title: How to disable a step in Angular Material Stepper?
body: <p>I have 3 steps in an Angular Material horizontal stepper.  I want to enable the first 2 by default but have the 3 step disabled (but not hidden).  </p>
  
  <p>These steps don't necessary have form values which decide if the current step is valid or not.  There are a series of backend calls that occur which decide if the current step is valid or not.  The linear mode option looks like it would work but it seems to rely on their being a form with required values in order to determine if the form is valid or not.  I don't have a form but still want the same type of functionality.  Any ideas?</p>
  
  <p><a href="https://stackblitz.com/angular/dqllekdmmly?file=app%2Fstepper-overview-example.ts" rel="nofollow noreferrer">https://stackblitz.com/angular/dqllekdmmly?file=app%2Fstepper-overview-example.ts</a></p>