atril

class.*

Used as class.X, this adds class X when the expression is truthy and removes it when the expression evaluates to falsy.

Example:

<div let.checked="true">
  <label class.info="checked" class.error="!checked">
    <input twoway.checked="checked" type="checkbox">
    <span>I'm checked: {{checked}}</span>
  </label>
</div>