Angular 4.3.3 HttpClient:如何从响应的标头获取值?
(编辑:VS代码;打字稿:2.2.1)
目的是获取请求响应的标头
假设服务中具有HttpClient的POST请求
import { Injectable
} from "@angular/core";
import {
HttpClient,
HttpHeaders,
} from "@angular/common/http";
@Injectable()
export class MyHttpClientService {
const url = 'url';
const body = {
body: 'the body'
};
const headers = 'headers made with HttpHeaders';
const options = {
headers: headers,
observe: "response", // to display the full response
responseType: "json"
};
return this.http.post(sessionUrl, body, options)
.subscribe(response => {
console.log(response);
return response;
}, err => {
throw err;
});
}
第一个问题是我遇到Typescript错误:
'Argument of type '{ headers: HttpHeaders;
observe: string;
responseType: string;
}' is not assignable to parameter of type'{
headers?: HttpHeaders;
observe?: "body";
params?: HttpParams; reportProgress?: boolean;
respons...'.
Types of property 'observe' are incompatible.
Type 'string' is not assignable to type '"body"'.'
at: '51,49' source: 'ts'
确实,当我转到post()方法的ref时,我指出了这个原型(我使用VS代码)
post(url: string, body: any | null, options: { headers?: HttpHeaders;
observe?: 'body';
params?: HttpParams;
reportProgress?: boolean;
responseType: 'arraybuffer';
withCredentials?: boolean;
}): Observable<ArrayBuffer>;
但是我想要这个重载的方法:
post(url: string, body: any | null, options: { headers?: HttpHeaders;
observe: 'response';
params?: HttpParams;
reportProgress?: boolean;
responseType?: 'json';
withCredentials?: boolean;
}): Observable<HttpResponse<Object>>;
因此,我尝试使用此结构修复此错误:
const options = { headers: headers,
"observe?": "response",
"responseType?": "json",
};
并编译!但是我只是得到json格式的主体请求。
此外,为什么我必须放一个?字段名称末尾的符号?正如我在Typescript网站上看到的那样,该符号应该只是告诉用户它是可选的?
我也尝试使用所有字段,不带和带?分数
this.http.post(url).map(resp => console.log(resp));
Typescript编译器告诉您映射不存在,因为它不是Observable的一部分
我也试过了
import { Response } from "@angular/http";this.http.post(url).post((resp: Response) => resp)
它可以编译,但是得到了不受支持的媒体类型响应。这些解决方案应适用于“ Http”,但不适用于“ HttpClient”。
@Supamiu解决方案也得到了不受支持的媒体类型,因此标题中将出现错误。因此,上面的第二个解决方案(具有Response类型)也应该起作用。但从个性上来说,我认为这不是将“Http”与“ HttpClient”混合使用的好方法,因此我将保留Supamiu的解决方案
回答:
您可以观察到完整的响应,而不仅仅是内容。为此,您必须传递observe: response
到options
函数调用的参数中。
http .get<MyJsonData>('/data.json', {observe: 'response'})
.subscribe(resp => {
// Here, resp is of type HttpResponse<MyJsonData>.
// You can inspect its headers:
console.log(resp.headers.get('X-Custom-Header'));
// And access the body directly, which is typed as MyJsonData as requested.
console.log(resp.body.someField);
});
以上是 Angular 4.3.3 HttpClient:如何从响应的标头获取值? 的全部内容, 来源链接: utcz.com/qa/422202.html