src/content/guides/progressive-web-application.md 翻译

src/content/guides/progressive-web-application.md

@@ -7,16 +7,16 @@ contributors:
 
 T> 本指南继续沿用[管理输出](/guides/output-management)中的代码示例。
 
-Progressive Web Applications (or PWAs) are web apps that deliver an experience similar to native applications. There are many things that can contribute to that. Of these, the most significant is the ability for an app to be able to function when __offline__. This is achieved through the use of a web technology called [Service Workers](https://developers.google.com/web/fundamentals/primers/service-workers/).
+渐进式网络应用程序(Progressive Web Application - PWA)，是一种可以提供类似于原生应用程序(native app)体验的网络应用程序(web app)。PWA 可以用来做很多事。其中最重要的是，在__离线(offline)__时应用程序能够继续运行功能。这是通过使用名为 [Service Workers](https://developers.google.com/web/fundamentals/primers/service-workers/) 的网络技术来实现的。
 
-This section will focus on adding an offline experience to our app. We'll achieve this using a Google project called [Workbox](https://github.com/GoogleChrome/workbox) which provides tools that help make offline support for web apps easier to setup.
+本章将重点介绍，如何为我们的应用程序添加离线体验。我们将使用名为 [Workbox](https://github.com/GoogleChrome/workbox) 的 Google 项目来实现此目的，该项目提供的工具可帮助我们更轻松地配置 web app 的离线支持。
 
 
-## We Don't Work Offline Now
+## 现在我们并没有离线环境下运行过
 
-So far, we've been viewing the output by going directly to the local file system. Typically though, a real user accesses a web app over a network; their browser talking to a __server__ which will serve up the required assets (e.g. `.html`, `.js`, and `.css` files).
+到目前为止，我们一直是直接查看本地文件系统的输出结果。通常情况下，真正的用户是通过网络访问网络应用程序；用户的浏览器会与一个提供所需资源（例如，`.html`, `.js` 和 `.css` 文件）的__服务器__通讯。
 
-So let's test what the current experience is like using a simple server. Let's use the [http-server](https://www.npmjs.com/package/http-server) package: `npm install http-server --save-dev`. We'll also amend the `scripts` section of our `package.json` to add in a `start` script:
+那么让我们来使用一个简易服务器，搭建出我们所需的离线体验。我们将使用 [http-server](https://www.npmjs.com/package/http-server) package 包：`npm install http-server --save-dev`。还要修改 `package.json` 的 `scripts` 部分，来添加一个 `start` 脚本：
 
 __package.json__
 
@@ -32,27 +32,27 @@ __package.json__
 }
 ```
 
-If you haven't previously done so, run the command `npm run build` to build your project. Then run the command `npm start`. This should produce the following output:
+如果你之前没有操作过，请运行命令 `npm run build` 来构建你的项目。然后运行命令 `npm start`。这应该输出以下：
 
 ``` bash
 > http-server dist
 
-Starting up http-server, serving dist
-Available on:
+启动 http-server，服务目录是 dist
+可以访问：
   http://xx.x.x.x:8080
   http://127.0.0.1:8080
   http://xxx.xxx.x.x:8080
-Hit CTRL-C to stop the server
+按下 CTRL-C 停止服务
 ```
 
-If you open your browser to `http://localhost:8080` (i.e. `http://127.0.0.1`) you should see your webpack application being served up from the `dist` directory. If you stop the server and refresh, the webpack application is no longer available.
+如果你打开浏览器访问 `http://localhost:8080` (即 `http://127.0.0.1`)，你应该会看到在 `dist` 目录创建出服务，并可以访问 webpack 应用程序。如果停止服务器然后刷新，则 webpack 应用程序不再可访问。
 
-This is what we aim to change. Once we reach the end of this module we should be able to stop the server, hit refresh and still see our application.
+这就是我们最终要改变的现状。在本章结束时，我们应该要实现的是，停止服务器然后刷新，仍然可以查看应用程序正常运行。
 
 
-## Adding Workbox
+## 添加 Workbox
 
-Let's add the Workbox webpack plugin and adjust the `webpack.config.js` file:
+添加 workbox-webpack-plugin 插件，并调整 `webpack.config.js` 文件：
 
