@rushstack/webpack4-localization-plugin

Installation

npm install @rushstack/webpack4-localization-plugin --save-dev

Overview

This Webpack plugin produces bundles that have multiple locales' variants of strings embedded. It also has out-of-box support for RESX files in addition to JSON strings files (with the extension .loc.json), including support for generating typings.

Example Plugin Usage

There are three example projects in this repository that make use of this plugin:

• Project 1
  • This project contains two webpack entrypoints (one with an async chunk, one without), without any localized resources
  • The output is a single, non-localized variant
• Project 2
  • This project contains three webpack entrypoints:
    • indexA.ts directly references two .loc.json files and one .resx file, and dynamically imports an async chunk with localized data, and an async chunk without localized data
    • indexB.ts directly references two .loc.json files
    • indexC.ts directly references no localized resources, and dynamically imports an async chunk without localized data
  • The webpack config contains and references Spanish translations for most of the English strings in the resource files
  • The output contains English, Spanish, and "passthrough" localized variants of files that contain localized data, and a non-localized variant of the files that do not contain localized data
• Project 3
  • This project contains four webpack entrypoints:
    • indexA.ts directly references one .loc.json file, one .resx.json file, one .resx file, and one .resjson file, and dynamically imports an async chunk with localized data, and an async chunk without localized data
    • indexB.ts directly references one .loc.json file and one .resx.json file
    • indexC.ts directly references no localized resources, and dynamically imports an async chunk with localized data
    • indexD.ts directly references no localized resources, and dynamically imports an async chunk without localized data
  • The webpack config contains or references Spanish translations for some of the English strings in the resource files
  • The output contains English, Spanish, "passthrough," and two pseudo-localized variants of files that contain localized data, and a non-localized variant of the files that do not contain localized data

.resx vs .loc.json vs .resjson

.resx is an XML format for resource data. It is primarily used in .NET development, and it is supported by some translation services. See an example of a .resx file here. Note that the and elements are not required. Also note that although the .resx supports many different types of localized data including strings and binary data, only strings are supported by this plugin.

.loc.json is a very simple JSON schema for specifying localized string and translator comments. See an example of a .loc.json file here.

.resjson is another simple JSON schema for specifying localized string and translator comments. See here for documentation on .resjson

For most projects, .loc.json is a simpler format to use. However for large projects, projects that already use translation services that support .resx, or engineers who are already experienced .NET developers, .resx may be more convenient.

Plugin

To use the plugin, add it to the plugins array of your Webpack config. For example:

import { LocalizationPlugin } from '@rushstack/webpack4-localization-plugin';

{
  plugins: [
    new LocalizationPlugin( /* options */ )
  ]
}

A note about the dev server: When Webpack is being run by the Webpack dev server, this plugin pipes the strings in the loc files in the source (the .loc.json and the .resx files) to the output without any translations.

Options

localizedData = { }

localizedData.defaultLocale = { }

This option has a required property (localeName), to specify the name of the locale used in the .resx and .loc.json files in the source.

localizedData.defaultLocale.fillMissingTranslationStrings = true | false

If this option is set to true, strings that are missing from localizedData.translatedStrings will be provided by the default locale (the strings in the .resx and .loc.json files in the source). If this option is unset or set to false, an error will be emitted if a string is missing from localizedData.translatedStrings.

localizedData.translatedStrings = { }

This option is used to specify the localization data to be used in the build. This object has the following structure:

• Locale name
  • Compilation context-relative or absolute localization file path
    • Translated strings

For example:

translatedStrings: {
  "en-us": {
    "./src/strings1.loc.json": {
      "string1": "the first string"
    }
  },
  "es-es": {
    "./src/strings1.loc.json": {
      "string1": "la primera cadena"
    }
  }
}

Alternatively, instead of directly specifying the translations, a path to a translated resource file can be specified. For example:

translatedStrings: {
  "en-us": {
    "./src/strings1.loc.json": "./localization/en-us/strings1.loc.json"
  },
  "es-es": {
    "./src/strings1.loc.json": "./localization/es-es/strings1.loc.json"
  }
}

localizedData.resolveMissingTranslatedStrings = (locales: string[], filePath: string) => { ... }

This optional option can be used to resolve translated data that is missing from data that is provided in the localizedData.translatedStrings option. Set this option with a function expecting two parameters: the first, an array of locale names, and second, a fully-qualified path to the localized file in source. The function should return an object with locale names as keys and localized data as values. The localized data value should either be:

• a string: The absolute path to the translated data in .resx or .loc.json format
• an object: An object containing the translated data

Note that these values are the same as the values that can be specified for translations for a localized resource in localizedData.translatedStrings.

