Develop Reference

how to use class based views for a single page blog with pagination in django

this is the error messag am getting in a picture someone should please help me solve this problem i have been on it for the past 3days,
i have a single blog which is handled by multiple author or admin,so i decided to use class based views and when i create a new post gives an error saying i need blog_detail.html,since i dont have detail blog so i created a Detailview then adding my template_name = 'mymainblogpage.html' so once i create new post it will get posted but wont show the post but will only show the pagination,besides i cant search by post id for example http://127.0.0.1:8000/pages/blog/49/ i just get nothing here is my code.
views.py
def blog(request):
blog_post = Blog.objects.all()
ordering = ['-timestamp']
paginator = Paginator(blog_post, 2)
page_request_var = 'page'
page = request.GET.get(page_request_var)
try:
paginated_queryset = paginator.page(page)
except PageNotAnInteger:
paginated_queryset = paginator.page(2)
except EmptyPage:
paginated_queryset = paginator.page(paginator.num_pages)
context = {
'queryset': paginated_queryset,
'page_request_var': page_request_var
}
return render(request, 'pages/blog.html', context)
class BlogDetailView(DetailView):
model = Blog
template_name = 'pages/blog.html'
context_object_name = 'blog'
urls.py
path('blog/', BlogDetailView.as_view(), name='blog'),
path('blog/<int:pk>/', BlogDetailView.as_view(), name='blog-detail'),
models.py
def get_absolute_url(self):
return reverse('blog-detail', kwargs={'pk': self.pk})
blog.html
<br><p></p>
<section class="ftco-section bg-light" id="blog-section">
<div class="container">
<div class="row justify-content-center mb-5 pb-5">
<div class="col-md-10 heading-section text-center ftco-animate">
<h2 class="mb-4">Gets Every Single Updates Here</h2>
<p>Far far away, behind the word mountains, far from the countries Vokalia and Consonantia</p>
</div>
</div>
<div class="container">
<div class="row justify-content-center mb-5 pb-5">
<div class="col-lg-8 ftco-animate">
{% for blog in queryset %}
<h2 class="text-center">{{ blog.title }}</h2>
<div class="meta mb-3 text-center">
<div><h6><span><a href = "">written By {{ blog.user }}</span><small class="date"><i class="icon-clock"></i> {{ blog.timestamp|timesince }} ago</small><a/></h6>
</div>
</div>
<div><small class="icon-eye text-danger">{{ blog.view_count }}</small></div>
<div class="meta mb-3 text-center">
<h5>{% for cat in blog.categories.all %}<span class="btn btn-dark">{{ cat }}</span> {% endfor %}</h5>
</div>
<p class="text-center">{{ blog.overview }}</p>
{% endfor %}
<nav aria-label="pagination">
<ul class="pagination pagination-circle pg-blue">
{% if queryset.has_previous %}
<li class="page-item">Previous</li>
{% endif %}
<li class="page-item active">{{ queryset.number }}</li>
</a>
</li>
{% if queryset.has_next %}
<li class="page-item">Next</li>
{% endif %}
</ul>
</nav>
{% if is_paginated %}
<nav aria-label="pagination">
<ul class="pagination pagination-circle pg-blue">
{% if queryset.has_previous %}
<li class="page-item">Previous</li>
{% endif %}
<li class="page-item active">{{ queryset.number }}</li>
</a>
</li>
{% if queryset.has_next %}
<li class="page-item">Next</li>
{% endif %}
</ul>
</nav>
{% endif %}
</div>
</div>
</div>
</div>
</section>

You pagination isn't showing because you are passing context variable 'page_request_var': page_request_var instead of 'page_request_var': page
so change it because page_request_var is just a string 'page'.
If you need to use class-based list view then
from django.views.generic import ListView
class PostListView(ListView):
queryset = Post.published.all()
context_object_name = 'posts' # by default class list view uses object_list.
paginate_by = 2 # number of objects/posts per page
template_name = 'pages/blog.html' # by default uses <appname>/<modelname>_<view_type>.html
also, I would recommend using different templates for list and detail views because you are just searching the same template using so I think that may be a problem.

