没有Http的提供者

Question

I have issue with injecting HTTP into Angular 2 application. Few days ago it was working fine but now I have error:

ORIGINAL EXCEPTION: No provider for Http!

There is main.ts

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppModule } from './app.module';
import { LoginModule } from "./login/login.module";
import { Http } from "@angular/http";


platformBrowserDynamic().bootstrapModule(LoginModule);

Login module.ts

@NgModule({
    imports: [BrowserModule, FormsModule], // external modules for all components
    declarations: [LoginComponent], // component which belong to this module
    bootstrap: [LoginComponent] // component on load
})
export class LoginModule {
}

And finally LoginComponent in LoginModule

import { Component } from '@angular/core';
import { AccountService } from "../data/account.service";
import { Http, Response, RequestOptions, Headers } from '@angular/http';
import { LocalStorage } from '../storage/storage';

@Component({
    selector: 'tp-login',
    templateUrl: `app/login/login.html`,
    styleUrls: ['app/login/login.css'],
    providers: [AccountService, LocalStorage]

})

There is exception in LoginComponent about no HttpProvider. Somone know how to solve that issue ?

Answer 1

Good to incapsulate all your module dependencies into main class module inside @ngModule attribute

import { BrowserModule } from '@angular/platform-browser';
import {NgModule} from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    RouterModule.forRoot(appRoutes)
  ],
  providers: [],
  bootstrap: [AppComponent]
})

So you can be sure that when your module will be included as child dependency - all dependecies will be resolved before.

Answer 2

In the App Module.

Import HttpModule and Http from @angular/http :

import {HttpModule, RequestOptions, XHRBackend, Http} from "@angular/http";

Add the HttpModule to import property in @NgModule declarations:

imports: [
    HttpModule,
]

Provide Http in Providers property of @NgModule

providers: [
    {provide: Http, useFactory: (backend: XHRBackend, defaultOptions: RequestOptions) => new Http(backend, defaultOptions),rations
        deps: [XHRBackend, RequestOptions]}
],

Answer 3

First, remove the import { LoginModule } from "./login/login.module"; in your main.ts, it doesn't solve your problem.

Try importing HttpModule into your Login module file or in your root module:

 import { HttpModule } from '@angular/http'; @NgModule({ imports: [HttpModule, BrowserModule, FormsModule], declarations: [LoginComponent], // component which belong to this module bootstrap: [LoginComponent] // component on load }) export class LoginModule { } 

Answer 4

Add HttpModule in your component/ service file :

import { Http , HttpModule} from '@angular/http';

and then add it HttpModule in app.module.ts :

import { Http ,HttpModule} from '@angular/http';

and in ngModules imports also

imports: [
    BrowserModule,
    HttpModule   ]