node.js - 将 JSON 更新到缓存中

问题描述

我目前正在构建一个应用程序，可让您检查 Netflix 上已取消的节目。为了避免为 API 调用付费，我正在运行一个 24 小时增量函数，它将调用的数据存储到 JSON 文件中。JSON 文件然后被发送到前端 (React.js) 并且应该为用户缓存。

我正在尝试的一种解决方法是将获取的服务器数据写入 react/src 文件夹中的 JSON 文件，但我也很难找到任何关于从 React 写入 JSON 文件的好文章。

React 预构建的 serviceworker 已经存储了原始 JSON 文件，但拒绝更新。我找不到任何关于 React serviceworkers 的好文章，只知道如何在 base JS 中操作 serviceworkers。我尝试的所有基础 JS 都失败了，因为 React 需要不同的语法和参数。

后端代码 app.js schedule-node 函数

schedule.scheduleJob('* * */23 * *', function(){
  console.log('Daily API call initiated.');
  unirest.get("https://unogs-unogs-v1.p.rapidapi.com/aaapi.cgi?q=get:exp:US&t=ns&st=adv&p=1")
  .header("X-RapidAPI-Host", "unogs-unogs-v1.p.rapidapi.com")
  .header("X-RapidAPI-Key", `${keys.RICHARD_UNOGS_KEY}`)
  .end(function (result) {
    console.log(result.status, result.headers);
    //console.log(result.body) to see all data
    let data = JSON.stringify(result.body)
    fs.writeFile('./movieData.json', data)
  });
})

app.js 向前端发送数据

app.get('/expiring', (req, res) => {
  res.json(MovieData)
})

调用 JSON 文件的前端代码组件

componentDidMount() {
        let url = "http://localhost:8080/expiring"
        fetch(url)
            .then(response => response.json())
            .then(json => {
                console.log(json)
                this.setState({
                    ...this.state.movies,
                    movies: json
                })
            })
    }

serviceWorker.js

const isLocalhost = Boolean(
  window.location.hostname === 'localhost' ||
    // [::1] is the IPv6 localhost address.
    window.location.hostname === '[::1]' ||
    // 127.0.0.1/8 is considered localhost for IPv4.
    window.location.hostname.match(
      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
    )
);

export function register(config) {
  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
    // The URL constructor is available in all browsers that support SW.
    const publicUrl = new URL(process.env.PUBLIC_URL, window.location.href);
    if (publicUrl.origin !== window.location.origin) {
      // Our service worker won't work if PUBLIC_URL is on a different origin
      // from what our page is served on. This might happen if a CDN is used to
      // serve assets; see https://github.com/facebook/create-react-app/issues/2374
      return;
    }

    window.addEventListener('load', () => {
      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;

      if (isLocalhost) {
        // This is running on localhost. Let's check if a service worker still exists or not.
        checkValidServiceWorker(swUrl, config);

        // Add some additional logging to localhost, pointing developers to the
        // service worker/PWA documentation.
        navigator.serviceWorker.ready.then(() => {
          console.log(
            'This web app is being served cache-first by a service ' +
              'worker. To learn more, visit.......'
          );
        });
      } else {
        // Is not localhost. Just register service worker
        registerValidSW(swUrl, config);
      }
    });
  }
}

function registerValidSW(swUrl, config) {
  navigator.serviceWorker
    .register(swUrl)
    .then(registration => {
      registration.onupdatefound = () => {
        const installingWorker = registration.installing;
        if (installingWorker == null) {
          return;
        }
        installingWorker.onstatechange = () => {
          if (installingWorker.state === 'installed') {
            if (navigator.serviceWorker.controller) {
              // At this point, the updated precached content has been fetched,
              // but the previous service worker will still serve the older
              // content until all client tabs are closed.
              console.log(
                'New content is available and will be used when all ' +
                  'tabs for this page are closed. See https:..........'
              );

              // Execute callback
              if (config && config.onUpdate) {
                config.onUpdate(registration);
              }
            } else {
              // At this point, everything has been precached.
              // It's the perfect time to display a
              // "Content is cached for offline use." message.
              console.log('Content is cached for offline use.');

              // Execute callback
              if (config && config.onSuccess) {
                config.onSuccess(registration);
              }
            }
          }
        };
      };
    })
    .catch(error => {
      console.error('Error during service worker registration:', error);
    });
}

function checkValidServiceWorker(swUrl, config) {
  // Check if the service worker can be found. If it can't reload the page.
  fetch(swUrl)
    .then(response => {
      // Ensure service worker exists, and that we really are getting a JS file.
      const contentType = response.headers.get('content-type');
      if (
        response.status === 404 ||
        (contentType != null && contentType.indexOf('javascript') === -1)
      ) {
        // No service worker found. Probably a different app. Reload the page.
        navigator.serviceWorker.ready.then(registration => {
          registration.unregister().then(() => {
            window.location.reload();
          });
        });
      } else {
        // Service worker found. Proceed as normal.
        registerValidSW(swUrl, config);
      }
    })
    .catch(() => {
      console.log(
        'No internet connection found. App is running in offline mode.'
      );
    });
}

window.addEventListener('fetch', function(event) {
    console.log(event.request.url);
    event.respondWith(
        caches.match(event.request).then(function(response) {
            return response || fetch(event.request);
        })
    );
});

export function unregister() {
  if ('serviceWorker' in navigator) {
    navigator.serviceWorker.ready.then(registration => {
      registration.unregister();
    });
  }
}

我需要更新缓存的 JSON 文件。我做 npm run build 因为 React 不允许服务工作者，在我的 index.js 中我有 serviceworkers.register。缓存最初已更新，但即使清除后也不会使用新的 JSON 文件进行更新。欢迎任何建议。

编辑：通过将从服务器发送到客户端的 JSON 数据存储在 localhost 密钥中，半解决了我的问题。

标签： node.jsjsonreactjsservice-workerprogressive-web-apps

node.js - 将 JSON 更新到缓存中

问题描述

解决方案

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