Django Bogotá. CBV

Django Meetup Bogotá. Class Based Views with examples.
Source code: https://github.com/ctrl-alt-delete/cbvexamples

If you are looking for Django developer, contact me at http://vero4ka.info

Transcript

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

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2. View Slide

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

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4. CBV vs. FBV
   

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5. Classes
   View
   TemplateView
   RedirectView
   ListView CreateView
   UpdateView
   DetailView
   DeleteView
   

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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
   

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7. Models
   

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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
   

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9. URLs
   

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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/$', views.Noticias.as_view(), name="noticias"),
    # Update view
    url(r'^noticia/(?P\d+)/$', views.UpdateNoticia.as_view(), name="update_noticia"),
    # Create view
    url(r'^noticia/create/$', views.CreateNoticia.as_view(), name="create_noticia"),
    # Detail view
    url(r'^noticia/(?P\d+)/$', views.Noticia.as_view(), name="noticia"),
    # Delete view
    url(r'^noticia/delete/(?P\d+)/$', views.DeleteNoticia.as_view(), name="delete_noticia"),
    )
    URLs
    

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11. Views
    

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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 %}
    {{ noticia.title }}
    {% endfor %}
    {% endblock main_content %}
    ListView
    

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13. View Slide

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
    

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15. View Slide

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

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

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19. View Slide

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

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22. Form Views
    

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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
    

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24. Template:
    {% include "noticias/base.html" %}
    {% block main_content %}
    
    {% csrf_token %}
    
    {{ form }}
    
    
    
    Save
    
    
    
    
    {% endblock main_content %}
    FormView
    

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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
    

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27. View Slide

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
    

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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
    

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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\d+)/$', views.UpdateNoticia.as_view(), name="update_noticia"),
    UpdateView
    

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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:
    
    {% csrf_token %}
    
    >Cancel
    
    Yes, I'm sure
    
    
    
    
    DeleteView
    

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

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36. Mixin
    

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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
    

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38. View Slide

39. Decoradores
    

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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
    

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

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