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djangodjango-modelscruddjango-mptt

Django, how to do CRUD with django-mptt?


How we can implement CRUD functionality using generic views and django-mptt ?? I've searched a lot and couldn't find a single tutorial/sample code.

Let's say we have a Course hierarchy or Category hierarchy, or similar thing ... How we can Add/Delete/Update/Read them ??

For instance I have this model:

from django.db import models
from mptt.models import MPTTModel , TreeForeignKey


class Genre(MPTTModel):
    name            = models.CharField(max_length = 50 , unique = True)
    parent          = TreeForeignKey('self' , null = True , blank = True , related_name = 'children')

    class MPTTMeta:
        order_insertion_by = ['name']

and this views.py:

from django.views.generic.list_detail import object_list
from mp.models import Genre

def genres_list(request):
    ''' Shows all of the genres '''
    return object_list(request,
            queryset = Genre.tree.all() ,
            template_name = 'genres.html' ,
            # template_object_name = 'nodes' ## Adding "nodes" variable didn't solve the problem
    )

well ... I get this error (error is in line number "5" : {% recursetree nodes %}):

Caught VariableDoesNotExist while rendering: Failed lookup for key [nodes] in u"[{'paginator': None, 'is_paginated': False, 'page_obj': None, 'nodes_list': [<Genre: Genre object>, <Genre: Genre object>, <Genre: Genre object>, <Genre: Genre object>]}, {'csrf_token': <django.utils.functional.__proxy__ object at 0x7f5bb810f090>}, {'perms': <django.utils.functional.__proxy__ object at 0x7f5bb810ff10>, 'messages': <django.contrib.messages.storage.user_messages.LegacyFallbackStorage object at 0x324af50>, 'user': ....................................

    <html>
2   
3       {% load mptt_tags %}
4       <ul>
5           {% recursetree nodes %}
6           <li>
7               {{node.name}}

Solution

  • Simple CRUD application with MPTT models and class-based generic views (Django 1.4 The function-based implementation has been deprecated).

    Let's begin

    urls.py

    from django.conf.urls.defaults import patterns, include, url
    from django.views.generic import DetailView, ListView, CreateView, UpdateView
    from genre.models import Genre
    
    urlpatterns = patterns('',
        url(r'detail/(?P<pk>\d+)', DetailView.as_view(model=Genre), name="genre_detail",),
        url(r'update/(?P<pk>\d+)', UpdateView.as_view(model=Genre), name="genre_update",),
        url(r'create', CreateView.as_view(model=Genre), name="genre_create",),
        url(r'list', ListView.as_view(model=Genre), name="genre_list",),
    )
    

    models.py

    from django.core.urlresolvers import reverse
    from django.db import models
    from mptt.models import MPTTModel
    
    
    class Genre(MPTTModel):
        name = models.CharField(max_length=50 , unique=True)
        parent = models.ForeignKey('self' , null=True , blank=True , related_name='children')
    
        def get_absolute_url(self):
            return reverse('genre_detail', kwargs={'pk': self.pk, })
    
        class MPTTMeta:
            order_insertion_by = ['name']
    

    templates/genre_detail.html

    <html>
    <body>
    
    <div>Object: {{ object }}</div>
    <div>Object's name: {{ object.name }}</div>
    <div>Object's parent: {{ object.parent }}</div>
    
    </body>
    </html>
    

    templates/genre_form.html

    <html>
    <body>
    
    <form action="" method="post">
    {% csrf_token %}
    {{ form.as_ul }}
    
    <button>save</button>
    </form>
    </body>
    </html>
    

    templates/genre_list.html

    {% load mptt_tags %}
    <html>
    <body>
    <ul class="root">
        {% recursetree object_list %}
            <li>
                {{ node.name }}
                {% if not node.is_leaf_node %}
                    <ul class="children">
                        {{ children }}
                    </ul>
                {% endif %}
            </li>
        {% endrecursetree %}
    </ul>
    </body>
    </html>
    

    and that's it.

    I had some spare time today and shared this project on github https://github.com/kaygorodov/simple-crud-mptt.

    How can I define my own class-based view?

    genre/views.py

    from django.view.generic import UpdateView
    class MyCustomUpdateView(UpdateView):
        model = Genre
    
        def get_form_kwargs(self):
            """
            Returns the keyword arguments for instanciating the form.
            """
            kwargs = super(MyCustomUpdateView, self).get_form_kwargs()
            kwargs.update({'my_first_param_to_init_form': 1,
                          'my_second_param_to_init_form': 2,
            })
            return kwargs
    

    genre/urls.py

    url(r'update/(?P<pk>\d+)', MyCustomUpdateView.as_view(), name="genre_update",),