update another table via form

Date: March 24th 2016
Last updated: March 24th 2016

The title is about the best I could come up with for this entry. This is the example: I have three models; 1) User, 2) Surfers and 3) Boards. Surfers can be considered a profile page for each surfer. I have a foreign key linking Surfer profiles to Users (OneToOne relationship), and Boards to Surfers (ManyToMany relationship). Any user can add a Board to the database. The objective of this example is to update a surfer profile with a new board if they are the currently logged in User.

views.py

@login_required
def addboard(request, surfer_id):
    """ Add a board to the website and associate with current profile """
    surfer = get_object_or_404(Surfer, pk=surfer_id)
    if request.method == "POST":
        form = BoardForm(request.POST)
        if form.is_valid():
            board = form.save()

            ############## solution ########################
            surfer.boards.add(board)
            surfer.save()
            ################################################
            return redirect('/{}/'.format(surfer_id))     
    else:
        form = BoardForm()

    # also return the surfer object so it is available in the html
    return render(request, 'surferprofile/addboard.html',
            {'surfer': surfer, 'form': form})

forms.py

class BoardForm(forms.ModelForm):
    class Meta:
        model = Board
        fields = ['boardtail','boardlength', 'boardwidth',
                    'boardthickness','boardvolume', 'boardrocker',
                    'boardmake', 'boardshaper']

addboard.html

{% extends 'surferprofile/base.html' %}
{% block title_block %} Add boards {% endblock %}

{% block body_block %}

    <h1>Add a new board</h1>

    <!-- check if the user id matches the surfer trying to be updated -->
    {% if user.id == surfer.user.id %}

        <form method="POST" class="post-form">
            {% csrf_token %}
            {{ form.as_p }}
            <button type="submit" class="save btn btn-default">Save</button>
        </form>

    {% else %}
        <!-- show the missmatch in IDs -->
        <p>user.id ={{ user.id}}</p>
        <p>surfer.user.id = {{ surfer.user.id}}</p>

    {% endif %}
{% endblock %}