title: Angular 2 - Passing an argument to a custom pipe
body: <p>I have a created a pipe which can receive 2 arugments, but I'm not sure how I can sent them.</p>
  
  <p>here's my pipe:</p>
  
  <pre><code>export class TranslationPipe implements PipeTransform {
  
      private capitalize: boolean;
  
      constructor(
          private translationService: TranslationService
      ) {
          this.capitalize = true;
      }
  
      transform(key: string, capitalize?: boolean): string {
          if (typeof capitalize !== "undefined" || capitalize !== null)
              this.capitalize = capitalize;
  
          return this.translationService.getTranslation(key, this.capitalize);
      }
  }
  </code></pre>
  
  <p>and here is my HTML</p>
  
  <pre><code>{{ 'searchquery' | translate }}
  </code></pre>
  
  <p>this works, but how can I pass <code>capitlize = false</code> aswell? I've tried some googling but I can't really find any example the way I want to implement it (maybe I'm doing it wrong?)</p>
  
  <p>thanks for your help!</p>