title: Value property on input element only updates once
body: <p>When I enter any number larger than 1 into the input element -- input value changes to 1 (because of the validation). For some reason, this works only for the first number I enter. If I, for example, enter 11, input value changes to 11, but it should change to 1. At least that's how I remember it worked in Angular 1. Any idea what's happening?</p>
  
  <pre class="lang-ts prettyprint-override"><code>import { Component } from '@angular/core';
  @Component({
    template:`
    &lt;input 
       type="number"
       (input)="validate($event.target.value)" 
       [value]="duration"&gt;
    &lt;p&gt;{{duration}}&lt;/p&gt;`
  })
  export class OneComponent{
    duration: number;
    constructor(){
      this.duration = 0;
    }
    validate(value){
      if(value &gt; 1) {
        this.duration = 1;
      }
      else {
        this.duration = value;
      }
    }
  }
  </code></pre>
  
  <p>Here's <a href="https://embed.plnkr.co/0clelaU5UitDR3gEyJJX/" rel="nofollow noreferrer">plunker</a> (one.component.ts)</p>