[json] Allow extensions to enable the builtin json-language-features extension on their own personal json languageId

[RedCMD]

Currently the builtin json extension supports the language ids json and jsonc
It would be nice if other extensions could add their own languageId to the list

from my testing, simply allowing the possibility to add languages to the documentSelector will work

vscode/extensions/json-language-features/client/src/jsonClient.ts

Line 150 in 55c1e84

const documentSelector = ['json', 'jsonc'];

and also modifying the "activationEvents"

vscode/extensions/json-language-features/package.json

Lines 14 to 17 in bdc113f

	"activationEvents": [
	"onLanguage:json",
	"onLanguage:jsonc"
	],

also very closely related @jeff-hykin
the language Code Snippets does not have the json language server enabled

[aeschli]

For html we support something called language participants:
A language can declare a set of features they want to use from html:
#156200

If that's useful, I'm happy to take a PR for JSON.

But maybe first. may I ask what kind of language that is?

[RedCMD]

But maybe first. may I ask what kind of language that is?

Syntax highlighter for VSCodes json TextMate files
https://marketplace.visualstudio.com/items?itemName=RedCMD.tmlanguage-syntax-highlighter

also the new code-snippets edition would benefit from having the json lanuage features (and JSONL)

but....
would that disable my extension's additional language features?

[aeschli]

Ok I see. No, your proposals would be merged with the proposals from the lJSON anguage server. But you might get conflicting proposals unless you can tune the schema the way you want it.

An alternative is to not define a new language but keep it as JSON.
Use additional providers for diagnostics and semantic highlighting instead of your own grammar.

[RedCMD]

yeah, I'll make the schem handle the basics and let my language server handle the rest

switching to solely using semantic highlighting instead of textmate isn't an option for me
as semantic's cant handle bracket pair matching
and I think the string scope from json disables "autoClosingPairs" (cant re-enable with semantic's)
and I like the idea of textmate grammars highlighting textmate grammars

I'll look into making a PR soon

[andreamah]

@aeschli Do you have some minimal steps to verify this?

[RedCMD]

place this in an extensions package.json file
update languageId with a language to target
open a file with that language set
notice how all the json language features are available
Intellisense, formatting, diagnostics etc

"main": "",
"extensionDependencies": [
	"vscode.json-language-features"
],
"contributes": {
	"jsonLanguageParticipants": [
		{
			"languageId": "foobar"
		}
	]
} 

extensionDependencies activates the json-language-features extension
main is required for extensionDependencies to work