django bootstrap navbar dropdown elements not coming on other url while using same base.html

I am new to django and creating one app. I have create two mode on is master and other is details.
While using a bootstrap nav bar drop down on a single base.html i am able to get master records in drop down while i switch to different page when clicked any drop down element i didn't get drop down element. I am extending base.html in both the master as well as detail page. Please help with any option
dropdown working
http://127.0.0.1:8000/environment/
dropdown not working
http://127.0.0.1:8000/environment/env_name
base.html
<!-- menu buttons -->
<div class="collapse navbar-collapse" id="topNavBar">
<ul class="nav navbar-nav">
<li class="active">
<li class="nav-item dropdown" >
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="glyphicon glyphicon-globe" aria-hidden="true"></span> Environment
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
{% for envmaster in all_envmaster %}
<a class="dropdown-item" href="{% url 'environment:detail' envmaster.env_name %}">{{ envmaster.env_name }}</a>
<div class="dropdown-divider"></div>
{% endfor %}
</div>
<!--<a href="{% url 'environment:index' %}">
<span class="glyphicon glyphicon-globe" aria-hidden="true"></span> Environment
</a>-->
</li>
</li>
<li class="">
<a href="#">
<span class="glyphicon glyphicon-file" aria-hidden="true"></span> Details
</a>
</li>
</ul>
detail.html
<!-- Loads the path to your static files -->
{% extends 'environment/base.html' %}
{% block title %}Environment Details{% endblock %}
{% block body %}
<!--<img src="{{ envmaster.env_name }}" style="width: 250px;"><br>-->
<h3>{{ envmaster.env_name }}</h3>
{% if error_message %}
<p><strong>{{ error_message }}</strong></p>
{% endif %}
{% csrf_token %}
{% for envdetail in envmaster.envdetail_set.all %}
<li>{{ envdetail.env_component }} - {{ envdetail.component_class }} - {{ envdetail.value_1 }}</li><br>
{% endfor %}
{% endblock %}
index.html
<!-- Loads the path to your static files -->
{% extends 'environment/base.html' %}
{% block title %}Environment Details{% endblock %}
{% block body %}
{% if all_envmaster %}
<h3>Here are all Environment:</h3>
<ul>
{% for envmaster in all_envmaster %}
<li>{{ envmaster.env_name }}</li>
{% endfor %}
</ul>
{% else %}
<h3>You don't have any Environment</h3>
{% endif %}
{% endblock %}
models.py
from django.db import models
from django.urls import reverse
class Envmaster(models.Model):
env_name = models.CharField(primary_key=True, max_length=256)
env_type = models.CharField(max_length=256, blank=True, null=True)
env_owner = models.CharField(max_length=256, blank=True, null=True)
cur_release = models.CharField(max_length=256, blank=True, null=True)
class Meta:
db_table = 'ENVMASTER'
def get_absolute_url(self):
return reverse('environment:detail', kwargs={'pk': self.pk})
def __str__(self):
return self.env_name
class Envdetail(models.Model):
env_name = models.ForeignKey(Envmaster,on_delete=models.CASCADE)
env_component = models.CharField(max_length=256, blank=True, null=True)
component_class = models.CharField(max_length=256, blank=True, null=True)
value_1 = models.CharField(max_length=256, blank=True, null=True)
value_2 = models.CharField(max_length=256, blank=True, null=True)
value_3 = models.CharField(max_length=256, blank=True, null=True)
additional_info = models.CharField(max_length=256, blank=True, null=True)
class Meta:
db_table = 'ENVDETAIL'
def __str__(self):
return self.env_component
views.py
from django.views import generic
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.urls import reverse_lazy
from django.shortcuts import render, get_object_or_404
from .models import Envmaster
class IndexView(generic.ListView):
template_name = 'environment/index.html'
context_object_name = 'all_envmaster'
def get_queryset(self):
return Envmaster.objects.all()
class DetailView(generic.DetailView):
model = Envmaster
template_name = 'environment/detail.html'
url.py
urlpatterns = [
re_path(r'^$', views.IndexView.as_view(), name="index"),
#/environment/env_name/
re_path(r'^(?P<pk>[\w\-]+)/$', views.DetailView.as_view(), name='detail'),

