Enable submit button when all input fields are valid in Hyperscript?

Question

I'm playing around with htmx and hyperscript and I want the "submit button" (Add User) to be enabled when all required input fields are valid in a form. In this case, a non-empty name and a valid email address must have been defined.

<form hx-post="/example" hx-target="#table tbody" hx-swap="beforeend">
        <label class="control-label" for="nameInput">Name</label>
        <input id="nameInput" name="name" class="form-control" type="text" required placeholder="John Doe"/>
        
        <label class="control-label" for="emailInput">Email</label>
        <input id="emailInput" name="email" class="form-control" type="email" required placeholder="[email protected]"/>
        <button _="<what should I write here??>" class="btn btn-primary" disabled>Add User</button>
    </div>
</form>

What should I write instead of <what should I write here??> to make this happen?

Answer 1

Something like this should work:

<button _="on change from closest <form/>
             for elt in <[required]/>
               if the elt's value is empty
                 add @disabled then exit
               end
             end
             remove @disabled" class="btn btn-primary" disabled>Add User</button>

https://jsfiddle.net/xy8vn5jk/20/