Javascript 如何将服务人员预抓取与跨导航抓取结合起来?
我尝试使用“预取”和“收集”技术在SPA应用程序上缓存js、CSS和内容 对于预取脚本,我尝试了类似以下代码片段的代码:Javascript 如何将服务人员预抓取与跨导航抓取结合起来?,javascript,google-chrome,caching,asynchronous,service-worker,Javascript,Google Chrome,Caching,Asynchronous,Service Worker,我尝试使用“预取”和“收集”技术在SPA应用程序上缓存js、CSS和内容 对于预取脚本,我尝试了类似以下代码片段的代码: self.addEventListener('install',函数(事件){ var now=Date.now(); 变量urlsToPrefetch=[ “static/pre_fetched.txt”, “static/pre_fetched.html” ]; event.waitill( 缓存。打开(当前缓存。预取)。然后(函数(缓存){ var cacheProm
self.addEventListener('install',函数(事件){
var now=Date.now();
变量urlsToPrefetch=[
“static/pre_fetched.txt”,
“static/pre_fetched.html”
];
event.waitill(
缓存。打开(当前缓存。预取)。然后(函数(缓存){
var cachePromises=urlsToPrefetch.map(函数(urlToPrefetch){
var url=新url(urlToPrefetch,location.href);
url.search+=(url.search?'&':'?')+“缓存半身像='+现在;
var request=新请求(url,{mode:'no cors'});
返回fetch(请求)。然后返回函数(响应){
如果(response.status>=400){
抛出新错误('请求'+urlToPrefetch+
“失败,状态为”+响应。状态文本);
}
返回cache.put(urlToPrefetch,response);
}).catch(函数(错误){
console.error('由于'+错误而未缓存'+urlToPrefetch+');
});
});
返回Promise.all(cachePromises).then(function(){
log('Pre-fetching complete');
});
}).catch(函数(错误){
console.error('预取失败:',错误);
})
);
});代码>我没有找到任何参考来确认我的解决方案,但是,它是有效的
解决方案是创建2个不同的缓存,并“规范化”请求将其克隆到syntetic请求中,删除所有引用,只保留基本的:
var CURRENT_CACHES = {
'prefetch-cache': 'prefetch-cache-v' + CACHE_VERSION, //Prefetch cach
'general-cache': 'general-cache-v' + CACHE_VERSION,
};
预回迁缓存
负责存储我想要在我的服务人员上预回迁的所有文件,而普通缓存则用于所有其他文件(当您有SPA并且想要累积一些请求,如翻译文件、js组件、css和其他内容时,这是有意义的)
您可以使用要预回迁的所有文件的URI创建一个数组:
var urlsToPrefetch = [
//JS
"plugin/angular/angular.min.js", "plugin/requirejs/require.min.js","app/main.js","app/app.js","app/includes.js"
//CSS
,"styles/css/print.css","styles/css/bootstrap.css","styles/css/fixes.css",
//Html
,"app/layout/partials/menu.tpl.html", "app/layout/public.tpl.html",
//JSON
,"app/i18n/languages.json","app/i18n/pt-br.json", "app/i18n/en.json"
];
在install event中,您应该为此阵列中的所有文件创建新请求,并将其存储到预回迁缓存中:
self.addEventListener('install', function (event) {
logger && console.log('Handling install event:', event);
//var now = Date.now();
// All of these logging statements should be visible via the "Inspect" interface
// for the relevant SW accessed via chrome://serviceworker-internals
if (urlsToPrefetch.length > 0) {
logger && console.log('Handling install event. Resources to prefetch:', urlsToPrefetch.length , "resources");
event.waitUntil(
caches.open(CURRENT_CACHES['prefetch-cache']).then(function (cache) {
var cachePromises = urlsToPrefetch.map(function (urlToPrefetch) {
urlToPrefetch += '?v=' + CACHE_VERSION;
// This constructs a new URL object using the service worker's script location as the base
// for relative URLs.
//var url = new URL(urlToPrefetch + '?v=' + CACHE_VERSION, location.href);
var url = new URL(urlToPrefetch, location.href);
// Append a cache-bust=TIMESTAMP URL parameter to each URL's query string.
// This is particularly important when precaching resources that are later used in the
// fetch handler as responses directly, without consulting the network (i.e. cache-first).
// If we were to get back a response from the HTTP browser cache for this precaching request
// then that stale response would be used indefinitely, or at least until the next time
// the service worker script changes triggering the install flow.
