Detect Language

v6
1

Any way to check the state’s language facet and determine which language is active?

For instance: state.facet(language) returns the LRLanguage but that doesn’t really contain any identifying information other than directly comparing to a language.

import { language } from '@codemirror/language';
import { cssLanguage } from '@codemirror/lang-css';
import { htmlLanguage } from '@codemirror/lang-html';

function whatLanguage(state){
  let stateLanguage = state.facet(language);
  if ( stateLanguage === cssLangauge ) { ... }
  else if ( stateLanguage === htmlLanguage ) { ... }
  ...
}

That’s cumbersome but kinda works.

However, two cases that would be great to support:

  1. If you’re lazy loading languages via the language-data pack. You don’t directly have a LRLanguage to compare to.
  2. “sub” languages and their parent language: TypeScript, Less, Sass, etc.

Perhaps some metadata on the LRLanguages?

Related Issue: Emmet Plugin can’t detect supported languages

2

Indeed, that’s not something languages provide. But it should be workable to set up your code that adds the language to also add some custom facet that stores a language name alongside it.

3

I do have my own custom facet that stores a usable reference to what language is active for my own purposes, however that doesn’t much help in terms of a general extension like Emmet.

For the author of Emmet, are there any reasonable ways to detect what language is in use to allow for selectively enabling/disabling the extension’s features?

4

Comparing in a way that considers sub-languages equivalent can be done by comparing Language.data (which is copied over to reconfigured versions of a language). For doing the test without having access to the actual language objects, I don’t have a solution.