Add group root for tree view representation

api/src/engine/connectors/exareme/main.connector.ts

@@ -33,6 +33,7 @@ export default class ExaremeService implements IEngineService {
             id: data.code,
             label: data.label,
             groups: groups,
+            rootGroup: dataToGroup(data.metadataHierarchy),
             datasets: data.datasets ? data.datasets.map(dataToCategory) : [],
             variables: data.metadataHierarchy
               ? this.flattenVariables(data.metadataHierarchy, groups)

api/src/engine/models/domain.model.ts

@@ -6,4 +6,7 @@ import { Group } from './group.model';
 export class Domain extends Group {
   @Field(() => [Category])
   datasets: Category[];
+
+  @Field(() => Group)
+  rootGroup: Group;
 }

api/src/schema.gql

@@ -31,6 +31,7 @@ type Domain {
   groups: [Group!]!
   variables: [Variable!]!
   datasets: [Category!]!
+  rootGroup: Group!
 }
 
 type Query {