title: How make multicolumns pipes filter?
body: <p>I have such a paipe and it will work only for the column: name a for the author no longer.</p>
  
  <p><pre>
  export class FilterBook2 implements PipeTransform {</p>
  
  <code>transform(items: Book[], filter: Book): any {
      if (!items || !filter) {
          return items;
      }
  
      // filter items array, items which match and return true will be kept, false will be filtered out
  
      return items.filter((item) =&gt; item.Nazwa.indexOf(filter.Nazwa) || item.Autor.indexOf(filter.Autor)  !== -1)
  
  }
  </code></pre>
  
  <p>}</p>
  
  <p>
  Input date:</p>
  
  <p>filterargs = { Nazwa: "", Autor: "" }</p>