p5.js functions not working on ajax success

I'm attempting to integrate a p5.js into a webpage that draws upon receipt of a successful response. I want to draw a tree based on a user entering information that becomes a certain node. I'm using Django as my backend.

views.py

def index(request):
    if request.method != 'POST':
        return render(request, 'index.html')
    else:
        if request.is_ajax():
            parent = request.POST.get('parent')
            child = request.POST.get('child')
            try:
            # various cases are run through...

                                    # case 7: neither child nor parent saved to tree -- 
                                    # create leaf from child and twig from parent
                                    twig = Twig.objects.create(text=parent)
                                    leaf = Leaf.objects.create(text=child)
                                    leaf.twigs.add(twig)
                                    data = {"twig_text" : twig.text,
                                            "twig_drawing" : twig.drawing,
                                            "twig_base_x" : 0,
                                            "twig_base_y" : 20,
                                            "twig_tip_x" : 20,
                                            "twig_tip_y" : 25,
                                            "leaf_text" : leaf.text,
                                            "leaf_drawing" : leaf.drawing,
                                            "leaf_base_x" : 20,
                                            "leaf_base_y" : 25,
                                            "leaf_tip_x" : 40,
                                            "leaf_tip_y" : 50,
                                    }
                                    twig.drawing = "filled"
                                    leaf.drawaing = "filled"
                                    return JsonResponse(data)
        else:        
            return render(request, 'index.html')

index.html

<html>
  <head>
  <script src="http://cdnjs.cloudflare.com/ajax/libs/p5.js/0.4.20/p5.js"></script>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
</head>
<body>
<div id="message" style="visibility: hidden;"></div>

<form method="POST">
  {% csrf_token %}
  <input type="text" id="txt" />
  <input type="submit" id="grow" value="grow" style="color: grey;"/>
</form>

<script>
  $("form").submit(function(e) {
    e.preventDefault();
    // ... 
    $.ajax({
      url : window.location.href,
      type : "POST",
      data : { csrfmiddlewaretoken : csrftoken,
               child : child,
               parent : parent,
             },
      success : function(json) {                  

                if (json["leaf_text"]){
              console.log(json['leaf_text'] + " was retrieved."); 

                function setup(){
                  }
                        function draw(){
              ellipse(random(20), random(50), random(10), random(20));
                  }
                }
              },
      error : function(xhr, errmsg, err) {
            console.log(xhr.status + ": " + xhr.responseText);
                                         },

         }); 
  });
</script>
</body>
</html>

My console test is successful. I can't figure out why the next few functions in 'success' aren't doing anything. I don't get any error messages in firebug. I'm new to p5, but I don't think that part of the code is the problem as I am this example: http://p5js.org/get-started/

Your root problem is that while the functions setup() and draw() are defined, they are never beeing called.

A more fundamental issue is that you are defining a function inside an if statement. While Javascript will allow this, it's pretty bad practice. What you'd normally do is define setup() and draw() at top or object levels, then call them when you need them.