State of Vue I18n kazupon

KAZUPON Vue.js Core Team Member Vue.js Japan User Group Organizer Creator of Vue I18n & Intlify @kazu_pon kazupon

Working at Plaid,inc. One of the largest SaaS Company in Japan i18n of product `KARTE`

Vue I18n

What’s Vue I18n? • Internationalization for Vue.js plugin • Features • Translation • Pluralization • Datetime Format • Number Format • Translation per SFC • … and more!

Official Tooling • Bundler middleware • webpack: @intlify/vue-i18n-loader • rollup: @intlify/rollup-plugin-vue-i18n • vite: @intlify/vite-plugin-vue-i18n

Official Tooling • Vue CLI Plugin • @intlify/vue-cli-plugin-i18n $ vue add i18n Scaffolding Setup

Official Tooling • ESLint Plugin • @intlify/eslint-plugin-vue-i18n

Official Tooling • Vue Jest Processor • vue-i18n-jest • Vue I18n Extensions • @intlify/vue-i18n-extensions • Vue I18n Locale Message Tools • vue-i18n-locale-message • Intlify CLI • @intlify/cli

Third Party Tooling • Nuxt I18n • Babel Edit • i18n Ally • IntlliJ IDEA Plugin • vue-i18n-extract

Vue I18n stats • NPM (Feb 2021) • over 180 releases • 34 Million downloads (total) • Used from over 15,000 packages • JSDelivr • 4 Million downloads / month

Vue I18n stats • Used from over 5,200 Vue / Nuxt Apps (Feb, 2021) Vue Telescope

Vue I18n Histories 2015 2016 2014 2017 2018 2019 2020 Feb Vue v0.8 Oct Vue v1 Sep Vue v2 Sep Vue v3 May Vue I18n v0 Jan Vue I18n v1 June Vue I18n v2 Apr Vue I18n v3 May Vue I18n v4 Feb Vue I18n v5 Apr Vue I18n v6 May Vue I18n v7 June Vue I18n v8 Initial Release! Vue v1 Support! Vue v2 Support! Add many features! - i18n custom block - Datetime Format - Number Format - Component Interpolation - Custom format - SSR - TypeScript type definitions - … and more

Vue I18n Current • Current Version • v8.22.4 • Stable version for Vue 2

Vue I18n has been growing!

… Today

Finally

Vue I18n v9 has been released!! 🎉 🎉 🎉

Vue I18n v9

V9 Development • Dec 20, 2019 • Released Vue 3 initial alpha version • Jan 6, 2020 • Started Vue I18n v9 development repo: https://github.com/intlify/vue-i18n-next vue-i18n-next over 600 commits, 9 related tooling development • Feb, 2021 • Released Vue I18n v9!

Full scratch implementation • The Why • Maintenance and enhancement has becoming very difficult … • By re-designing and re-writing, Vue I18n could get solidify foundation as an i18n library.

Layered modules

Layered modules • Structured with Monorepo packages vue-i18n @intlify/core @intlify/core-base @intlify/message- compiler @intlify/message- resolver @intlify/runtime Entry layer Core layer Utility layer

Layered modules • Better maintainability • More bundle size shavable • More extensible • Expose APIs per package • Low-level i18n APIs: @intlify/core-base • Compiler APIs: @intlify/message-compiler

Hybrid APIs

Hybrid APIs • Composition API • Optimized for Vue 3 Composition API • Legacy API • Almost Compatible v8.x API • Based on Low Level i18n API (@intlify/core-base) Low Level i18n API Composition API Legacy API

Hybrid APIs • Example Composition API Legacy API

Message Compiler

Message Compiler • Compiler for Vue I18n Message Format • Scanner • Tokenizer • Parser • Transformer • Generator • Generate Message Function from Message

