Django Meetup Bogotá. Class Based Views con ejemplos. Class Based Views with examples. Código fuente: https://bitbucket.org/vero4ka/cbvexamples Class Based Views with examles.

1. Class Based Views
RosBusinessConsulting
www.vero4ka.info
@vero4ka_ru

3. Class Based Views Inspector
http://ccbv.co.uk

4. CBV vs. FBV

5. Classes
View
TemplateView
RedirectView
ListView CreateView
UpdateView
DetailView
DeleteView

6. from django.views.generic import View
class MyViewClass(View):
def get(self, request, *args, **kwargs):
context = # calcular lo que usted desea pasar al template
return self.render_to_response(context)
def post(self, request, *args, **kwargs):
context = # calcular lo que usted desea pasar al template
return self.render_to_response(context)
View class

7. Models

8. class Rubrica(models.Model):
title = models.CharField(u'Título', max_length=255)
def __unicode__(self):
return unicode(self.title)
class Noticia(models.Model):
is_published = models.BooleanField(u'Status', default=False)
pub_date = models.DateTimeField(u'Fecha de publicación',
default=datetime.datetime.now)
author = models.ForeignKey(User, verbose_name=u"Autor")
rubric = models.ForeignKey(Rubrica, verbose_name=u"Rúbrica")
title = models.CharField(u'Título', max_length=500, default=u'')
body = models.TextField(u'Contenido')
def __unicode__(self):
return self.title
class Meta(object):
ordering = ['-pub_date']
Models

9. URLs

10. from django.conf.urls.defaults import patterns, url
from django.views.generic import TemplateView
from noticias import views
urlpatterns = patterns("",
# Index static page
url(r'^$|^index/$', TemplateView.as_view(template_name='noticias/index.html'), name="index"),
# List view
url(r'^noticias/$', views.Noticias.as_view(), name="noticias"),
# Update view
url(r'^noticia/(?P<pk>d+)/$', views.UpdateNoticia.as_view(), name="update_noticia"),
# Create view
url(r'^noticia/create/$', views.CreateNoticia.as_view(), name="create_noticia"),
# Detail view
url(r'^noticia/(?P<pk>d+)/$', views.Noticia.as_view(), name="noticia"),
# Delete view
url(r'^noticia/delete/(?P<pk>d+)/$', views.DeleteNoticia.as_view(), name="delete_noticia"),
)
URLs

11. Views

12. View:
from django.views.generic import ListView
from noticias.models import Noticia as NoticiasModel
class Noticias(ListView):
model = NoticiasModel
template_name = "noticias/list.html"
context_object_name = "noticias"
Template:
{% include "noticias/base.html" %}
{% block main_content %}
{% for noticia in noticias %}
<p>{{ noticia.title }}</p>
{% endfor %}
{% endblock main_content %}
ListView

14. class Noticias(ListView):
model = NoticiasModel
template_name = "noticias/list.html"
context_object_name = "noticias"
def get_context_data(self, **kwargs):
context = super(Noticias, self).get_context_data(**kwargs)
context.update(page_title='Lista de nuestras noticias')
return context
def get_queryset(self):
return super(NoticiasDeCine, self).get_queryset().filter(rubric__slug="cine")
ListView
añadir data
al contexto
modificar
queryset

16. View:
class Noticias(ListView):
model = NoticiasModel
context_object_name = "noticias"
paginate_by = 5
Template:
{% for noticia in noticias %}
<p>{{ noticia.title }}</p>
{% endfor %}
{% if paginator.num_pages > 1 %}
{% if page_obj.has_previous %}
<a href="?page={{ page_obj.previous_page_number }}">Anterior</a>
{% endif %}
<span>Pagina {{ page_obj.number }} de {{ page_obj.paginator.num_pages }}</span>
{% if page_obj.has_next %}
<a href="?page={{ page_obj.next_page_number }}">Siguiente</a>
{% endif %}
{% endif %}
ListView
paginación

18. View:
from django.views.generic import DetailView
class Noticia(DetailView):
model = NoticiasModel
template_name = "noticias/detail.html"
context_object_name = "noticia"
Template:
<p>{{ noticia.pub_date }}</p>
<p>{{ noticia.title }}</p>
<p>{{ noticia.rubric }}</p>
<p>{{ noticia.author }}</p>
<p>{{ noticia.body }}</p>
URLs:
url(r'^noticia/(?P<pk>d+)/$', views.Noticia.as_view(), name="noticia"),
DetailView
buscar un
objeto por pk