 ``` bash
 npm install workbox-webpack-plugin --save-dev
@@ -79,8 +79,8 @@ __webpack.config.js__
 -   })
 +   }),
 +   new WorkboxPlugin({
-+     // these options encourage the ServiceWorkers to get in there fast
-+     // and not allow any straggling "old" SWs to hang around
++     // 这些选项帮助 ServiceWorkers 快速启用
++     // 不允许遗留任何“旧的” ServiceWorkers
 +     clientsClaim: true,
 +     skipWaiting: true
 +   })
@@ -92,7 +92,7 @@ __webpack.config.js__
   };
 ```
 
-With that in place, let's see what happens when we do an `npm run build`:
+有了 Workbox，我们再看下执行 `npm run build` 时会发生什么：
 
 ``` bash
 clean-webpack-plugin: /mnt/c/Source/webpack-follow-along/dist has been removed.
@@ -117,14 +117,14 @@ Child html-webpack-plugin for "index.html":
         + 2 hidden modules
 ```
 
-As you can see, we now have 2 extra files being generated; `sw.js` and the more verbose `precache-manifest.b5ca1c555e832d6fbf9462efd29d27eb.js`. `sw.js` is the Service Worker file and `precache-manifest.b5ca1c555e832d6fbf9462efd29d27eb.js` is a file that `sw.js` requires so it can run. Your own generated files will likely be different; but you should have an `sw.js` file there.
+现在你可以看到，生成了 2 个额外的文件：`sw.js` 和体积很大的 `precache-manifest.b5ca1c555e832d6fbf9462efd29d27eb.js`。`sw.js` 是 Service Worker 文件，`precache-manifest.b5ca1c555e832d6fbf9462efd29d27eb.js` 是 `sw.js` 引用的文件，所以它也可以运行。可能在你本地生成的文件会有所不同；但是你那里应该会有一个 `sw.js` 文件。
 
-So we're now at the happy point of having produced a Service Worker. What's next?
+所以，值得高兴的是，我们现在已经创建出 Service Worker 的高兴点。接下来该做什么？
 
 
-## Registering Our Service Worker
+## 注册我们的 Service Worker
 
-Let's allow our Service Worker to come out and play by registering it. We'll do that by adding the registration code below:
+让我们将注册 Service Worker，使其出场并开始表演。通过添加以下注册代码来完成此操作：
 
 __index.js__
 
@@ -143,15 +143,19 @@ __index.js__
 + }
 ```
 
-Once more `npm run build` to build a version of the app including the registration code. Then serve it with `npm start`. Navigate to `http://localhost:8080` and take a look at the console. Somewhere in there you should see:
+再次运行 `npm build build` 来构建包含注册代码版本的应用程序。然后用 `npm start` 启动服务。访问 `http://localhost:8080` 并查看 console 控制台。在那里你应该看到：
 
 ``` bash
 SW registered
 ```
 
-Now to test it. Stop your server and refresh your page. If your browser supports Service Workers then you should still be looking at your application. However, it has been served up by your Service Worker and __not__ by the server.
+现在来进行测试。停止服务器并刷新页面。如果浏览器能够支持 Service Worker，你应该可以看到你的应用程序还在正常运行。然而，服务器已经__停止__了服务，此刻是 Service Worker 在提供服务。
 
 
-## Conclusion
+## 结论
 
-You have built an offline app using the Workbox project. You've started the journey of turning your web app into a PWA. You may now want to think about taking things further. A good resource to help you with that can be found [here](https://developers.google.com/web/progressive-web-apps/).
+你已经使用 Workbox 项目构建了一个离线应用程序。开始进入将 web app 改造为 PWA 的旅程。你现在可能想要考虑下一步做什么。在这里的[谷歌文档](https://developers.google.com/web/progressive-web-apps/)中可以找到一些不错的资源。
+
+***
+
+> 原文：https://webpack.js.org/guides/progressive-web-application/