init jquery ui widget on first click

datepicker.html

<input class="addDatepicker" name="date">

dialog.html

<span class="dialogControl" id="question" data-dialogTarget="#answer">?</span>

<div class="dialogContent" id="answer">
     <!-- dialog content here -->
</div>

widget_init.js

$(document).ready(function (){
     $('.addDatepicker').on('click', function () {
        // If we're not actually a datepicker yet, make us one.
        if ($(this).not(':data(datepicker)')) {
             $(this).datepicker({
                  // my datepicker options
             });
        }
     });
     $('.dialogControl').on('click', function () {
          var $target = $($(this).data('dialogTarget'));
          if ($target.length) {
               if ($target.not(':data(dialog)'))) {
                    $target.dialog({
                         // my dialog options
                    });
               }
               $target.dialog("open");
          }
     });
});