title: Ionic Storage delivers undefined value
body: <p>How I can use the Ionic Storage within my application. I tried with the following, but when I try to read out I get always <code>[object Object]</code> as value back. It works when I have the get/set method in one class, but I want structure my project and outsource the storage part.</p>
  
  <pre><code>@Component({
        selector: 'page-login',
        templateUrl: 'login.html'
      })
      export class LoginPage {
  
        constructor(public testData: TestData) {}
  
        onLogin(form) { 
  
          if (form.valid) {
            this.testData.setTestParam("abc");
            console.log("Stored: " +   this.testData.getTestParam()) ;
            // delivers =&gt; Stored: [object Object]
          }
      }    
  </code></pre>
  
  <p><strong>TestData Class</strong></p>
  
  <pre><code>@Injectable()
  export class TestData {
  
   constructor(public storage : Storage) {}
  
   setTestParam(testparam) 
   {
     this.storage.set('test_param', testparam);
   }
  
   getTestParam(){
     return this.storage.get('test_param').then((value) =&gt; {
        return value;
     });
   }
  }
  </code></pre>