Django: Adding variable to template context

Question

I have problem with a form if invalid data is submitted. My ErrorView view uses the app/feriehus_detail.html template, but I'm not including price_data in the template context.

This seems to cause a KeyError when the template tries to use price_data as an argument in a filter.

I can't figure out how to add it to the template context? Any help will be much appreciated.

I'm using Python 3.5 and Django 1.9.

Traceback:

Template error:
In template C:\Conference\app\templates\app\feriehus_detail.html, error at line 221
   Failed lookup for key [%s] in %r   211 :                             <td class="text-center">{{ object.price_rec_F }} kr</td>
   213 :                             <td class="text-center">{{ object.price_rec_F|percentage_dif:object.price_cur_F }}</td>
   214 :                         </tr>
   215 :                     </tbody>
   216 :                 </table>
   217 :             </div>
   218 :             <div class="col-xs-12" style="padding-bottom:25px;">
   219 :                 <div class="grid">
   220 :                     <div class="col-1-1">
   221 :                          {% column_chart price_data with height='500px' %} 
   222 :                     </div>
   223 :                 </div>
   224 :             </div>

template:

<form role="form" action="{% url 'error' pk=feriehus.id %}" method="post">
    {% csrf_token %}
    {{ form|crispy }}
    <button type="submit">Send</button>
</form>

forms.py:

class ErrorForm(forms.Form):
    content = forms.CharField(
        required=True,
        widget=forms.Textarea
    )

    def __init__(self, *args, **kwargs):
        super(ErrorForm, self).__init__(*args, **kwargs)
        self.fields['content'].label = "Beskriv fejl"
        self.helper = FormHelper()

urls.py:

url(r'^feriehus/(?P<pk>[0-9]+)/$', views.FeriehusDetail.as_view(), name='feriehus_detail'),
url(r'^feriehus/(?P<pk>[0-9]+)/error/$', views.ErrorView.as_view(), name='error'),

views.py:

class FeriehusDetail(DetailView, FormMixin):
    model = Feriehus
    form_class = ErrorForm

    def get_context_data(self, **kwargs):
        context = super(FeriehusDetail, self).get_context_data(**kwargs)
        context['price_data'] = CreateContext.price_time_serie(pk=self.kwargs['pk'])
        return context

class ErrorView(FormView):
    form_class = ErrorForm
    template_name = 'app/feriehus_detail.html'

    def get_success_url(self, **kwargs):
        return reverse_lazy('feriehus_detail', kwargs={'pk': self.kwargs['pk']})

    def get_context_data(self, **kwargs):
        context = super(ErrorView, self).get_context_data(**kwargs)
        context['object'] = get_object_or_404(Feriehus, pk=self.kwargs['pk'])
        context['feriehus'] = get_object_or_404(Feriehus, pk=self.kwargs['pk'])
        #context['price_data'] = get_object_or_404(CreateContext.price_time_serie(pk=self.kwargs['pk']))
        return context

    def form_valid(self, form, **kwargs):
        form_content = form.cleaned_data['content']

        template = get_template('error_template.txt')
        context = Context({
            'form_content': form_content
        })
        content = template.render(context)

        email = EmailMessage(
        'mail',
        content,
        'from@email.com' + '',
        ['to@email.com']
        )
        email.send()
        return super(FeedbackView, self).form_valid(form, **kwargs)

Output of CreateContext.price_time_serie(pk=self.kwargs['pk']):

[{'data': [('Week 49', 654645), ('Week 01', 554645)], 'name': 'Recommended price'}, {'data': [('Week 49', 3398), ('Week 01', 3398)], 'name': 'Current price'}]

Answer 1

As the comment above says, I dont know what CreateContext.price_time_serie() is supposed to do. Until you'll explain that we can only speculate what you are trying to achieve there.

If that is a way how to obtain the primary key for CreateContext record, then you have to add another parameter to the function, as get_object_or_404() expected at least two parameters - the first one is the model class you are trying to get, the others are parameters for the SQL query to identify the record to get. So I guess it should be something like this:

def get_context_data(self, *args, **kwargs):
    ...
    context['price_data'] = get_object_or_404(CreateContext, pk=CreateContext.price_time_serie(pk=self.kwargs['pk']))
    ...