title: How to do Angular2/4 validation with 3rd party JS components
body: <p>When it comes to Angular 2 validation, I saw different approaches. The basic is to use either HTML5 and template/model binding or forms with assigned validators. </p>
  
  <p>However when it comes to special rules it needs a lot of coding and with template binding (so no forms) mostly results in validation being scattered through HTML and TS code.</p>
  
  <p>Also another annoying thing around validation is that you need to alter validation rules in TS and also add extra HTML code to have those values on the page rendered (although this can be automated via directive)...</p>
  
  <p>Anyhow the ideal solution would be to use rules to model properties which then generates error messages to the controls. Similarly to .NET fluent validation and ModelState or in JS world similar to Aurelia.io validation: <a href="http://aurelia.io/docs/plugins/validation/" rel="nofollow noreferrer">http://aurelia.io/docs/plugins/validation/</a></p>
  
  <ol>
  <li>Is something similar possible in Angular2+?</li>
  <li>How/where to wire check  (based on model change) to a 3rd party (JS) library? Like fluent-ts-validator or flient-validator.</li>
  <li>How to set errors on controls, especially when we have f.e. controls inside<br>
  controls...</li>
  </ol>