Chartjs-Django and Chart.js Not Rendering Graph Correctly

by

1👍

✅

Try this:

def get_context_data(self, **kwargs):
    context = super(ChartView, self).get_context_data(**kwargs)
    qs1 = Class.objects.filter(id__in=self.request.user.userprofile.class.all()).order_by('id')        
    class_names = [ cls.class_name for cls in qs1]
    books_count = [ Books.objects.filter(class=cls).count() for cls in qs1 ]
    context['qs1'] = class_names
    context['qs2'] = books_count
    return context

Here i want both the Class and Books queryset to be ordered by class because the order is crucial. Here in the context i inject the Class names and Books count directly in the context.

Use This srcipt in the template:

<script>
        var labels = "{{ qs1 }}";
        var ctx = document.getElementById("myChart");
        var myChart = new Chart(ctx, {
            type: 'bar',
            data: {
                labels: Array.from(labels),
                datasets: [{
                    label: "# of Books",
                     data: [{% for j in qs2 %}
                              {{ j }},
                            {% endfor %}],
                    backgroundColor: [
                        'rgba(255, 99, 132, 0.2)',
                        'rgba(255, 99, 132, 0.2)',
                        'rgba(54, 162, 235, 0.2)',
                        'rgba(255, 206, 86, 0.2)',
                        'rgba(75, 192, 192, 0.2)',
                        'rgba(153, 102, 255, 0.2)',
                        'rgba(255, 159, 64, 0.2)'
                    ],
                    borderColor: [
                        'rgba(255,99,132,1)',
                        'rgba(255,99,132,1)',
                        'rgba(54, 162, 235, 1)',
                        'rgba(255, 206, 86, 1)',
                        'rgba(75, 192, 192, 1)',
                        'rgba(153, 102, 255, 1)',
                        'rgba(255, 159, 64, 1)'
                    ],
                    borderWidth: 1
                }]
            }
        })
    },
    error: function(error_data){
        console.log("error")
        console.log(error_data)
    }
})
</script>

There is no need for ajax request you already got the data from the context

I hope this will work.

2👍

After working all day with Yusef BH, came to the following solution regarding rendering the data correctly. Of note is that the labels are still not coming through. I have opened up a separate SO issue for the labels. Here is the code that allowed me to display the items correctly on the graph.

My HTML

{% extends 'base5.html' %}

{% block body_block %}
<div class="box6">
          <h1 class="title">Number of Books By Author</h1>
<canvas id="myChart"></canvas>
<div>

  <script>
  var endpoint = '{% url "Books:chart_data" %}'
  var defaultData = [];
  var labels = [];
  array = {{ procedures3 }}
  $.ajax({
      method: "GET",
      credentials: 'same-origin',
      url: endpoint,
      success: function(data){
          defaultData = data.default
          var ctx = document.getElementById("myChart");
          var myChart = new Chart(ctx, {
              type: 'bar',
              data: {
                  labels: [{% for i in book %}{{ i.id }},{% endfor %}],
                  datasets: [{
                      label: "# of Procedures",
                      data: [{% for j in book_count %}
                               {{ j }},
                             {% endfor %}],
                      backgroundColor: [
                          'rgba(255, 99, 132, 0.2)',
                          'rgba(255, 99, 132, 0.2)',
                          'rgba(54, 162, 235, 0.2)',
                          'rgba(255, 206, 86, 0.2)',
                          'rgba(75, 192, 192, 0.2)',
                          'rgba(153, 102, 255, 0.2)',
                          'rgba(255, 159, 64, 0.2)'
                      ],
                      borderColor: [
                          'rgba(255,99,132,1)',
                          'rgba(255,99,132,1)',
                          'rgba(54, 162, 235, 1)',
                          'rgba(255, 206, 86, 1)',
                          'rgba(75, 192, 192, 1)',
                          'rgba(153, 102, 255, 1)',
                          'rgba(255, 159, 64, 1)'
                      ],
                      borderWidth: 1
                  }]
              }
          })
      },
      error: function(error_data){
          console.log("error")
          console.log(error_data)
      },
  })
  </script>
  {% endblock %}

Views.py

ChartView

class ChartData(LoginRequiredMixin,APIView):
    model = Author
    authentication_classes = (SessionAuthentication, BasicAuthentication)
    permission_classes = (IsAuthenticated,)

    def get(self, request, format=None):
        default_items = []
        labels = []
        data = {
            "labels": labels,
            "default": default_items,
        }
        return Response(data)

The ChartView

class ChartView(LoginRequiredMixin, TemplateView): template_name = 'Book/chart.html'

def get_context_data(self, **kwargs):
    context = super(ChartView, self).get_context_data(**kwargs)
    book = Author.objects.filter(id__in=self.request.user.userprofile.author.all()).order_by('id')
    books_count = [ Book.objects.filter(author=cls).count() for cls in book ]
    context['book'] = book
    context['book_count'] = books_count
    return context

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