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meritkollen/html/cache-polyfill.js
2019-11-04 11:58:46 +01:00

101 lines
2.9 KiB
JavaScript

/*
*
* Air Horner
* Copyright 2015 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*
*/
if (!Cache.prototype.add) {
Cache.prototype.add = function add(request) {
return this.addAll([request]);
};
}
if (!Cache.prototype.addAll) {
Cache.prototype.addAll = function addAll(requests) {
var cache = this;
// Since DOMExceptions are not constructable:
function NetworkError(message) {
this.name = 'NetworkError';
this.code = 19;
this.message = message;
}
NetworkError.prototype = Object.create(Error.prototype);
return Promise.resolve().then(function() {
if (arguments.length < 1) throw new TypeError();
// Simulate sequence<(Request or USVString)> binding:
var sequence = [];
requests = requests.map(function(request) {
if (request instanceof Request) {
return request;
}
else {
return String(request); // may throw TypeError
}
});
return Promise.all(
requests.map(function(request) {
if (typeof request === 'string') {
request = new Request(request);
}
var scheme = new URL(request.url).protocol;
if (scheme !== 'http:' && scheme !== 'https:') {
throw new NetworkError("Invalid scheme");
}
return fetch(request.clone());
})
);
}).then(function(responses) {
// TODO: check that requests don't overwrite one another
// (don't think this is possible to polyfill due to opaque responses)
return Promise.all(
responses.map(function(response, i) {
return cache.put(requests[i], response);
})
);
}).then(function() {
return undefined;
});
};
}
if (!CacheStorage.prototype.match) {
// This is probably vulnerable to race conditions (removing caches etc)
CacheStorage.prototype.match = function match(request, opts) {
var caches = this;
return this.keys().then(function(cacheNames) {
var match;
return cacheNames.reduce(function(chain, cacheName) {
return chain.then(function() {
return match || caches.open(cacheName).then(function(cache) {
return cache.match(request, opts);
}).then(function(response) {
match = response;
return match;
});
});
}, Promise.resolve());
});
};
}