Ajax Angular 2 HTTP进度条
angular2中目前是否有一种方法可以使用angular2/http模块检索ajax调用的进度(即完成百分比) 我使用以下代码进行HTTP调用:Ajax Angular 2 HTTP进度条,ajax,http,angular,ionic2,Ajax,Http,Angular,Ionic2,angular2中目前是否有一种方法可以使用angular2/http模块检索ajax调用的进度(即完成百分比) 我使用以下代码进行HTTP调用: let body = JSON.stringify(params); let headers = new Headers({ 'Content-Type': 'application/json' }); let options = new RequestOptions({ headers: header
let body = JSON.stringify(params);
let headers = new Headers({ 'Content-Type': 'application/json' });
let options = new RequestOptions({ headers: headers });
this.http.post(url, body, options)
.timeout(10000, new Error('Timeout exceeded during login'))
.toPromise()
.then((res) => {
...
}).catch((err) => {
...
});
目标是编写一个同步系统。帖子将返回大量数据,我想给用户一个同步需要多长时间的指示。您可以利用XHR提供的
onprogress
事件(请参阅此plunkr:)
这样就可以获得有关下载进度的提示。Angular2不支持开箱即用,但您可以通过扩展浏览器xhr
类将其插入:
@Injectable()
export class CustomBrowserXhr extends BrowserXhr {
constructor(private service:ProgressService) {}
build(): any {
let xhr = super.build();
xhr.onprogress = (event) => {
service.progressEventObservable.next(event);
};
return <any>(xhr);
}
}
有关更多详细信息,请参见此问题:
import {Injectable} from "angular2/core";
import {Observable} from "rxjs/Observable";
import {Observer} from "rxjs/Observer";
import {Connection,ConnectionBackend} from "angular2/src/http/interfaces";
import {ReadyState, RequestMethod, ResponseType} from "angular2/src/http/enums";
import {ResponseOptions} from "angular2/src/http/base_response_options";
import {Request} from "angular2/src/http/static_request";
import {Response} from "angular2/src/http/static_response";
import {BrowserXhr} from "angular2/src/http/backends/browser_xhr";
import {Headers} from 'angular2/src/http/headers';
import {isPresent} from 'angular2/src/facade/lang';
import {getResponseURL, isSuccess} from "angular2/src/http/http_utils"
export class MyConnection implements Connection {
readyState: ReadyState;
request: Request;
response: Observable<Response>;
constructor(req: Request, browserXHR: BrowserXhr, baseResponseOptions?: ResponseOptions) {
this.request = req;
this.response = new Observable<Response>((responseObserver: Observer<Response>) => {
let _xhr: XMLHttpRequest = browserXHR.build();
_xhr.open(RequestMethod[req.method].toUpperCase(), req.url);
// save the responses in array
var buffer :string[] = [];
// load event handler
let onLoad = () => {
let body = isPresent(_xhr.response) ? _xhr.response : _xhr.responseText;
//_xhr.respons 1 = "Loading data!"
//_xhr.respons 2 = "Loading data!Ready To Receive Orders."
// we need to fix this proble
// check if the current response text contains the previous then subtract
// NOTE: I think there is better approach to solve this problem.
buffer.push(body);
if(buffer.length>1){
body = buffer[buffer.length-1].replace(buffer[buffer.length-2],'');
}
let headers = Headers.fromResponseHeaderString(_xhr.getAllResponseHeaders());
let url = getResponseURL(_xhr);
let status: number = _xhr.status === 1223 ? 204 : _xhr.status;
let state:number = _xhr.readyState;
if (status === 0) {
status = body ? 200 : 0;
}
var responseOptions = new ResponseOptions({ body, status, headers, url });
if (isPresent(baseResponseOptions)) {
responseOptions = baseResponseOptions.merge(responseOptions);
}
let response = new Response(responseOptions);
//check for the state if not 4 then don't complete the observer
if(state !== 4){
//this will return stream of responses
responseObserver.next(response);
return;
}
else{
responseObserver.complete();
return;
}
responseObserver.error(response);
};
// error event handler
let onError = (err: any) => {
var responseOptions = new ResponseOptions({ body: err, type: ResponseType.Error });
if (isPresent(baseResponseOptions)) {
responseOptions = baseResponseOptions.merge(responseOptions);
}
responseObserver.error(new Response(responseOptions));
};
if (isPresent(req.headers)) {
req.headers.forEach((values, name) => _xhr.setRequestHeader(name, values.join(',')));
}
_xhr.addEventListener('progress', onLoad);
_xhr.addEventListener('load', onLoad);
_xhr.addEventListener('error', onError);
_xhr.send(this.request.text());
return () => {
_xhr.removeEventListener('progress', onLoad);
_xhr.removeEventListener('load', onLoad);
_xhr.removeEventListener('error', onError);
_xhr.abort();
};
});
}
}
@Injectable()
export class MyBackend implements ConnectionBackend {
constructor(private _browserXHR: BrowserXhr, private _baseResponseOptions: ResponseOptions) {}
createConnection(request: Request):MyConnection {
return new MyConnection(request, this._browserXHR, this._baseResponseOptions);
}
}
import {Component, provide} from 'angular2/core';
import {HTTP_PROVIDERS,XHRBackend} from 'angular2/http';
import {MyBackend} from './my_backend';
@Component({
selector: 'my-app',
providers: [
HTTP_PROVIDERS,
MyBackend,
provide(XHRBackend, {useExisting:MyBackend})
]
.
.
.
现在调用http.get将返回一系列响应。我强烈建议使用此选项 否则,与xhr混在一起会让你错过会议、饼干和其他东西 此外,它将更具可移植性,更易于实现(从4.3.0版开始,当使用
@ngular/common/http
中的新HttpClient
时),Angular提供了即时收听进度的功能。您只需按如下方式创建HTTPRequest对象:
import { HttpRequest } from '@angular/common/http';
...
const req = new HttpRequest('POST', '/upload/file', file, {
reportProgress: true,
});
当您订阅请求时,您将在每个进度事件中收到调用的订阅:
http.request(req).subscribe(event => {
// Via this API, you get access to the raw event stream.
// Look for upload progress events.
if (event.type === HttpEventType.UploadProgress) {
// This is an upload progress event. Compute and show the % done:
const percentDone = Math.round(100 * event.loaded / event.total);
console.log(`File is ${percentDone}% uploaded.`);
} else if (event instanceof HttpResponse) {
console.log('File is completely uploaded!');
}
});
更多信息。@Bartek Chichoki的回答是正确的,但对我的案子不起作用。 加上观察:“事件”对我起了作用
const req = new HttpRequest('POST', '/upload/file', file, {
reportProgress: true,
observe: 'events'
});
希望它有帮助我希望可以避免使用XhreQuest:)实现,但对此无能为力;)事实上,Angular2的HTTP支持还不支持它,因此您需要明确依赖XHR…这非常有效,直到您升级到Angular 5,然后包失败,因为它引用了OpaqueToken。我更愿意学习这项技术,而不是复制某人的codesCheck update Angular文档:
const req = new HttpRequest('POST', '/upload/file', file, {
reportProgress: true,
observe: 'events'
});