FormView not saving data in Django

I am trying to allow users to save details of a workout for a specific exercise through submitting a form. My ExerciseDetailView displays the form how I'd like it to:

class ExerciseDetailView(DetailView):
    model = Exercise
    template_name = 'workouts/types.html'

    def get_context_data(self, **kwargs):
        context = super(ExerciseDetailView, self).get_context_data(**kwargs)
        context['form'] = WorkoutModelForm
        return context

But my problem is with saving the inputted data in the database. I have tried making both a FormView and a CreateView but am clearly missing something:

class ExerciseFormView(FormView):
    form_class = WorkoutModelForm
    success_url = 'workouts:exercise_detail'

    def form_valid(self, form):
        form.save()
        return super(ExerciseFormView, self).form_valid(form)

Here is my referenced WorkoutModelForm:

class WorkoutModelForm(forms.ModelForm):
    class Meta:
        model = Workout
        fields = ['weight', 'reps']

My template:

<form action="{% url 'workouts:workout' exercise.id %}" method="post">
    {% csrf_token %}
    {{ form }}
    <button type="submit">Save</button>
</form>

Urls:

path('exercise/<int:pk>/detail/', ExerciseDetailView.as_view(), name='exercise_detail'),
path('exercise/<int:pk>/detail/', ExerciseFormView.as_view(), name='workout'),

And for context here is my Workout model which contains a get_absolute_url method:

class Workout(models.Model):
    weight = models.FloatField(default=0)
    reps = models.PositiveIntegerField(default=0)
    created = models.DateField(auto_now_add=True)
    updated = models.DateField(auto_now=True)
    exercise = models.ForeignKey(Exercise, on_delete=models.CASCADE, default=None)

    def get_absolute_url(self):
        return reverse('exercise_detail', args=[str(self.pk)])

I am not receiving any errors, but when I submit the form my url remains the same, as I hoped, however the page just appears blank and the objects are not recorded. Can anybody please help me see what the problem is?

Solution

The problem is not your view, the Django logic will never trigger this view, the URLs are perfectly overlapping, so that means that for a URL, it will always trigger the first view (here the ExerciseDetailView), you should make the paths non-overlapping, for example with:

path('exercise/<int:pk>/detail/', ExerciseDetailView.as_view(), name='exercise_detail'),
path('exercise/<int:pk>/workout/', ExerciseFormView.as_view(), name='workout'),

Triggering the logic will however not be sufficient, since it will not link the Workout to the necessary exercise, you can alter the logic to:

from django.urls import reverse

class ExerciseFormView(CreateView):
    form_class = WorkoutModelForm

    def form_valid(self, form):
        form.instance.exercise_id = self.kwargs['pk']
        return super().form_valid(form)

    def get_success_url(self):
        return reverse('workouts:exercise_detail', kwargs={'pk': self.kwargs['pk']})