Message Compiler • Compile Process ‘Hi, {name} !’ Tokenizer H i , { n a m e } ! Scanner scan & tokenize Hi, { name } ! Tokens Parser Hi, { name } ! syntax analysis type: text value: ‘Hi,’ type: named key: ‘name’ type: text value: ‘ !’ type: message items: […] AST Transformer type: text value: ‘Hi,’ type: named key: ‘name’ type: text value: ‘ !’ type: message items: […] walk & transform Pre-processed AST Generator walk & generate type: text value: ‘Hi,’ type: named key: ‘name’ type: text value: ‘ !’ type: message items: […] Message "function __msg__ (ctx) { … return _normalize([ \\"hi \\”, _interpolate(_named(\\”name\\")), \\” !\\" ]) }" Message Function

Message Compiler • Can detect syntax errors at compilation • Report User-friendly error

Message Compiler • Source-map Support

Message Compiler • Expose Compiler API • Use-cases • Linter: @intlify/eslint-plugin-vue-i18n • CLI: @intlfiy/cli • … and depends on your idea!

Pre-Compilation

Pre-Compilation • Pre-compile locale messages by using official bundler middleware (e.g. @intlify/vue-i18n-loader) Pre-Compile yaml javascript

Pre-Compilation • Improve App performance with reduce locale messages compilation costs String Case Pre-Compilation Case Reduce locale messages compilation costs!

Vue DevTools Integration

Vue Devtools Integration • Extend Component Inspector Local Scope Custom tag

Vue Devtools Integration • i18n Resource Inspector Listed Scopes Inspect Selected Scope

Vue Devtools Integration • Vue I18n Timeline • Events - missing - fallback - message-resolve - message-compilation - message-evaluation - compile-error

Bundle Size Optimization

Bundle Size Optimization • Vue I18n v9 different builds • global build: vue-i18n(.runtime).global(.prod).js • esm-browser build: vue-i18n(.runtime).esm-browser(.prod).js • esm-bundler build: vue-i18n(.runtime).esm-bundler.js • cjs build: vue-i18n.cjs(.prod).js

Bundle Size Optimization • Runtime + Message Compiler vs. Runtime only • Runtime + Message Compiler (Default) vue-i18n.esm-bundler.js • Runtime Only vue-i18n.runtime.esm-bundler.js You can reduce message complier size!

Bundle Size Optimization • Feature Flags • `__VUE_I18N_FULL_INSTALL__` • `true` (default): Vue I18n APIs + built-in components + directive • `false`: Vue I18n APIs • `__VUE_I18N_LEGACY_API__` • `true` (default): Legacy API + Composition API • `false`: Composition API

Bundle Size Optimization • Case: vite-vue-i18n-starter `vendor.xxxx.js` • No Optimization (Full install / Full API / Runtime + Message Compiler) 27.83 KB • Full Optimization: (Composition API / Runtime) 22.00 KB Reduce bundle size about 20% with Tree-Shaking!

New Toolings

New Toolings • Vite Plugin • @intlify/vite-plugin-vue-i18n • Setup Vue 3 Composition API + Vue I18n Composition API • Intlify CLI • @intlify/cli • `compile` command Locale messages pre-compilation

Next Milestone “Beetle” Plan

Message Format Syntax • Enhancement Syntax like ICU message format NOTE: This current syntax is still unstable

Main Packages Improvement • vue-i18n • Type inference for TypeScript • Custom formatter • @intlify/core-base • Low level i18n APIs improvement • @intlify/message-resolver • pluggable resolver support

Tooling Improvement • Bundler middleware • Monorepo management • ESLint Plugin • JSON / YAML parser performance • Vue I18n Processor • vue-jest@v5 support • Intlify CLI • Port from vue-i18n-locale-message

… And • Provide IE 11 Compatibility Build • Move kazupon/vue-i18n repo to intlify org • vue-i18n-next codes to intlify/vue-i18n repo

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https://intilfy.dev Intlify is a project that aims to improve Developer Experience in software internationalization. We will aim to improve the Developer Experience of internationalization by providing libraries, frameworks, and tools that break down barriers to internationalization. Mission “ ”

• Vue I18n is part of Intlify project. • We'll be working on solving i18n problem while also working on the Vue ecosystem. • As Vue I18n is growing, Intlify project member wanted. • If you are interested in intlify, please ask me.

Thanks! https://github.com/sponsors/kazupon