title: Pass class to children component host
body: <p>I'm used to React approach where I could basically inject anything anywhere.</p>
  
  <p>I have a dumb <code>Button</code> or <code>app-button</code> component in Angular. It's inline-block (<code>:host</code> class), so its width depends on the content. In this case, I can't override its params like <code>display: block</code> or set width. I can do it manually by adding new <code>@Input</code> per param (<code>[display]</code>, <code>[width]</code>) but it's not really nice.</p>
  
  <p>The behavior I want to have is an input/directive on this component to provide an explicitly inject class to the inside of the child component.</p>
  
  <p>In React I would just add prop with the class name and assign it or pass some inline styles, depending on what style system I'm using.</p>
  
  <p>Is there any way/lib/util to handle this problem?</p>