How to write Angularjs directive attributes which have no RHS in hiccup?

I am writing an AngularJS app with markup in hiccup. The mark-up is something like this

<div modal-show modal-visible="showDialog" .........></div>

The corresponding Hiccup I have written is this:

[:div.modal.fade
  {  :modal-show 
     :modal-visible "showDialog"
     :aria-hidden "true",
     :aria-labelledby "terms-n-services-modal-label",
     :role "dialog",
     :tabindex "-1"}
    [:div.modal-dialog
     [:div.modal-content
      [:div.modal-header
       [:button.close
        {:aria-hidden "true", :data-dismiss "modal", :type "button"}
        "×"]
       [:h4#terms-n-services-modal-label.modal-title "Terms & Services "]]
      [:div.modal-body ""]
      [:div.modal-footer
       [:button.btn.btn-default
        {:data-dismiss "modal", :type "button"}
        "Close"]]]]]

Now I get this error when try running my code:

java.lang.RuntimeException: Map literal must contain an even number of forms, compiling

Now I know, the map literal will not be able to represent :modal-show because it doesn't have its value/RHS to make a pair.

What should I do ? just write an empty string or null ?

Solution

I think the best solution will be to set it on empty string. Result will be like modal-show="" but as far as I know it's gonna be interpreted in the same as just modal-show. If you want Hiccup to render just modal-show you probably need to dive into source, and add this function to it.

Check this out too: Are empty HTML5 data attributes valid?