Xtext Grammar mixins result in Guice injection error - parsing

Question

I am writing an Xtext grammar that can access documentation that are declared before a functions.
Our current grammar defines hidden(ML_COMMENT, SL_COMMENT,...) with:
ML_COMMENT: '/*' -> '*/'
SL_COMMENT: '//' -> EOL
I have now created a second Xtext project, with the following grammar:
grammar my.DocumentationGrammar with my.OriginalGrammar hidden(WS, FUNCTION_BODY, EOL, SL_COMMENT)
import "http://www.originalGrammar.my"
generate documentationGrammar "http://www.documentationGrammar.my"
/* Parser rules */
TranslationUnit:
eds+=DoxExternalDefinition*
;
DoxExternalDefinition:
def = Definition
| lib = CtrlLibUsage
| comment=ML_COMMENT
;
FunctionDefinition:
aml=AccessModifiersList ts=TypeSpecifier? f=Function '(' pl=ParameterTypeList? ')' /* cs=CompoundStatement */ // the compound statement is ignored
;
//terminal DOXYGEN_COMMENT: ML_COMMENT;
terminal FUNCTION_BODY: '{' -> '}';
I have created the dependency in the plugin and added this to the
bean = StandaloneSetup {
scanClassPath = true
platformUri = "${runtimeProject}/.."
// The following two lines can be removed, if Xbase is not used.
registerGeneratedEPackage = "org.eclipse.xtext.xbase.XbasePackage"
registerGenModelFile = "platform:/resource/org.eclipse.xtext.xbase/model/Xbase.genmodel"
// we need to register the super genmodel
registerGeneratedEPackage = "my.OriginalGrammar.OriginalGrammarPackage"
registerGenModelFile = "platform:/resource/my.OriginalGrammar/model/generated/OriginalGrammar.genmodel"
}
Now in my third plugin project, I want to access this parser in a Standalone fashion. So I created the following Parser file (based on this example: http://davehofmann.de/blog/?p=101) :
import java.io.IOException;
import java.io.Reader;
import java.nio.file.Path;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.xtext.parser.IParseResult;
import org.eclipse.xtext.parser.IParser;
import org.eclipse.xtext.parser.ParseException;
import org.eclipse.xtext.resource.XtextResource;
import org.eclipse.xtext.resource.XtextResourceSet;
import my.DocumentationGrammar.DocumentationGrammarStandaloneSetup;
import com.google.inject.Inject;
import com.google.inject.Injector;
public class DoxygenParser {
#Inject
private IParser parser;
private Injector injector;
public DoxygenParser() {
setupParser();
}
private void setupParser() {
injector = new DocumentationGrammarStandaloneSetup().createInjectorAndDoEMFRegistration();
injector.injectMembers(this);
}
/**
* Parses data provided by an input reader using Xtext and returns the root node of the resulting object tree.
* #param reader Input reader
* #return root object node
* #throws IOException when errors occur during the parsing process
*/
public EObject parse(Reader reader) throws IOException
{
IParseResult result = parser.parse(reader);
if(result.hasSyntaxErrors())
{
throw new ParseException("Provided input contains syntax errors.");
}
return result.getRootASTElement();
}
}
However, when I try to run it, I receive Guice Injection errors saying that
com.google.inject.ProvisionException: Guice provision errors:
1) Error injecting constructor, org.eclipse.emf.common.util.WrappedException: java.lang.RuntimeException: Cannot create a resource for 'classpath:/my/documentationGrammar/DocumentationGrammar.xtextbin'; a registered resource factory is needed
I know that the parser "should" be correct, since when I use the OriginalGrammarStandaloneSetup it works perfectly fine.

Answer 1

You have to make sure that your sublanguage also invokes the standalone setup of your super language. Usually this is generated in the DocumentationGrammarStandaloneSetupGenerated class, but please make sure that this was properly setup by Xtext. In the end, there should be something like
if (!Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap().containsKey("xtextbin"))
Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap().put(
"xtextbin", new BinaryGrammarResourceFactoryImpl());
in the callchain of your setup's createInjectorAndDoEMFRegistration method.