Monaco-editor: Goto definition (Ctrl + click) works only if definition is in same model

[martin-pabst]

monaco-editor version: 0.20.0
Browser: Chrome
OS: Windows

Reproduction steps:

• Go to playground
• Paste code below
• Run
• ctrl + MouseOver on IdentifierA in line 1
  => Identifier A is blue and underlined; small widget pops up showing reference "another IdentifierA" => OK!

• ctrl left click on IdentifierA in line 1
  => IdentifierA in line 3 blinks and Cursor jumps to line 3 => OK!

• ctrl + MouseOver on IdentifierB in line 2
  => Identifier B is underlined; small widget pops up showing reference "another IdentifierB" => OK!

• ctrl left click on IdentifierB in line 2
  => Nothing happens. Editor should display model2 and Curser should jump to line 1 => Bug!

I was able to fix this bug:
a) insert
editor.setModel(model);
in standaloneCodeServiceImpl.ts after line 43
b) replace
return null;
whith
return monaco.editor.getModels().find(model => model.uri.toString() === resource.toString());
in Method StandaloneCodeEditorServiceImpl.findModel

Instead of b) it would certainly be better to use SimpleEditorModelResolverService, but i don't know how to get a reference of it so i better refrain from making a pull request on base of my amateur work.

By the way:
I'm writing an online-IDE with compiler for my students. Without monaco editor this would not be possible:

Monaco editor is an awesome library, thank you!

Editor Playground html:

<div id="container" style="height:100%;"></div>

Editor Playground css:
none

Editor Playground js:

const editor = monaco.editor.create(document.getElementById("container"), {});

const model1 = monaco.editor.createModel("identifierA\nIdentifierb\nanother IdentifierA", "python", monaco.Uri.from({
    scheme: "inmemory",
    path: "file1.macc",
}))

const model2 = monaco.editor.createModel("another Identifierb", "python", monaco.Uri.from({
    scheme: "inmemory",
    path: "file2.macc",
}))

editor.setModel(model1)

monaco.languages.registerDefinitionProvider("python", {
    provideDefinition: (model, position, token) => {
        if (position.lineNumber == 1) {
            return {
                uri: model1.uri,
                range: {
                    startLineNumber: 3,
                    startColumn: 9,
                    endLineNumber: 3,
                    endColumn: 20
                }
            }
        }

        if (position.lineNumber == 2) {
            return {
                uri: model2.uri,
                range: {
                    startLineNumber: 1,
                    startColumn: 9,
                    endLineNumber: 1,
                    endColumn: 20
                }
            }
        }
    }
});

[spahnke]

I think it would not be a good idea to implement this feature generally; or at least it should be configurable to keep the current behavior. I would assume most use cases use a single editable model (the one that's shown), accompanied by zero or more additional models.

For example: We add several models to the editor (all .js, or .d.ts files) to provide code completion for complex scenarios, but would never ever ever want a user to navigate there in the same editor instance by invoking "Go to definition". Because that would mean we are now in a state that is absolutely meaningless to the user, and additionally there is no way for the user to get back to the old model.

However, I see a need to provide functionality like this - even in our use case. We would like for the user to "Go to definition" for specific models. Not in the same editor instance, but rather in a new tab. Today we accomplish that by hijacking the openEditor function on the StandaloneCodeEditorServiceImpl class. If the original function returns null we just check if it is a valid model to jump to, and then open a new tab displaying that code, but leaving the original editor in the same state.

Playground code:

monaco.editor.createModel("const foo = 1;", "javascript", monaco.Uri.file("foo.js"));

const editor = monaco.editor.create(document.getElementById("container"), {
    value: `function hello() {
    alert('Hello world!');
}
hello();
foo`,
    language: "javascript"
});

const editorService = editor._codeEditorService;
const openEditorBase = editorService.openCodeEditor.bind(editorService);
editorService.openCodeEditor = async (input, source) => {
    const result = await openEditorBase(input, source);
    if (result === null) {
        alert("intercepted")
        console.log("Open definition for:", input);
        console.log("Corresponding model:", monaco.editor.getModel(input.resource));
    }
    return result; // always return the base result
};

By adjusting the code a bit I would assume you could use the same technique to open the found editor model in the same editor instance (the source parameter is a ICodeEditor instance).

The downside is that this is not an official API. So the question is could there be an official API endpoint that enables registering some kind of provider/handler that kicks in when the standard implementation does not find a model (i.e. the if block in my hacky implementation)? If we settle on an approach and I find some time, I would be happy to provide a PR.

Thoughts?

[martin-pabst]

Dear Mr. Pahnke,
thank you for your proposal! I'm able to achieve the desired functionality with this code:

const editorService = editor._codeEditorService;
const openEditorBase = editorService.openCodeEditor.bind(editorService);
editorService.openCodeEditor = async (input, source) => {
    const result = await openEditorBase(input, source);
    if (result === null) {
        alert("intercepted")
        console.log("Open definition for:", input);
        console.log("Corresponding model:", monaco.editor.getModel(input.resource));
        console.log("Source: ", source);
        source.setModel(monaco.editor.getModel(input.resource));
    }
    return result; // always return the base result
};

So an official API endpoint that enables registering some kind of provider/handler that kicks in when the standard implementation does not find a model would be a good solution.