title: Trouble with Observable and http json Angular
body: <p>I have a problem because I never draw the variable "datos" in the * nFor,
  I think the problem is in the render, 
  for this reason implements "Observable", however it still does not work</p>
  
  <p>Thanks for help!</p>
  
  <p>"header-menu.component.ts"</p>
  
  <pre><code>import { Component, Input, OnInit, ChangeDetectionStrategy } from '@angular/core';
      import { Http } from '@angular/http';
      import 'rxjs/add/operator/map';
      import 'rxjs/add/operator/catch';
      import { Observable } from 'rxjs/Observable';
  
      @Component({
          moduleId: module.id,
          selector: 'as-headermenu',
          templateUrl: 'header-menu.html',
          changeDetection: ChangeDetectionStrategy.OnPush
      })
  
      export class HeaderMenuComponent implements OnInit {
      datos = []; // Aqui se carga el json
      private ruta = 'assets/json_header_menu.json';  
  
      constructor(private http: Http) {}
  
      ngOnInit() {
           this.loadJson().subscribe(
                      vdatos =&gt; this.datos = vdatos,
                      err =&gt; console.log(err),
          () =&gt; console.log(this.datos));
          console.log(this.datos);
      }
  
  loadJson(): Observable&lt;any[]&gt; {
            return this.http.get(this.ruta)
              .map(res =&gt; res.json());
  }
  }
  </code></pre>
  
  <p>"header-menu.html"</p>
  
  <pre><code>&lt;ul *ngIf="datos"&gt; &lt;li *ngFor="let dato of datos | async; let i =
  index"&gt; {{ dato.url }} {{ dato.icono }} {{ dato.titulo }} {{ i }} 
  &lt;/li&gt; 
  </code></pre>
  
  <p></p>
  
  <p>"header-menu-module.ts"</p>
  
  <pre><code>import { NgModule } from '@angular/core';
  import { RouterModule } from '@angular/router';
  import { BrowserModule } from '@angular/platform-browser';
  import { HttpModule } from '@angular/http';
  
  import { HeaderMenuComponent } from './index';
  
  @NgModule({
      declarations: [
          HeaderMenuComponent
      ],
      imports: [
          RouterModule,
          BrowserModule,
          HttpModule
      ],
      exports: [
          HeaderMenuComponent
      ]
  })
  export class HeaderMenuModule {
  }
  </code></pre>
  
  <p>Image Console error:<a href="https://i.stack.imgur.com/n2R9R.png" rel="nofollow noreferrer">Console Error</a></p>