NPM module to externalize and localize VSCode extensions

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87115.2.07 months ago7 years agoMinified + gzip package size for vscode-nls in KB


CommonJS module to support externalization and localization. The module only depends on Node.js however its primary use case is for VSCode extensions.
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// This must be the first import in the main entry file
import * as nls from 'vscode-nls';

let localize = nls.config({ locale: 'de-DE' })();

console.log(localize('keyOne', "Hello World"));
console.log(localize('keyTwo', "Current Date {0}", Date.now()));

The config call configures the nls module and should only be called once in the applications entry point. You pass in the locale you want to use and whether the resolved locale should be cached for all further calls. The config call returns a function which is used to load a message bundle. During development time the argument should stay empty. There is another tool that helps extracting the message from your sources and it creates the message bundles automatically for you. The tool is available here.
In secondary modules loaded from the 'main' module no configuration is necessary. However you still need to load the nls module and load the message bundle. This looks like this:
// In secondary file this import can be at random places.
import * as nls from 'vscode-nls';

let localize = nls.loadMessageBundle();

console.log(localize('keyOne', "Hello World"));

During development time the strings in the code are presented to the user. If the locale is set to 'pseudo' the messages are modified in the following form:



  • Removes injection mechanism due to breaking extensions. Please see Issue #44 for more details.


  • Enable a mechanism for something to inject data into vscode-nls. This will be used by VS Code to inject translations into the nls module so that vscode-nls can work in the web. Context in this PR.



  • Split code into common, node and browser to support using vscode-nls in a Web browser. This is a breaking change and need adoption since the default exports of the module are only exporting the common types. To import the node specific part use vscode-nls\node. To use the browser specific part import vscode-nls\browser.

The browser specific part currently does only support a default language inline in code. There is no support yet to load a different language bundle during runtime. However the split allows to web pack the vscode-nls module.



  • support language and locale when resolving options from VSCODE_NLS_CONFIG setting.


  • make vscode-nls webpack friendly (removal of require calls)
  • narrow type for var args in localize function to string | number | boolean | null | undefined


  • added support to bundle the strings into a single nls.bundle(.${locale})?.json file.
  • added support for VS Code language packs.


  • moved to TypeScript 2.1.5. Adapted to @types d.ts files instead of including typings directly into the repository.


  • based on TypeScript 2.0. Since TS changed the shape of the d.ts files for 2.0.x a major version number got introduce to not
break existing clients using TypeScript 1.8.x.