You need to create a templates folder inside src folder you created and add create base.html inside that folder.
Than add in in you setting.py inside [Templates] add the location of the templates folder like this
'DIRS': [os.path.join(BASE_DIR, 'templates')],
and than just extend you html file
{% extends 'base.html' %}

While going through different posts and trying I have created a context file at app level so that once the class object is initialized it should retain the values within the navigation bar
from .models import Envmaster
def show_env_menu(context):
env_menu = Envmaster.onjects.all()
return {'env_menu': env_menu}

Not being able to display comments in template

I'm making a Post and Comment model by taking reference from internet. i created and Post and Comment model and it looks ok in django admin panel. i can add post and also a comment to any particular post. but getting trouble when I'm trying to display the comment under the post in templates(under post detail views). PLEASE HELP
models.py
class Post(models.Model):
author = models.ForeignKey(User,on_delete=models.CASCADE)
title = models.CharField(max_length=100)
content = RichTextField()
tags = models.CharField(max_length=50,blank=True,null=True)
date_posted = models.DateTimeField(default=timezone.now)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('post-detail',kwargs={'pk':self.pk})
class Comment(models.Model):
post = models.ForeignKey(Post,on_delete=models.CASCADE)
author = models.ForeignKey(User,max_length=50,on_delete=models.CASCADE)
text = models.TextField()
create_date = models.DateTimeField(default=timezone.now)
def get_absolute_url(self):
return reverse('discuss')
views.py
class PostDetailView(DetailView):
model = Post
def add_comment_to_post(request,pk):
return get_object_or_404(Post,pk=pk)
if request.method == "POST":
form = CommentForm(request.POST)
if form.is_valid():
comment = form.save(commit=False)
comment.post= post
comment.save()
return redirect('post-detail',pk=post.pk)
else:
form = CommentForm()
return render(request, 'discuss/comment_form.html',{'form':form})
def comment_remove(request,pk):
comment = get_object_or_404(Comment,pk=pk)
post_pk = comment.post.pk
comment.delete()
return redirect('post-detail', pk=post_pk)
post_detail.html
{% extends 'index.html' %}
{% block content %}
<article class="media content-section">
<div class="medaia-body">
<img class="rounded-circle article-img" src="{{ object.author.profile.image.url }}" alt="image not found">
<div class="article-metedata">
<a class="mr-2" href="{% url 'user-posts' object.author.username %}">{{object.author}}</a>
<small class="text-muted">{{ object.date_posted|date:"F d, Y"}}</small>
</div>
<h2 class="article-title">{{ object.title }}</h2>
<img class="query-img" src="{{ object.image.url }}" alt="image not found">
<p class="article-content">{{ object.content|safe }}</p>
</div>
</article>
{% if object.author == user %}
<div class="post-update-delete">
<button class="btn btn-outline-primary">Edit Post</button>
<button class="btn btn-outline-primary">Delete Post</button>
</div>
{% endif %}
<hr>
<a class="btn btn-primary btn-comment" href="{% url 'add_comment_to_post' pk=post.pk %}">Add Comment</a>
<!-- ############################### ABOVE CODE IS WORKING ############################# -->
<!-- ########################## GETTING PROBLEM IN BELLOW CODE ######################### -->
{% for comment in object.comments.all %}
{% if user.is_authenticated %}
{{ comment.create_date }}
{{ comment.text|safe|linebreaks }}
{{ comment.author }}
{% endif %}
{% empty %}
<p>No Comment</p>
{% endfor %}
{% endblock %}
in post_deatil.html i also tried {% for comment in post.comments.all %} but it is also not working

Since you did not specify a related_name=… parameter [Django-doc], the related_name is by default comment_set, so you iterate over the comments with:
{% for comment in object.comment_set.all %}
…
{% endfor %}
Note: It is normally better to make use of the settings.AUTH_USER_MODEL [Django-doc] to refer to the user model, than to use the User model [Django-doc] directly. For more information you can see the referencing the User model section of the documentation.

How to limit the number of items displayed in Django app

I have this Django model in my newspaper app:
class Article(models.Model):
title = models.CharField(max_length=255)
body = models.TextField()
date = models.DateTimeField(auto_now_add=True)
author = models.ForeignKey(
get_user_model(),
on_delete=models.CASCADE,
)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('article_detail', args=[str(self.id)])
It currently displays all articles but I want to limit what is displayed to the 3 most recent articles. How is that done?
This is my view:
class ArticleListView(LoginRequiredMixin, ListView):
model = Article
template_name = 'article_list.html'
login_url = 'login'
This is the html template:
{% extends 'base.html' %}
{% block title %}Articles{% endblock title %}
{% block content %}
{% for article in object_list %}
<div class="card">
<div class="card-header">
<span class="font-weight-bold">{{ article.title }}</span> ·
<span class="text-muted">by {{ article.author }} | {{ article.date }}</span>
</div>
<div class="card-body">
<p>{{ article.body }}</p>
Edit
Delete
</div>
<div class="card-footer">
{% for comment in article.comments.all %}
<p>
<span class="font-weight-bold">{{ comment.author }} ·</span>
{{ comment }}
</p>
{% endfor %}
</div>
</div>
<br />
{% endfor %}
{% endblock content %}

In your (assumed) ListView you should define the queryset, something like
class ArticleListView(LoginRequiredMixin, ListView):
model = Article
template_name = 'article_list.html'
login_url = 'login'
queryset = Article.objects.order_by('-date')[:3]
More on this here.

Django Foreign Key class not showing

The goal is to have a dashboard show a list of users in your area. The list of users works and it shows the Username. The only issue is I can't get the users images (ideally just have 1st image) to show. There are no error messages currently. Just nothing appearing.
models.py
class Images(models.Model):
image = models.ImageField(upload_to='profile_image', null=True, default='profile_image/none/no-img.png')
user = models.ForeignKey(User, on_delete=models.CASCADE, null=False)
class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
bio = models.TextField(max_length=500, blank=True, null=True)
birth_date = models.DateField(null=True, blank=True)
...
views.py
class DashboardView(TemplateView):
template_name = 've/cp/dashboard.html'
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(DashboardView, self).dispatch(*args, **kwargs)
def get(self, request, pk=None):
users = User.objects.exclude(id=request.user.id)
try:
favorite = Favorite.objects.get(current_user=request.user)
favorites = favorite.users.all()
except Favorite.DoesNotExist:
favorites = None
args = {
# 'users': users, 'favorites':favorites, 'images': images,
}
return render(request, self.template_name, args)
dashboard.html
<div class="col-12">
<h2>People near you</h2>
{% for user in users %}
<a href="{% url 've:view_profile_with_pk' pk=user.pk %}">
<!--THIS WORKS-->
<h4>{{ user.username }}</h4>
<p>{{ user.profile.bio }}</p>
<!--But not this... why..-->
<p>{{ user.images.image.url }}</p>
'''
Or this.. However it does work on view_profile page where
there is a pk. Seem like it's not finding images for users,
as this results in a "No images message on localhost
'''
{% if images %}
{% for img in images %}
<a href="{{ user.img.image.url }}" target="_blank">
<img src="{{ user.img.image.url }}" class="" style="max-width: 300px">
</a>
{% endfor %}
{% else %}
<p>No images</p>
{% endif %}
</a>
<!-- Favorites works great -->
{% if not user in favorites %}
<a href="{% url 've:change_favorites' operation='add' pk=user.pk %}">
<button type="button" class="btn btn-success">Add Favorite</button>
</a>
{% endif %}
{% endfor %}
</div>

You can get user's images direcly from user object using images_set attribute.
In your case you can do something like this:
{% for user in users %}
{% with first_image=user.images_set.first %}
{% if first_image %}
<a href="{{ first_image.image.url }}" target="_blank">
<img src="{{ first_image.image.url }}" class="" style="max-width: 300px">
{% endif %}
{% endwith %}
{% endfor %}