Navigation between pages inheriting the same class breaks ngFor?

[sphaso]

Short description of the problem:

The set up:

• I have two pages, each one has an ngFor with a simple pipe over a collection of (differently) typed items
• I have an @Injectable () class with some protected fields and methods. The two pages inherit this class

The problem:

• when I go from the first page to the second, I get an error on the console saying that there's no differ for the type of the first page

The debug:

• I tried debugging and I see that before going to the second page, the pipe gets called
• it seems that the return of the pipe is getting evaluated on the second page, and that's why it breaks (removing the pipe in the second template doesn't solve the issue)

If I remove the inheritance from the second page, of course, everything works just fine.

What behavior are you expecting?

Either the pipe transform doesn't get hit, or it doesn't throw an exception.

Steps to reproduce:
Is there a plnkr where I could try to reproduce this?

// master page
 @Injectable ()
 export class MasterPage {

     protected ToRevert : number[] = [];

     onPageDidEnter () {
         this.ToRevert = [];
     }
 }

//a snippet from the template. As you can see the call to the second page is inside an item of a list, is this why the pipe gets called?

 <ion-item *ngFor="#item of Dn | userFilter:inputFilter.value:onlySel:'descrizione'; #i = index"
                           [ngClass]="{green: item.selected}">
                     <ion-row>
                         <ion-col (click)="toggle(item, i)">
                             <span>{{item.descrizione}}</span>
                             <p>Editori: {{item.countEditori}}</p>
                         </ion-col>
                         <ion-col>
                             <a href="#" (click)="gotoEditori(item)"><ion-icon style="float:right;" name="ios-arrow-forward"></ion-icon></a>
                         </ion-col>
                     </ion-row>
                 </ion-item>
             </ion-list>

//the pipe
 @Pipe({
     name: 'userFilter'
 })
 export class UserFilterPipe implements PipeTransform {
     transform(value:any, args:string[]): any {
         let filter = args[0].toLocaleLowerCase();
         let field = args[2];
         let current = (filter && value) ? value.filter(ff => ff[field].toLocaleLowerCase().indexOf(filter) != -1) : value;
         if(args[1]){
             return current.filter(ff => ff.selected);
         }
         return current;
     }
 }

Ionic Version: 2.x

Browser & Operating System: iOS / Android / Chrome

Run ionic info from terminal/cmd prompt:

Cordova CLI: 4.2.0
Gulp version:  CLI version 3.9.1
Gulp local:   Local version 3.9.1
Ionic CLI Version: 2.0.0-beta.17
Ionic App Lib Version: 2.0.0-beta.8
OS: Windows 7 SP1
Node Version: v4.1.2

[sphaso]

Turns out that removing @Injectable () from the parent class resolves the issue without breaking inheritance, it was stupid of me to use that annotation in the first place. Sorry. Closing this.