Javascript 渐进式web应用未捕获(承诺中)类型错误:无法获取
我开始学习PWA(渐进式Web应用程序),但我遇到了问题,控制台“抛出”错误未捕获(承诺中)类型错误:无法获取Javascript 渐进式web应用未捕获(承诺中)类型错误:无法获取,javascript,service-worker,progressive-web-apps,Javascript,Service Worker,Progressive Web Apps,我开始学习PWA(渐进式Web应用程序),但我遇到了问题,控制台“抛出”错误未捕获(承诺中)类型错误:无法获取 addEventListener('fetch', function(event) { event.respondWith( caches.match(event.request) .then(function(response) { if (response) { return response; // if val
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
有人知道原因是什么吗
let CACHE = 'cache';
self.addEventListener('install', function(evt) {
console.log('The service worker is being installed.');
evt.waitUntil(precache());
});
self.addEventListener('fetch', function(evt) {
console.log('The service worker is serving the asset.');
evt.respondWith(fromCache(evt.request));
});
function precache() {
return caches.open(CACHE).then(function (cache) {
return cache.addAll([
'/media/wysiwyg/homepage/desktop.jpg',
'/media/wysiwyg/homepage/bottom2_desktop.jpg'
]);
});
}
function fromCache(request) {
return caches.open(CACHE).then(function (cache) {
return cache.match(request).then(function (matching) {
return matching || Promise.reject('no-match');
});
});
}
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
我认为这是因为你没有后备策略<代码>事件。respondWith附带了一个承诺,如果出现错误,您必须抓住这个承诺
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
因此,我建议您更改以下代码:
self.addEventListener('fetch', function(evt) {
console.log('The service worker is serving the asset.');
evt.respondWith(fromCache(evt.request));
});
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
对这样的事情:
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
注意:缓存有很多策略,我在这里展示的是离线优先的方法。欲了解更多信息,请务必阅读 我找到了同一错误的解决方案,在我的例子中,当服务人员找不到文件*时显示错误,通过在chrome session的开发工具中使用网络进行修复,并确定了服务人员找不到的不存在的文件,并删除了要注册的文件数组
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
'/processos/themes/base/js/processos/step/Validation.min.js',
'/processos/themes/base/js/processos/Acoes.min.js',
'/processos/themes/base/js/processos/Processos.min.js',
'/processos/themes/base/js/processos/jBPM.min.js',
'/processos/themes/base/js/highcharts/highcharts-options-white.js',
'/processos/themes/base/js/publico/ProcessoJsController.js',
// '/processos/gzip_457955466/bundles/plugins.jawrjs',
// '/processos/gzip_N1378055855/bundles/publico.jawrjs',
// '/processos/gzip_457955466/bundles/plugins.jawrjs',
'/mobile/js/about.js',
'/mobile/js/access.js',
*我大胆地为我的解决方案。。。我从一个缓存文件开始,然后添加另一个。。。在我得到一个错误路径之前,还要定义作用域{scope:'/'}或{scope:'./'}-edit by lawrghita我也有同样的错误,在我的例子中,Adblock阻止了对以“ad”(例如/adsomething.php)开头的url的获取。在我的例子中,没有找到要缓存的文件(检查网络控制台),这与相对路径有关,因为我使用的是localhost,而站点位于子目录中,因为我在XAMPP服务器上开发了多个项目
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
所以我改变了
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
let cache_name = 'Custom_name_cache';
let cached_assets = [
'/',
'index.php',
'css/main.css',
'js/main.js'
];
self.addEventListener('install', function (e) {
e.waitUntil(
caches.open(cache_name).then(function (cache) {
return cache.addAll(cached_assets);
})
);
});
下面:注意缓存的\u资产上的“/”
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
let cache_name = 'Custom_name_cache';
let cached_assets = [
'./',
'./index.php',
'./css/main.css',
'./js/main.js'
];
self.addEventListener('install', function (e) {
e.waitUntil(
caches.open(cache_name).then(function (cache) {
return cache.addAll(cached_assets);
})
);
});
在添加或获取任何路径之前,如
/offline.html
或/main.js
缓存文件引用应正确,否则获取将失败。即使一个引用不正确,整个提取也将失败
addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
if (response) {
return response; // if valid response is found in cache return it
} else {
return fetch(event.request) //fetch from internet
.then(function(res) {
return caches.open(CACHE_DYNAMIC_NAME)
.then(function(cache) {
cache.put(event.request.url, res.clone()); //save the response for future
return res; // return the fetched data
})
})
.catch(function(err) { // fallback mechanism
return caches.open(CACHE_CONTAINING_ERROR_MESSAGES)
.then(function(cache) {
return cache.match('/offline.html');
});
});
}
})
);
});
let cache_name = 'Custom_name_cache';
let cached_files = [
'/',
'index.html',
'css/main.css',
'js/main.js'
];
// The reference here should be correct.
self.addEventListener('install', function (e) {
e.waitUntil(
caches.open(cache_name).then(function (cache) {
return cache.addAll(cached_files);
})
);
});
哈哈哈也有同样的问题。使用gitea,回购协议以“Ad”开头。几乎所有页面都以这个异常结束,在我的gitea站点中停用Adblock解决了这个问题!这解决了我两小时后的问题。太谢谢你了,我花了好几天的时间解决这个问题!它就像“.png”而不是“.jpg”SMH一样简单。谢谢截至2021年4月,Chrome最近宣布,这一后备措施将很快成为PWA可安装性的强制性措施。尽管Chrome已经软化了他们的立场,但如果没有实施回退,Chrome仍然会发出各种警告并获取失败