jQuery script works only once, then TypeError: $(…) is not a function

Question

I've downloaded this script for use conditional fields in forms:

(function ($) {
  $.fn.conditionize = function(options) {

    var settings = $.extend({
        hideJS: true
    }, options );

    $.fn.showOrHide = function(is_met, $section) {
      if (is_met) {
        $section.slideDown();
      }
      else {
        $section.slideUp();
        $section.find('select, input').each(function(){
            if ( ($(this).attr('type')=='radio') || ($(this).attr('type')=='checkbox') ) {
                $(this).prop('checked', false).trigger('change');
            }
            else{
                $(this).val('').trigger('change');
            }
        });
      }
    }

    return this.each( function() {
      var $section = $(this);
      var cond = $(this).data('condition');

      // First get all (distinct) used field/inputs
      var re = /(#?\w+)/ig;
      var match = re.exec(cond);
      var inputs = {}, e = "", name ="";
      while(match !== null) {
        name = match[1];
        e = (name.substring(0,1)=='#' ? name : "[name=" + name + "]");
        if ( $(e).length && ! (name in inputs) ) {
            inputs[name] = e;
        }
        match = re.exec(cond);
      }

      // Replace fields names/ids by $().val()
      for (name in inputs) {
        e = inputs[name];
        tmp_re = new RegExp("(" + name + ")\\b","g")
        if ( ($(e).attr('type')=='radio') || ($(e).attr('type')=='checkbox') ) {
          cond = cond.replace(tmp_re,"$('" + e + ":checked').val()");
        }
        else {
          cond = cond.replace(tmp_re,"$('" + e + "').val()");
        }
      }

      //Set up event listeners
      for (name in inputs) {
        $(inputs[name]).on('change', function() {
          $.fn.showOrHide(eval(cond), $section);
        });
      }

      //If setting was chosen, hide everything first...
      if (settings.hideJS) {
        $(this).hide();
      }
      //Show based on current value on page load
      $.fn.showOrHide(eval(cond), $section);
    });
  }
}(jQuery));

I'm trying this because I need to use conditionize() in one of my tabs and when I reload the tab, all works but if I go to other tab and I return to the previous tab(where I need this works), I get that error.

When I change tabs, I'm only reloading one part of the page.

When I load the page this works perfectly, but if I try to call function again from browser console, it tells me that TypeError: $(...)conditionize() is not a function .

I have included the script in header tag and I'm calling it with this script on the bottom of body:

<script type="text/javascript">
     $('.conditional').conditionize();
</script>

EDIT:

I have written

<script type="text/javascript">
    console.log($('.conditional').conditionize);
    setTimeout(function () {console.log($('.conditional').conditionize);}, 2);
</script>

and this print me at console the function, and when 2 milliseconds have passed, it print me undefined

Answer 1

I have found the solution.

Because any reason, the $ object and jQuery object are not the same in my code.

I have discovered it using this on browser console:

$===jQuery

This return false (This was produced because in other JS, I was using the noConflict() , which give me the problem)

Explanation: noConflict()

So I have solved it changing the last line of my JS by:

//Show based on current value on page load
      $.fn.showOrHide(eval(cond), $section);
    });
  }
}($));

Putting the $ instead of 'jQuery'