Data model

Hexatomic works on instances of a graph-based meta model for linguistic data called Salt.

In Salt, linguistic data is organized in projects:

• A Salt project contains at least one - and often only one - corpus graph.
• A corpus graph contains corpora as nodes.
• The child nodes of a corpus can again be corpora (so-called sub-corpora) and documents.
• Each document has a document graph, which is the model element containing the actual linguistic data:
  • primary data sources (text, audio, or video material), and
  • annotations.

Salt is very powerful in that it is theory-neutral and tagset-independent, and can model a vast variety of linguistic data and annotations.

To find out more about the Salt meta model for linguistic data and its Java API, please refer to the Salt homepage, and the Salt documentation.

Accessing the data model

During runtime, Hexatomic operates on a single Salt project at any one time. The currently opened Salt project is part of the global state of the application, and can be accessed by injecting an instance of the ProjectManager singleton into your code. For an overview of how dependency injection works in Eclipse-based applications such as Hexatomic, see Lars Vogel's tutorial "Dependency injection and Eclipse".

import javax.inject.Inject;
import org.corpus_tools.hexatomic.core.ProjectManager;
import org.corpus_tools.salt.common.SaltProject;

public class MyClass {
	
	@Inject
	private ProjectManager projectManager;
	
	public void execute() {
		SaltProject theProject = projectManager.getProject();
	}
}

Reacting to changes

You can register for any changes on the Salt project (e.g., added annotations to a document), by subscribing to the Topics.ANNOTATION_CHANGED topic, which will be sent by the Eclipse RCP IEventBroker service. After registering your listener, you will receive all updates for all documents and all changes to the project structure. You have to decide in your own code if you need to handle an update, e.g., because it is related to a document you are editing for which the event should trigger redrawing the editor you are implementing. The argument for the Topics.ANNOTATION_CHANGED event is of the type org.corpus_tools.hexatomic.core.undo.ChangeSet and contains a list of all changes. It also has a helper function to test if a given document is affected by its changes.

@Inject
@org.eclipse.e4.core.di.annotations.Optional
private void onDataChanged(@UIEventTopic(Topics.ANNOTATION_CHANGED) Object element) {
  if (element instanceof ChangeSet) {
    ChangeSet changeSet = (ChangeSet) element;
    if (changeSet.containsDocument(
        part.getPersistedState().get(OpenSaltDocumentHandler.DOCUMENT_ID))) {
      // TODO: check graph update is relevant for this editor and update UI
    }
  }
}