Xtext. Get object by string name

Question

Has some lang like this.

language sample.linking.SampleLang;
generate SampleLang "http://sample/linking/samplelang/v1"
Model:
    entity_node = Entity
;

Entity:
    type = ('blabla1' | 'blabla2') ':' name = ID (annotation = Annotation)? '{'
    (parts += EntityPart)*
    '}'
;

Annotation:
    'deprecated' ( '->' name = ID )?
;

//SomeOtherRools
EntityPart:
    'createNewEntity' '(' entity=STRING ')'
;

I have multiple files, which must be checked

name1.ext
blabla2:name1
{
    ...
}

name2.ext
blabla2:name2 deprecated -> name1
{
    ...
}

name3.ext
blabla1:name3
{
    createNewEntity("name2") - show warning about deprecation
    createNewEntity("name1")
}

Need to check is Entity, which I'm try to "create" from some other entity deprecated or not. Can't do it through the cross-reference, because I've must specify the name by string. How can I write checker for this situation?

@Check
def checkDeprecation(EntityPart entityPart) {
    /*???*/
}

can you give some more hints? what is the search scope? same file - all files? what is the search criteria? why does STRING prevent you from cross referencing (christiandietrich.wordpress.com/2015/03/19/…) — Christian Dietrich
Add some edits to post...I've try to change rule EntityPart: 'createNewEntity' '(' entity=STRING ')'; to EntityPart: 'createNewEntity' '(' entity=[Entity|STRING] ')'; and it's always show "Couldn't resolve reference to Entity"(Also try to change Entity rule to use name = STRING with same result) — ArchCC
(p.s. i could not reproduce it by simply chaning the grammar) — Christian Dietrich
This is link to test project with grammar dropbox.com/s/6tef8czoquv6mi9/testGrammarProject.zip?dl=0 — ArchCC

ArchCC ArchCC · Accepted Answer · 2016-09-28T16:18:49

As Christian Dietrich suggest in comment for such task EntityPart can be changed to

EntityPart:
    'createNewEntity' '(' entity=[Entity|STRING] ')'
;

and add to *validator.xtend

   @Check
   def checkDeprecation(EntityPart entityPart) {
      if(entityPart.getEntity().getAnnotation() != null) {
          var warningString = "Usage of deprecated entity";
          if(entityPart.getEntity().getAnnotation().name != null) {
               warningString = "Usage of deprecated entity, use "+entityPart.getEntity().getAnnotation().name+" instead"
          }
          warning(warningString, null);
      }
   }

Why this may not work...

For Eclipse you need:

xtext project nature
enabled Project - Properties - Builders - Xtext Project Puilder
enabled Project - Build Automatically

For Intellj Idea you need:

facet of you'r dsl lang on module
work only under folders marked as source

Xtext. Get object by string name

1 Answers