Monaco-editor: Get started with DocumentFormattingEditProvider

[chengtie]

I am trying to add a formatting to a custom language in Monaco Editor. It seems that we could use monaco.languages.registerDocumentFormattingEditProvider.

As an example, I have made a working plunker. Now I want to add a very simple formatting rule to the whole document: add one newline after each error log. But I don't know how to write the provider in mySpecialLanguage.js:

monaco.languages.registerDocumentFormattingEditProvider('mySpecialLanguage', { provideDocumentFormattingEdits: function (model, options, token) { console.log("here") // which is well printed // should return a value of type TextEdit[], but I don't know how to construct one } })

provideDocumentFormattingEdits should return a value of type TextEdit[], where TextEdit is specified here. However, I cannot find enough code samples of constructing TextEdit in Monaco Editor (there are some examples for VSCode). Could anyone point me to some samples and help me get started?

[rcjsuen]

@chengtie A TextEdit is just an interface definition so you can just create a regular ol' JavaScript object with property names that match the interface.

return [
  {
    range: {
      startLineNumber: 1,
      startColumn: 1,
      endLineNumber: 1,
      endColumn: 1
    },
    text: "a"
  }
];

[chengtie]

@rcjsuen thank you for your help. I just inserted your code into this plunker, the text is supposed to change, right? I don't see any change in the preview...

[rcjsuen]

@chengtie It works fine for me. If you click in your editor and hit Alt+Shift+F or bring up the context menu and click on the 'Format Document' menu item, the document will be modified.

[chengtie]

@rcjsuen ok... I did not know we can trigger the formatter like that... it works, thank you very much...

[chengtie]

@rcjsuen Do you happen to have documentation or samples about writing provideDocumentFormattingEdits?

[rcjsuen]

@chengtie No, I don't. If you describe your problem here perhaps someone can help you.

Alternatively, you can try asking for help on Stack Overflow.