How do I set default Http Headers for all requests in Ionic 2?

Question

I've searched how to set up Default Http Headers all my request and I found how to implement in in Angular 2 with bootstrap function, but it's not available in Ionic 2, as described in this question How to set default HTTP header in Angular2?.

I want to set Content-Type header to application/json instead of setting it up in per-request

I have been trying to override BaseRequestOptions and injecting them in my App, but I cannot get to override them.

app.ts

...
import {BaseRequestOptions, Headers, HTTP_PROVIDERS, Http, RequestOptions} from '@angular/http';

@Injectable()
export class MyRequestOptions extends BaseRequestOptions{
    headers:Headers = new Headers({
        'Content-Type': 'application/json; charset=UTF-8'
    });
}

@App({
  template: '<ion-nav [root]="rootPage"></ion-nav>',
  config: {},
  providers: [HTTP_PROVIDERS, MyRequestOptions]
})
export class MyApp {
  rootPage: any = HomePage;

  constructor(platform: Platform) {
     // init
  }
}

myService.ts

import {Injectable} from '@angular/core';
import {Http, Headers} from '@angular/http';

@Injectable()
export class MyService {
    constructor(private http: Http) {
    }

    getUser(id) {
         return this.http.post('/api/User/Get/', JSON.stringify({ id: id }));
    }
}

There's something I'm missing, am I using wrong the providers injection?

Answer 1

You don't register MyRequestOptions properly:

import { provide } from '@angular/core';
import { HTTP_PROVIDERS, RequestOptions, BaseRequestOptions, Headers } from '@angular/http';

...
@App({
  template: '<ion-nav [root]="rootPage"></ion-nav>',
  config: {},
  providers: [HTTP_PROVIDERS, provide(RequestOptions, { useClass: MyRequestOptions })]
})

Or you can try to register provider via map literal like this:

{ provide: RequestOptions, useClass: MyRequestOptions }