If the function returns data that is missing locales or individual strings, the plugin will fall back to the default locale if localizedData.defaultLocale.fillMissingTranslationStrings is set to true. If localizedData.defaultLocale.fillMissingTranslationStrings is set to false, an error will result.

localizedData.passthroughLocale = { }

This option is used to specify how and if a passthrough locale should be generated. A passthrough locale is a generated locale in which each string's value is its name. This is useful for debugging and for identifying cases where a locale is missing.

This option takes two optional properties:

localizedData.passthroughLocale.usePassthroughLocale = true | false

If passthroughLocale.usePassthroughLocale is set to true, a passthrough locale will be included in the output. By default, the passthrough locale's name is "passthrough."

localizedData.passthroughLocale.passthroughLocaleName = '...'

If passthroughLocale.usePassthroughLocale is set to true, the "passthrough" locale name can be overridden by setting a value on passthroughLocale.passthroughLocaleName.

localizedData.pseudolocales = { }

This option allows pseudolocales to be generated from the strings in the default locale. This option takes an option with pseudolocales as keys and options for the pseudolocale package as values.

localizedData.normalizeResxNewlines = 'crlf' | 'lf'

This option allows normalization of newlines in RESX files. RESX files are XML, so newlines can be specified by including a newline in the `` element. For files stored on source control systems, clones on Windows can end up with CRLF newlines and clones on 'nix operating systems can end up with LF newlines. This option can be used to help make compilations run on different platforms produce the same result.

`localizedData.ignoreMissingResxComments = true | false | undefined

If set to true, do not warn on missing RESX element comments.

globsToIgnore = [ ]

This option is used to specify .resx and .loc.json files that should not be processed by this plugin. By default, every .resx, .resx.json, and .loc.json file import is intercepted by this plugin, and an error occurs if translations aren't provided for an intercepted file and the localizedData.defaultLocale.fillMissingTranslationStrings option is set to falsy, or if the file is in an unexpected format. To avoid an error, specify files that should be ignored by this plugin in this property. This is useful if a dependency uses files with a .resx, .resx.json, or .loc.json extension, but are processed in a different way from how this plugin handles localization. For example: globsToIgnore: [ 'node_modules/some-dependency-name/lib/**/*.loc.json' ]

noStringsLocaleName = '...'

The value to replace the [locale] token with for chunks without localized strings. Defaults to "none"

localizationStats = { }

localizationStats.dropPath = '...'

This option is used to designate a path at which a JSON file describing the localized assets produced should be written. If this property is omitted, the stats file won't be written.

The file has the following format:

{
  "entrypoints": {
    "": {
      "localizedAssets": {
        "": "",
        "": ""
      }
    },
    "": {
      "localizedAssets": {
        "": "",
        "": ""
      }
    }
  },
  "namedChunkGroups": {
    "": {
      "localizedAssets": {
        "": "",
        "": ""
      }
    },
    "": {
      "localizedAssets": {
        "": "",
        "": ""
      }
    }
  }
}

localizationStats.callback = (stats) => { ... }

This option is used to specify a callback to be called with the stats data that would be dropped at localizationStats.dropPath after compilation completes.

typingsOptions = { }

This option is used to specify how and if TypeScript typings should be generated for loc files.

It takes two options:

typingsOptions.generatedTsFolder = '...'

This property specifies the folder in which .d.ts files for loc files should be dropped. It is recommended that this be a folder parallel to the source folder, specified in addition to the source folder in the rootDirs tsconfig.json option. The folder specified by this option is emptied when compilation is started.

This property is required if typingsOptions is set.

typingsOptions.sourceRoot = '...'

This optional property overrides the compiler context for discovery of localization files for which typings should be generated.

typingsOptions.exportAsDefault = true | false

If this option is set to true, loc modules typings will be exported wrapped in a default property. This allows strings to be imported by using the import strings from './strings.loc.json'; syntax instead of the import { string1 } from './strings.loc.json'; or the import * as strings from './strings.loc.json'; syntax. This option is not recommended.

Links

• CHANGELOG.md - Find out what's new in the latest version

@rushstack/webpack4-localization-plugin is part of the Rush Stack family of projects.