angular-docs-cn/packages/zone.js/lib/common/fetch.ts

113 lines
3.7 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
/**
* @fileoverview
* @suppress {missingRequire}
*/
Zone.__load_patch('fetch', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
interface FetchTaskData extends TaskData {
fetchArgs?: any[];
}
let fetch = global['fetch'];
if (typeof fetch !== 'function') {
return;
}
const originalFetch = global[api.symbol('fetch')];
if (originalFetch) {
// restore unpatched fetch first
fetch = originalFetch;
}
const ZoneAwarePromise = global.Promise;
const symbolThenPatched = api.symbol('thenPatched');
const fetchTaskScheduling = api.symbol('fetchTaskScheduling');
const fetchTaskAborting = api.symbol('fetchTaskAborting');
const OriginalAbortController = global['AbortController'];
const supportAbort = typeof OriginalAbortController === 'function';
let abortNative: Function|null = null;
if (supportAbort) {
global['AbortController'] = function() {
const abortController = new OriginalAbortController();
const signal = abortController.signal;
signal.abortController = abortController;
return abortController;
};
abortNative = api.patchMethod(
OriginalAbortController.prototype, 'abort',
(delegate: Function) => (self: any, args: any) => {
if (self.task) {
return self.task.zone.cancelTask(self.task);
}
return delegate.apply(self, args);
});
}
const placeholder = function() {};
global['fetch'] = function() {
const args = Array.prototype.slice.call(arguments);
const options = args.length > 1 ? args[1] : null;
const signal = options && options.signal;
return new Promise((res, rej) => {
const task = Zone.current.scheduleMacroTask(
'fetch', placeholder, { fetchArgs: args } as FetchTaskData,
() => {
let fetchPromise;
let zone = Zone.current;
try {
(zone as any)[fetchTaskScheduling] = true;
fetchPromise = fetch.apply(this, args);
} catch (error) {
rej(error);
return;
} finally {
(zone as any)[fetchTaskScheduling] = false;
}
if (!(fetchPromise instanceof ZoneAwarePromise)) {
let ctor = fetchPromise.constructor;
if (!ctor[symbolThenPatched]) {
api.patchThen(ctor);
}
}
fetchPromise.then(
(resource: any) => {
if (task.state !== 'notScheduled') {
task.invoke();
}
res(resource);
},
(error: any) => {
if (task.state !== 'notScheduled') {
task.invoke();
}
rej(error);
});
},
() => {
if (!supportAbort) {
rej('No AbortController supported, can not cancel fetch');
return;
}
if (signal && signal.abortController && !signal.aborted &&
typeof signal.abortController.abort === 'function' && abortNative) {
try {
(Zone.current as any)[fetchTaskAborting] = true;
abortNative.call(signal.abortController);
} finally {
(Zone.current as any)[fetchTaskAborting] = false;
}
} else {
rej('cancel fetch need a AbortController.signal');
}
});
if (signal && signal.abortController) {
signal.abortController.task = task;
}
});
};
});