Testing the context
With no value, the attribute tests whatever the element is scoped to. Useful when a whole block depends on an
object existing at all, rather than on one property inside it.
<div b-context="order.customer" b-has-value>
<h3 b-value="name"></h3>
<p b-value="email"></p>
</div>
Empty string, null and undefined all count as no value.