//url.search += (url.search ? '&' : '?') + 'v=' + CACHE_VERSION;
// It's very important to use {mode: 'no-cors'} if there is any chance that
// the resources being fetched are served off of a server that doesn't support
// CORS (http://en.wikipedia.org/wiki/Cross-origin_resource_sharing).
// In this example, www.chromium.org doesn't support CORS, and the fetch()
// would fail if the default mode of 'cors' was used for the fetch() request.
// The drawback of hardcoding {mode: 'no-cors'} is that the response from all
// cross-origin hosts will always be opaque
// (https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#cross-origin-resources)
// and it is not possible to determine whether an opaque response represents a success or failure
// (https://github.com/whatwg/fetch/issues/14).
var request = new Request(url, {mode: 'no-cors'});
return fetch(request).then(function (response) {
logger && console.log('Add to Cache (Prefetch)', url.href);
if (!response || response.status !== 200 || response.type !== 'basic') {
throw new Error('request for ' + urlToPrefetch +
' failed with status ' + response.statusText);
}
//var responseToCache = response.clone();
// Use the original URL without the cache-busting parameter as the key for cache.put().
// return cache.put(urlToPrefetch, responseToCache);
return cache.put(urlToPrefetch, response);
}).catch(function (error) {
logger && console.error('Not caching ' + urlToPrefetch + ' due to ' + error);
});
});
return Promise.all(cachePromises).then(function () {
logger && console.log('Pre-fetching complete.');
});
}).catch(function (error) {
logger && console.error('Pre-fetching failed:', error);
}));
}
// Perform install steps
// if (urlsToPrefetch.length > 0) {
// event.waitUntil(
// caches.open(CURRENT_CACHES['perma-cache'])
// .then(function (cache) {
// return cache.addAll(urlsToPrefetch);
// })
// );
// }
// `skipWaiting()` forces the waiting ServiceWorker to become the
// active ServiceWorker, triggering the `onactivate` event.
// Together with `Clients.claim()` this allows a worker to take effect
// immediately in the client(s).
return self.skipWaiting();
});
对于将来将存储在缓存中的所有其他文件,您必须将其声明为fetch event listener,并将此请求存储到常规缓存中:
self.addEventListener('fetch', function (event) {
//console.log(event);
if (event.request.method === "GET") {
var qSFilter = "" + ((event.request.url).split('?'))[0];//Filtrar Quetry Stirng
//console.log(event.request.url, qSFilter, qSFilter.split(CACHE_SCOPE), CACHE_SCOPE);
var leUrl = (qSFilter.split(CACHE_SCOPE))[1];
//Is possible to implement some logic to skip backend calls and other uncachable calls
if (/^(app|style|plugin).*(js|css|html|jpe?g|png|gif|json|woff2?)$/.test(leUrl)
|| /^backend\/server\/file\/i18n\/((?!client).+)\//.test(leUrl)
|| /^backend\/server\/static\/images\/.*$/.test(leUrl)
|| /^backend\/server\/static\/style.*$/.test(leUrl)
) {
var url = new URL(leUrl + '?v=' + CACHE_VERSION, location.href);
var synthetic = new Request(url, {mode: 'no-cors'});
//console.log(event.request,response.clone(),synthetic);
event.respondWith(
// caches.match(event.request)
caches.match(synthetic)
.then(function (response) {
// Cache hit - return response
if (response) {
logger && console.log('From Cache', event.request.url);
return response;
}
// IMPORTANT: Clone the request. A request is a stream and
// can only be consumed once. Since we are consuming this
// once by cache and once by the browser for fetch, we need
// to clone the response
var fetchRequest = event.request.clone();
return fetch(fetchRequest).then(
function (response) {
// Check if we received a valid response
if (!response || response.status !== 200 || response.type !== 'basic') {
return response;
}
// IMPORTANT: Clone the response. A response is a stream
// and because we want the browser to consume the response
// as well as the cache consuming the response, we need
// to clone it so we have 2 stream.
var responseToCache = response.clone();
caches.open(CURRENT_CACHES['general-cache'])
.then(function (cache) {
try {
logger && console.log('Add to Cache', event.request.url, qSFilter,leUrl);
cache.put(event.request, responseToCache);
} catch (e) {
console.error(e);
}
});
return response;
}
);
})
);
}
}
});
可在此处访问完整的工作脚本: