Pagination Django Class Based View Not Working Properly - django

Question

I'm trying to use Django (v2.0) pagination with CBV and got issues. The pagination is active because the tag {% if is_paginated %} returns "True" and shows the "PagNav" and the browser path changes too, like this (..?page=1, ...?page=2, etc...) but the displayed elements are all, not 3 just as I set in "paginate_by=3". For example, if the query has 15 elements must to show 3 elements per page and 1 to 5 in the pagination down bellow, but shows all elements. I attach an image and the code:
models.py:
from django.db import models
from django.contrib.auth.models import User
from ckeditor.fields import RichTextField
# Create your models here.
class Project(models.Model):
user = models.ForeignKey(User, on_delete = models.CASCADE, default=1)
name = models.CharField(verbose_name='Nombre del proyecto', max_length=200)
client = models.CharField(verbose_name='Nombre del cliente', max_length=200)
description = RichTextField(verbose_name='Descripción')
start = models.DateField(verbose_name='Fecha de Inicio', null=True, blank=True)
ending = models.DateField(verbose_name='Fecha de Finalización', null=True, blank=True)
order = models.SmallIntegerField(verbose_name="Orden", default=0)
created = models.DateTimeField(verbose_name='Fecha de creación', auto_now_add=True)
updated = models.DateTimeField(verbose_name='Fecha de modificación', auto_now=True)
class Meta:
verbose_name = 'Proyecto'
verbose_name_plural = 'Proyectos'
ordering = ['-start', 'order']
def __str__(self):
return self.name
class Album(models.Model):
project = models.ForeignKey(Project, verbose_name='Proyecto relacionado', on_delete = models.CASCADE)
title = models.CharField(verbose_name='Título de la imagen', max_length=200)
image = models.ImageField(verbose_name='Imagen', upload_to='portfolio')
created = models.DateTimeField(verbose_name='Fecha de creación', auto_now_add=True)
updated = models.DateTimeField(verbose_name='Fecha de modificación', auto_now=True)
class Meta:
verbose_name = 'Imagen en el album'
verbose_name_plural = 'Imágenes en el album'
ordering = ['created']
def __str__(self):
return self.title
views.py:
#method_decorator(staff_member_required(login_url='login'), name='dispatch')
class AlbumListView(SingleObjectMixin, ListView):
paginate_by = 3
template_name = "core/album_list_form.html"
def get(self, request, *args, **kwargs):
self.object = self.get_object(queryset=Project.objects.all())
return super().get(request, *args, **kwargs)
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['project'] = self.object
return context
def get_queryset(self):
return self.object.album_set.all()
#method_decorator(staff_member_required(login_url='login'), name='dispatch')
class ProjectUpdateView(UpdateView):
model = Project
template_name = "core/project_update_form.html"
form_class = ProjectUpdateForm
def get_success_url(self):
return reverse_lazy('portfolio_update', args=[self.object.id]) + '?ok'
urls.py:
from django.urls import path
from . import views
from .views import *
urlpatterns = [
path('', HomePageView.as_view(), name="home"),
path('album/list/<int:pk>', AlbumListView.as_view(), name="portfolio_list_album"),
# Update Views
path('project/update/<int:pk>', ProjectUpdateView.as_view(), name="portfolio_update"),
.
.
.
album_list_form.html:
{% extends "core/base.1.html" %}
{% load static %}
{% block title %}Imágenes de {{project.name}}{% endblock %}
{% block content %}
<div class="container">
<div class="row mt-5 mb-2 ml-1">
<div class="mt-3">
<h2 class="mt-5 mb-0"><a style="color: #343a40;" href="{% url 'portfolio_update' project.id %}">{{project.name}}</a></h2>
<div class="subheading mb-5">Imágenes:</div>
</div>
</div>
</div>
<div class="album py-5 bg-light">
<div class="container" style="margin-bottom: 2.5rem!important; margin-top: 2.5rem!important;">
<div class="row">
{% for album in project.album_set.all %}
<div class="col-md-4">
<div class="card mb-4 shadow-sm">
<img class="card-img-top border-bottom p-2 p-2 p-2 p-2 bg-light" src="{{album.image.url}}" alt="Card image cap">
<div class="card-body">
<p class="card-text" title="{{album.title}}" style="color: #343a40;"><strong>{{album.title|truncatechars:31}}</strong></p>
<div class="d-flex justify-content-between align-items-center">
<div class="btn-group">
<button type="button" class="btn btn-sm btn-outline-warning"><i class="fa fa fa-pencil"></i></button>
<button type="button" class="btn btn-sm btn-outline-danger"><i class="fa fa fa-times"></i></button>
</div>
<p></p>
</div>
<small class="text-muted">Última modificación: {{album.updated|date:"SHORT_DATE_FORMAT"}} {{album.updated|time:"h:i a"}}</small>
</div>
</div>
</div>
{% endfor %}
</div>
</div>
{% if is_paginated %}
<nav aria-label="Page navigation example">
<ul class="pagination pagination-lg justify-content-center">
{% if page_obj.has_previous %}
<li class="page-item">
<a class="page-link" style="color:#bd5d38;" href="?page={{ page_obj.previous_page_number }}" aria-label="Previous">
<span aria-hidden="true">«</span>
<span class="sr-only">Previous</span>
</a>
</li>
{% endif %}
{% for i in paginator.page_range %}
{% if page_obj.number == i %}
<li class="page-item"><a class="page-link" style="color:#ffffff; background-color: #343a40;" href="?page={{ i }}">{{ i }}</a></li>
{% else %}
<li class="page-item"><a class="page-link" style="color:#bd5d38;" href="?page={{ i }}">{{ i }}</a></li>
{% endif %}
{% endfor %}
{% if page_obj.has_next %}
<li class="page-item">
<a class="page-link" style="color:#bd5d38;" href="?page={{ page_obj.next_page_number }}" aria-label="Next">
<span aria-hidden="true">»</span>
<span class="sr-only">Next</span>
</a>
</li>
{% endif %}
</ul>
</nav>
{% endif %}
</div>
{% endblock %}

Answer 1

The core of the problem I think is that you write in the template:
{% for album in project.album_set.all %}
You thus make a project object. But regardless whether you paginate your class-based view, you will not paginate a related object manager. You only paginate the object_list.
Probably you can solve it with:
{% for album in object_list %}
Furthermore I think you make the class-based view extremely complicated: this is a class-based view over Albums. Yes, filtered albums, but so the Album should be central here. I think it can be rewritten to:
from django.urls import path
from . import views
from .views import *
urlpatterns = [
path('', HomePageView.as_view(), name="home"),
path('album/list/<int:project_pk>', AlbumListView.as_view(), name="portfolio_list_album"),
path('project/update/<int:pk>', ProjectUpdateView.as_view(), name="portfolio_update"),
]
Then in the view itself:
#method_decorator(staff_member_required(login_url='login'), name='dispatch')
class AlbumListView(ListView):
model = Album
paginate_by = 3
template_name = "core/album_list_form.html"
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['project'] = Project.objects.get(pk=self.kwargs['project_pk'])
return context
def get_queryset(self):
return Album.objects.filter(project_id=self.kwargs['project_pk'])