Angular2 + Parent http Service + child @input

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular2 playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <app-parent>
    loading...
  </app-parent>
  </body>

</html>

/* Styles go here */

### Angular Starter Plunker - Typescript

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    
    '@angular/core': 'npm:@angular/core/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
    
    'rxjs': 'npm:rxjs@5.0.1',
    'typescript': 'npm:typescript@2.0.2/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app';

platformBrowserDynamic().bootstrapModule(AppModule)

//our root app component
import {Component, NgModule, Input, OnInit, OnChanges} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'

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

import {ApiService} from './parameter.service';

import 'rxjs/Rx';

@Component({
  selector: 'app-parent',
  template: `
  <h1>Parent</h1>
  <pre>
  {{ parameter | json }}
  </pre>
  <app-child [parameter]="parameter"></app-child>
  `
})
export class ParentComponent implements OnInit {
    parameter : any;
    
    constructor(private apiService: ApiService) {
      
    }
    
    ngOnInit() {
      this.apiService.fetch('users').subscribe(results => { this.parameter = results });
    }
}

@Component({
  selector: 'app-child',
  template: `
  <h1>Child</h1>
  <pre>
  {{ parameter | json }}
  </pre>
  `
})
export class ChildComponent implements OnInit, OnChanges {
    @Input() parameter : any ; 
    constructor() {
        console.log("constructor", this.parameter); // prints undefined
    }
    ngOnInit() {
        console.log("ngOnInit", this.parameter); // prints [1 ,2, 3]
    }
    
    ngOnChanges(changes) {
        console.log("ngOnChanges", this.parameter);
    }
}


@NgModule({
  imports: [ BrowserModule, HttpModule ],
  declarations: [ ParentComponent, ChildComponent ],
  providers: [ ApiService ],
  bootstrap: [ ParentComponent ]
})
export class AppModule {}

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

@Injectable()
export class ApiService {
  
  constructor(private http: Http) {}
  
  fetch(term: string) {
    return this.http.get('https://jsonplaceholder.typicode.com/' + term).map((response) => response.json())
  }
}