【问题标题】:Angular2 Provide Custom Http Not WorkingAngular2 提供自定义 Http 不起作用
【发布时间】:2016-09-09 21:30:03
【问题描述】:

我们需要一个全局空间来捕获 http 401,403 和 500 响应。我查看了一些教程并尝试了一种扩展 http 的方法。这是我的自定义 HTTP(大部分是从网上复制的)

import { Http, ConnectionBackend, Request, RequestOptions, RequestOptionsArgs, Response, Headers} from '@angular/http';
import { Router} from '@angular/router';
import { Injectable} from '@angular/core';
import { Observable} from 'rxjs/Rx';

@Injectable()


export class CustomHttp extends Http {

    constructor(backend: ConnectionBackend, defaultOptions: RequestOptions, private _router : Router) {
        super(backend, defaultOptions);
    }

    request(url: string | Request, options?: RequestOptionsArgs): Observable<Response> {
        return this.intercept(super.request(url, options));
    }

    get(url: string, options?: RequestOptionsArgs): Observable<Response> {
        return this.intercept(super.get(url, options));
    }

    post(url: string, body: string, options?: RequestOptionsArgs): Observable<Response> {
        return this.intercept(super.post(url, body, this.getRequestOptionArgs(options)));
    }

    put(url: string, body: string, options?: RequestOptionsArgs): Observable<Response> {
        return this.intercept(super.put(url, body, this.getRequestOptionArgs(options)));
    }

    delete(url: string, options?: RequestOptionsArgs): Observable<Response> {
        return this.intercept(super.delete(url, options));
    }

    getRequestOptionArgs(options?: RequestOptionsArgs): RequestOptionsArgs {
        if (options == null) {
            options = new RequestOptions();
        }
        if (options.headers == null) {
            options.headers = new Headers();
        }
        options.headers.append('Content-Type', 'application/json');
        return options;
    }

    intercept(observable: Observable<Response>): Observable<Response> {
        return observable.catch((err, source) => {
            console.log('CustomHttp Error status:  ' + err.status);
            return Observable.throw(err); 
        });
    }

}

这是我如何引导我的应用程序并尝试用我的实现替换默认 HTTP:

import { bootstrap }    from '@angular/platform-browser-dynamic';
import { AppComponent } from './app.component';
import { HTTP_PROVIDERS, Http, XHRBackend, RequestOptions} from '@angular/http';
import { ROUTER_DIRECTIVES, Router } from '@angular/router';
import { APP_ROUTER_PROVIDERS  } from './app.routes';
import { provide, PLATFORM_DIRECTIVES} from '@angular/core';
import { LocationStrategy, HashLocationStrategy } from '@angular/common';
import { CustomHttp } from './utils/http/customhttp';


    bootstrap(AppComponent, [
        APP_ROUTER_PROVIDERS,
        HTTP_PROVIDERS,
        provide(LocationStrategy, { useClass: HashLocationStrategy }),
        provide(PLATFORM_DIRECTIVES, { useValue: [ROUTER_DIRECTIVES], multi: true }),
        provide( Http, {
            useFactory: (xhrBackend: XHRBackend, requestOptions: RequestOptions, router: Router) => new CustomHttp(xhrBackend, requestOptions, router),
            deps: [XHRBackend, RequestOptions, Router]
        }),
    ]);

没有编译错误,但是当我尝试使用默认提供程序而不是我的实现发出一些 http 请求时。我知道这一点是因为我故意调用了一个返回 500 的 webapi 端点,并且没有设置到我的 catch 子句中并编写日志语句。

这是我的 js 依赖项:

 "dependencies": {
    "@angular/common": "2.0.0-rc.4",
    "@angular/compiler": "2.0.0-rc.4",
    "@angular/core": "2.0.0-rc.4",
    "@angular/forms": "0.2.0",
    "@angular/http": "2.0.0-rc.4",
    "@angular/platform-browser": "2.0.0-rc.4",
    "@angular/platform-browser-dynamic": "2.0.0-rc.4",
    "@angular/router": "3.0.0-beta.1",
    "@angular/router-deprecated": "2.0.0-rc.2",
    "@angular/upgrade": "2.0.0-rc.4",

    "systemjs": "0.19.27",
    "core-js": "^2.4.0",
    "reflect-metadata": "^0.1.3",
    "rxjs": "5.0.0-beta.6",
    "zone.js": "^0.6.12",

    "lodash": "4.13.1",
    "angular2-in-memory-web-api": "0.0.14",
    "bootstrap": "^3.3.6"
  }

我在这里缺少什么胶水?

【问题讨论】:

  • 您是否还在任何组件上添加了HttpHTTP_PROVIDERSproviders: [...]?如果您这样做了,那么将使用这些提供程序。
  • 谢谢,这就是我的问题所在。我的主要应用程序组件的提供程序集合中有 HTTP_Providers。我删除了它,现在它正在使用我的实现。

标签: angular angular2-http


【解决方案1】:

确保您没有在某些组件上提供 HTTP_PROVIDERSHttp,否则可能会使用它来代替(取决于提供它的确切位置)。

【讨论】:

    【解决方案2】:

    这对我有用。我必须配置我的基本服务 url。当我在本地运行和部署到产品服务器时,它应该检测环境。

    @Injectable()
    export class HttpService extends Http {
    
      static SERVICE_BASE_URL = '';
    
      constructor(backend: XHRBackend, options: RequestOptions) {
        super(backend, options);
    
        if (/http:\/\/(localhost|127.0.0.1)/.test(window.location.href)) {
          HttpService.SERVICE_BASE_URL = 'http://localhost:8000';
        } else {
          HttpService.SERVICE_BASE_URL = 'http://mywebsite.com/api';
        }
      }
    
      get(url: string, options?: RequestOptionsArgs): Observable<Response> {
        return super.get(this.toTargetUrl(url), options);
      }
    
      post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response> {
        return super.post(this.toTargetUrl(url), body, options);
      }
    
      put(url: string, body: any, options?: RequestOptionsArgs): Observable<Response> {
        return super.put(this.toTargetUrl(url), body, options);
      }
    
      delete(url: string, options?: RequestOptionsArgs): Observable<Response> {
        return super.delete(this.toTargetUrl(url), options);
      }
    
      toTargetUrl(url: string): string {
        return url = /^https?:/.test(url) ? url : HttpService.SERVICE_BASE_URL + url;
      }
    }
    

    这就是我在app.module.ts中的配置方式

    providers: [
        {
            provide: Http,
            useFactory: HttpFactory,
            deps: [XHRBackend, RequestOptions]
        },
        UtilsProvider,
        LocalStorageProvider
    ]
    
    export function HttpFactory(backend: XHRBackend, options: RequestOptions) {
        return new HttpService(backend, options);
    }
    

    【讨论】:

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