How to make a simple JSONP asynchronous request in Angular 2?
Solution 1:
In the latest version of Angular
-
Import HttpClientModule and HttpClientJsonpModule modules in your app module's definition file
import { HttpClientModule, HttpClientJsonpModule } from '@angular/common/http'; @NgModule({ declarations: [ //... List of components that you need. ], imports: [ HttpClientModule, HttpClientJsonpModule, //... ], providers: [ //... ], bootstrap: [AppComponent] })
-
Inject http and map rxjs operator into your service:
import {Injectable} from '@angular/core'; import {HttpClient} from '@angular/http'; import 'rxjs/add/operator/map'; @Injectable() export class MegaSuperService { constructor(private _http: HttpClient) {} }
-
Make JSONP requests in the following way:
// inside your service this._http.jsonp('/api/get', 'callback').map(data => { // Do stuff. });
In Angular version 2 - version 4.3
-
Import JSONP module in your app module's definition file:
import {JsonpModule} from '@angular/http'; @NgModule({ declarations: [ //... List of components that you need. ], imports: [ JsonpModule, //... ], providers: [ //... ], bootstrap: [AppComponent] })
-
Inject jsonp service and map rxjs operator into your service:
import {Injectable} from '@angular/core'; import {Jsonp} from '@angular/http'; import 'rxjs/add/operator/map'; @Injectable() export class MegaSuperService { constructor(private _jsonp: Jsonp) {} }
-
Make requests using "JSONP_CALLBACK" as a callback property:
// inside your service this._jsonp.get('/api/get?callback=JSONP_CALLBACK').map(data => { // Do stuff. });
Solution 2:
In Angular 4.3 and up you should use HttpClientModule because the JsonpModule is deprecated.
- Import HttpClientModule and HttpClientJsonpModule into your module.
- Inject HttpClient into your service.
- Pass the callback key as the second argument for the
jsonp
method.
app.module.ts
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
// Import relevant http modules
import { HttpClientModule, HttpClientJsonpModule } from '@angular/common/http';
import { AppComponent } from './app.component';
import { ExampleService } from './example.service';
@NgModule({
declarations: [
AppComponent
],
imports: [
BrowserModule,
// Import relevant http modules
HttpClientModule,
HttpClientJsonpModule
],
providers: [ExampleService],
bootstrap: [AppComponent]
})
export class AppModule { }
example.service.ts
import { Injectable } from '@angular/core';
// Import HttpClient class
import { HttpClient } from '@angular/common/http';
@Injectable()
export class ExampleService {
// Inject HttpClient class
constructor(private http: HttpClient) { }
getData() {
const url = "https://archive.org/index.php?output=json&callback=archive";
// Pass the key for your callback (in this case 'callback')
// as the second argument to the jsonp method
return this.http.jsonp(url, 'callback');
}
}
Solution 3:
If this endpoint is jsonp-compliant, you can use the following. You need to find out the parameter to use to provide the jsonp callback. In the code below, I call it c
.
After having registered JSONP_PROVIDERS
when calling the bootstrap
function:
import {bootstrap} from 'angular2/platform/browser'
import {JSONP_PROVIDERS} from 'angular2/http'
import {AppComponent} from './app.component'
bootstrap(AppComponent, [ JSONP_PROVIDERS ]);
You can then execute your request using an instance of the Jsonp
class you injected from constructor:
import {Component} from 'angular2/core';
import {Jsonp} from 'angular2/http';
@Component({
selector: 'my-app',
template: `
<div>
Result: {{result | json}}
</div>
`
})
export class AppComponent {
constructor(jsonp:Jsonp) {
var url = 'https://accounts.google.com/logout&c=JSONP_CALLBACK';
jsonp.request(url, { method: 'Get' })
.subscribe((res) => {
(...)
});
}
}
See this question for more details:
- I need to do a http request to a mail chimp subscription list via a component post