20. View:
from django.views.generic import DetailView
class Pubrica(DetailView):
model = RubricaModel
template_name = "noticias/rubrica.html"
slug_field = "slug"
Template:
<p>
<b>Title:</b> {{ object.title }}
</p>
<p>
<b>Slug:</b> {{ object.slug }}
</p>
URLs:
url(r'^rubrica/(?P<slug>w+)/$', views.Pubrica.as_view(), name="rubrica"),
DetailView
buscar un objeto
por slug

22. Form Views

23. Form:
from django import forms
class ContactenosForm(forms.Form):
email = forms.EmailField(label="Email")
name = forms.CharField(label="Nombre")
message = forms.CharField(label="Mensaje", widget=forms.Textarea())
View:
class Contactenos(FormView):
form_class = ContactenosForm
template_name = "noticias/contactenos.html"
success_url = reverse_lazy("gracias")
URLs:
url(r'^contactenos/$', views.Contactenos.as_view(), name="contactenos"),
url(r'^gracias/$', TemplateView.as_view(template_name='noticias/gracias.html'),
name="gracias"),
FormView

24. Template:
{% include "noticias/base.html" %}
{% block main_content %}
<div class="container">
<form method="post" action="">{% csrf_token %}
<div class="row">
<div class="span12">{{ form }}</div>
</div>
<div class="row">
<div class="span12">
<button type="submit" class="btn btn-success">Save</button>
</div>
</div>
</form>
</div>
{% endblock main_content %}
FormView

26. from django.shortcuts import redirect
class Contactenos(FormView):
form_class = ContactenosForm
template_name = "noticias/contactenos.html"
success_url = reverse_lazy("gracias")
def form_valid(self, form):
send_mail('Email de {0}'.format(form.cleaned_data["name"]),
form.cleaned_data["message"], form.cleaned_data["email"]
['example@'example.com], fail_silently=False)
return redirect(self.get_success_url())
FormView
enviar un correo cuando el
formulario es correcto

28. Otros metodos:
def form_invalid(self, form):
"""
Acciones a realizar si el formulario es incorrecto.
"""
return self.render_to_response(self.get_context_data(form=form))
def get_initial(self):
"""
Definir un diccionario que será utilizado para proveer los datos iniciales del formulario
"""
return self.initial.copy()
FormView

29. Form:
from django.forms import ModelForm
from noticias.models import Noticia
class NoticiaForm(ModelForm):
class Meta():
model = Noticia
exclude = ('pub_date',)
View:
from django.views.generic import CreateView
class CreateNoticia(CreateView):
model = NoticiasModel
template_name = "noticias/form.html"
form_class = NoticiaForm
success_url = reverse_lazy("noticias")
CreateView

31. View:
from django.views.generic import UpdateView
class UpdateNoticia(UpdateView):
model = NoticiasModel
template_name = "noticias/form.html"
form_class = NoticiaForm
success_url = reverse_lazy("noticias")
URLs:
url(r'^noticia/update/(?P<pk>d+)/$', views.UpdateNoticia.as_view(), name="update_noticia"),
UpdateView

33. View:
from django.views.generic import DeleteView
class DeleteNoticia(DeleteView):
model = NoticiasModel
success_url = reverse_lazy("noticias")
template_name = "noticias/delete_confirm.html"
Template:
<div class="container">
<form method="post" action="">{% csrf_token %}
<div class="row">
<div class="span3"><a href="{% url noticias %}" class="btn btn-danger"
>Cancel</a></div>
<div class="span3">
<button type="submit" class="btn btn-success">Yes, I'm sure</button>
</div>
</div>
</form>
</div>
DeleteView

35. Do one thing, and do it well
The UNIX philosophy

36. Mixin

37. import json
from django.http import HttpResponse
class JSONResponseMixin(object):
response_class = HttpResponse
def render_to_response(self, context, **response_kwargs):
response_kwargs['content_type'] = 'application/json'
return self.response_class(
self.convert_context_to_json(context),
**response_kwargs
)
def convert_context_to_json(self, context):
return json.dumps(context)
class NoticiasJSON(JSONResponseMixin, ListView):
model = NoticiasModel
Mixin

39. Decoradores

40. ● En URLs:
from django.contrib.auth.decorators import login_required as _lr
urlpatterns = patterns("",
url(r'^noticias/$', _lr(views.Noticias.as_view()), name="noticias"),
)
● En Views:
from django.contrib.auth.decorators import login_required
from django.views.utils.decorators import method_decorator
class Niticias(ListView):
@method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(Niticias, self).dispatch(*args, **kwargs)
Decoradores

41. Gracias por su atención!
Ejemplos:
https://bitbucket.org/vero4ka/cbvexamples