Autocompletion: Merging `override` in config

v6
1

Hi!

I’m working on an app that uses CodeMirror 6 as a markdown editor. It allows users to load custom CodeMirror 6 plugins.

I’m having trouble with multiple extensions trying to provide completions without enabling completion globally. For example,

// A user-provided extension
const ext1 = [
    // Use override to avoid enabling autocompletion for languages loaded
    // into the editor by the main application:
    autocompletion({ override: [source1] }),

    // Also supply language data for the case where another extension enables
    // languagedata-based autocompletion:
    EditorState.languageData.of(() => [{ autocomplete: source1 }]),
];

// Another user-provided extension (would be provided in a separate
// file from ext1).
const ext2 = autocomplete({ override: [ source2, source3 ] });

const editorExtensions  = [
    // ...languageData, etc.
    ext1, ext2
];

// Include editorExtensions in an EditorView.

Currently, this leads to a “merge conflict” error (see demo) when merging completion sources.

I’m wondering what the best way to handle this would be. Ideally, user-provided extensions should (among other things), be able to

  1. Provide autocompletions without enabling languageData-based autocompletion
  2. Optionally enable languageData-based autocomplete
  3. Continue to work if languageData-based autocompletion is enabled by another extension.

One possible solution would be to expose a CodeMirror extension to user plugins that wraps autocompletion. A user-provided CodeMirror extension might then look like this (example with a transactionExtender and Facet implementation):

const { editorCompletionSource, enableLanguageDataAutocomplete } = customCodeMirrorExtensions;
export const userExtension = () => {
  const listCompletion = completeFromList([ "myExtraCompletion1" ])

  return [
    editorCompletionSource.of(listCompletion),
    enableLanguageDataAutocomplete.of(true),
  ];
};

This second solution isn’t ideal though:

  • It requires maintaining a wrapper around autocomplete that might already exist.
  • Users might still try to use autocompletion in their extensions and run into unexpected behavior when multiple autocompletions are loaded.

Questions:

  • Is there a built-in way to merge autocomplete extensions without merge conflict errors?
  • Is there a built-in way to enable/disable completion overrides through CodeMirror Extensions?

Thank you for your time!

2

Don’t use override. Just provide more sources via language data (you can use EditorState.languageData to provide it globally as well).

No. This extension API is not a sandbox API. It assumes callers know what they are doing.

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