The change of data in controller doesn't update automatically

Then I got some error messages:

ORIGINAL EXCEPTION: Component 'NewPostPage' must have either 'template', 'templateUrl', or '@View' set.
ORIGINAL STACKTRACE:
Error: Component 'NewPostPage' must have either 'template', 'templateUrl', or '@View' set.

In ionic 2, I only have @Page, any idea? My code:

import {Component} from 'angular2/core';

@Component({
  selector: 'pipes',
  changeDetection: 'ON_PUSH'
})

@Page({
  templateUrl: 'build/pages/post/new-post.html'
})