title: How to use custom validators of github.com/1000hz/bootstrap-validator
body: <p>From the documentation <a href="http://1000hz.github.io/bootstrap-validator/" rel="nofollow noreferrer">http://1000hz.github.io/bootstrap-validator/</a>:</p>
  
  <blockquote>
    <p>Add custom validators to be run. Validators should be functions that receive the jQuery element as an argument and return a truthy or falsy value based on the validity of the input.</p>
    
    <p>Object structure is: <code>{foo: function($el) { return true || false } }</code></p>
    
    <p>Adding the validator to an input is done just like the others, <code>data-foo="bar"</code>.</p>
    
    <p>You must also add default error messages for any custom validators via the errors option.</p>
  </blockquote>
  
  <p>I don't quite understand how to define my own custom validator and how to use it with this plugin.</p>
  
  <p>Could anyone give me a simple example or hint?</p>