modify source model from edit-label-handler

[rileydanejohnston]

Hello,
I’m trying to get a better understanding of the edit-label-handler so I can modify my source model within the edit-label-handler. My source model has Node objects that have a ‘name’ property. Nodes end up rendering a GNode with a GLabel child, where the ‘name’ property becomes the label text. I’d like to modify the name property in my source model within the edit-label-handler. Here’s my implementation of the edit-label-handler:

 import { ApplyLabelEditOperation } from '@eclipse-glsp/protocol';
 import { GLSPServerError, OperationHandler, toTypeGuard, GNode } from '@eclipse-glsp/server-node';
 import { inject, injectable } from 'inversify';
 import { SourceModelState } from '../model/model-state';

 @injectable()
 export class EditLabelHandler implements OperationHandler {
	readonly operationType = ApplyLabelEditOperation.KIND;

	@inject(SourceModelState)
	protected modelState: SourceModelState;

	execute(operation: ApplyLabelEditOperation): void {
		const index = this.modelState.index;
		const allSourceNodes = this.modelState.sourceNodes;

		// Retrieve the parent node of the label that should be edited
		const indexNode = index.findParentElement(operation.labelId, toTypeGuard(GNode));
		if (indexNode) {
			// find source model match
			const sourceNode = allSourceNodes.find(node => node.id === indexNode.id);
			if (sourceNode) {
				// update source model with new label text
				sourceNode.name = operation.text;
			}
		} else {
			throw new GLSPServerError(`Could not retrieve the parent task for the label with id ${operation.labelId}`);
		}
	}
 }

The GLabel text is updating correctly when I console log it. The GLabel gets updated no matter what is in the edit-label-handler’s execute function (even a console.log with nothing else), which is confusing to me. I have a workaround where I extract the updated text and update the source model in the gmodel-factory, but I imagine I should be able to do this in the edit-label-handler. Is it possible to edit the source model from within the edit-label-handler? Am I missing something?

Other details:

• I’m using a node backend with a vscode client.
• I’ve binded the handler & validator in the module file
• editLabelValidator is firing and returning status 4
• GLabels/GNodes in the graph are editable

[rileydanejohnston]

I've found a solution for this. I went in diagram-module file on the server side and updated the order of the bindings so that the super.configureOperationHandlers(binding) line is last, with my custom handlers coming first like so:

protected override configureOperationHandlers(binding: InstanceMultiBinding<OperationHandlerConstructor>): void {
   binding.add(handler1);
   binding.add(handler2);
   super.configureOperationHandlers(binding);
}

[planger]

Thanks for posting your solution!

Are you extending the [GModelDiagramModule](https://github.com/eclipse-glsp/glsp-server-node/blob/main/packages/server-node/src/gmodel-lib/gmodel-diagram-module.ts)? In this module, the ApplyLabelEditOperationHandler is added. Afaik for operation handlers, the first matching handler is executed. Thus, it would be probably more clean, if you'd remove the ApplyLabelEditOperationHandler and add your handler instead.

protected override configureOperationHandlers(binding: InstanceMultiBinding<OperationHandlerConstructor>): void {
    super.configureOperationHandlers(binding);
    binding.remove(ApplyLabelEditOperationHandler);
    binding.add(handler1);
    binding.add(handler2);
}