It assumes that you do have a running version of TMF Xtext as described in the [[Xtext/GettingStarted|Getting Started Document]].

'''work in progress'''

= Procedure =
== Setup new workspace with existing oAW Xtext projects ==
 * Might have compile errors, these projects are just for reference
 * Should contain generated code

== create new TMF Xtext project ==
Create your new Xtext project in this workspace with the Xtext project wizard. During this process you have to provide a fully qualified language name. Choose this name carefully, it not only affects the name of the language itself (last token). The package names of your projects are directly derived from this, too. To reduce the amount of migration work you should try to choose a name, that results in the same package structure and language name you had on oAW. Doing so, Xpand templates and Xtend files must not change their import statements. Leave the sample grammar unchanged and generate the Xtext artefacts as described in the GettingStarted document.

Start over if the resultung package or grammar names are not as expected. You can simply delete the created projects (be sure to tick "Delete project contents on disk").

== setup minimalistic model ==
Test, whether your generator project works. In the generator project you will find a workflow file in the package workflow. If everything works fine you are now having an empty set of Xtext projects that have package structure and language name in common with your oAW projects.

If not done, yet, put your newly created projects under version control. Having solid checkpoints during your migration can save hours of work.

Extract a simple model file from your original and place it into the model package of your generator project and run the generator again. You should now get some parser errors. This is fine since the default example grammar does not correspond to the syntax of your model file.

== migrate grammar and linking ==

URI -> Feature ImportURI

Int Rule has no sign, if necessary Parser Rules are a good choice

Enums not yet
Lexer Rules -> Terminal or DataType ParseRules

Also: See Jan's comment regarding linking https://bugs.eclipse.org/bugs/show_bug.cgi?id=268506#c1

== migrate workflow ==
<source lang="xml">
<component class="org.eclipse.xtext.MweReader" uri="classpath:/model/MyModel.mydsl">
    <!-- this class will be generated by the xtext generator -->
    <register class="org.xtext.example.MyDslStandaloneSetup"/>
</component>
</source>

Migrate Components
oaw.workflow.common.DirectoryCleaner -> org.eclipse.emf.mwe.utils.DirectoryCleaner
"directories" (deprecated) -> "directory"

<source lang="xml">
<component class='org.eclipse.emf.mwe.utils.DirectoryCleaner' directory='${targetDir}'/>
</source>

oaw.xpand2.Generator -> org.eclipse.xpand2.Generator

<source lang="xml">
<component class="org.eclipse.xpand2.Generator">
    <expand value="ise::intmsglang::doc::Main::main FOR mymodel"/>
    <metaModel class='org.eclipse.xtend.typesystem.emf.EmfRegistryMetaModel'/>
    <outlet overwrite="true" path="${targetDir}" />
</component>
</source>

oaw.xtend.XtendComponent -> org.eclipse.xtend.XtendComponent
oaw.check.CheckComponent -> org.eclipse.xtend.check.CheckComponent
 
Postprocessor
org.openarchitectureware.xpand2.output.XmlBeautifier -> org.eclipse.xpand2.output.XmlBeautifier
 
org.openarchitectureware.xpand2.output.JavaBeautifier -> org.eclipse.xpand2.output.JavaBeautifier


== migrate checks and templates ==

Qualified name of stdlib has changed from org.openarchitectureware.util to org.eclipse.xtend.util
<source lang="text">
extension org::openarchitectureware::util::stdlib::io -> extension org::eclipse::xtend::util::stdlib::io
«EXTENSION org::eclipse::xtend::util::stdlib::io»
</source>

== migrate headless build ==

Workflow Runner / Ant Tasks
Needed Jars

== migrate IDE ==

TBD

= Unexpected errors =
== ClassCaseException while Parsing ==

EvaluationException : org.eclipse.xtext.parser.ParseException: java.lang.ClassCastException: java.lang.String 

-> Missing ValueConverter

== DiagnosticErrors while compiling grammar ==
Errors such as

 XtextLinkingDiagnostic: null:21 Cannot resolve reference to 'ID'
 XtextLinkingDiagnostic: null:25 Cannot resolve reference to 'INT'
 XtextLinkingDiagnostic: null:238 Cannot resolve reference to 'STRING'

--> Missing super grammar 

== Cannot resolve reference to 'URI' ==
Import mechanism has been superseded