Develop Reference

Django Show all posts from a single user

I'm building an instagram-ish clone in Django. I have the basic functionality working, where a user can post an image, and this is displayed on the main page. I would like to make a 'user page' that only displays posts from a user. For example, example.com/foobar would only display posts from the user 'foobar'.
I believe i have the urls.py and template working correctly, but I can not figure out how to only iterate through items and pull out ones of a specific user. I realize this should be a queryset of some kind, but other than that I'm stumped. Should this be its own class, or could I extend the existing PostList class to pull out a single author's posts?
post_detail.html - gets all the images stored in the database, this works fine.
{% for post in object_list %}
<td><img src="{{ post.image.url }}" width="300"></td>
{% if forloop.counter|modulo:4 %}
</tr><tr>
{% endif %}
{% endfor %}
profile.html - shows all posts from a user (as in example.com/foobar)
<table>
<tr>
{% for post in object_list %}
<td><img src="{{ post.image.url }}" width="300"></td>
{% if forloop.counter|modulo:4 %}
</tr><tr>
{% endif %}
{% endfor %}
</tr>
</table>
urls.py - I believe this works correctly.
urlpatterns = [
path('admin/', admin.site.urls),
path('', PostList.as_view(), name='list'),
path('<str:username>/', Profile.as_view(), name='user_profile'),
views.py:
from posts.models import Post
class PostList(ListView):
ordering = ['-created']
paginate_by = 12
model = Post
class Profile(ListView):
template_name = 'posts/profile.html'
UserName = self.kwargs.get("username")
queryset = PostList.queryset
.filter(author = UserName)
return queryset
models.py:
class Post(models.Model):
image = models.ImageField()
author = models.ForeignKey(User, on_delete=models.CASCADE)
created = models.DateTimeField(auto_now_add=True)
modified = models.DateTimeField(auto_now=True)

You can override get_queryset():
class ProfileView(ListView):
template_name = 'posts/profile.html'
model = Post
def get_queryset(self, **kwargs):
return super().get_queryset(**kwargs).filter(
author__username=self.kwargs['username']
)
Note: In Django, class-based views (CBV) often have a …View suffix, to avoid a clash with the model names.
Therefore you might consider renaming the view class to ProfileView, instead of Profile.

How do I get reverse reference in Django template?

Apologies if the title doesn't make much sense. I don't quite understand what I lack in knowledge.
I have a Post and Comment models in my Django project. What I'm trying to do is list out all the Blog posts, and show NUMBER OF COMMENTS OF EACH POST. Please see my codes below.
models.py
class Blog(models.Model):
objects = models.Manager()
title = models.CharField(max_length=100, blank=True)
body = models.CharField(max_length=10000, blank=True)
created_at = models.DateField(auto_now_add=False)
class Comment(models.Model):
objects = models.Manager()
post = models.ForeignKey(Blog, on_delete=models.CASCADE, related_name='comment')
views.py
def main_page(request):
all_blogs = Blog.objects.all()
context = {
'blog' : blog,
}
return render(request, 'main/home.html', context)
template
{% for b in blog %}
<div>
<p>{{b.title}}</p>
<div>
{{WHERE THE NUMBER OF THIS POST'S COMMENTS IS DISPLAYED}}
</div>
</div>
{% endfor %}
All I need is the number of the comments, but have no idea how to do it. Is there a way to make this possible in the template? Or do I have to add some codes in views.py?

You can annotate the Blog objects with the number of related Comments with:
from django.db.models import Count
def main_page(request):
all_blogs = Blog.objects.annotate(
num_comments=Count('comment')
)
context = {
'blogs' : blogs
}
return render(request, 'main/home.html', context)
The Blog objects that arise from that queryset will have an extra attribute .num_comments with the number of related comments:
{% for blog in blogs %}
<div>
<p>{{ blog.title }}</p>
<div>
{{ blog.num_comments }}
</div>
</div>
{% endfor %}

Access Many-to-Many field within Django template

I have the following blog project :
models.py:
from django.db import models
from django.utils import timezone
class Post(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField(default=timezone.now)
categories = models.ManyToManyField('Category')
def __str__(self):
return self.title
class Category(models.Model):
title = models.CharField(max_length=200)
def __str__(self):
return self.title
# Change the name in Admin from categorys to categories
class Meta:
verbose_name_plural = "categories"
views.py:
from django.shortcuts import render
from .models import Post, Category, Comment
def getPosts(request):
posting = Post.objects.all().order_by('-pub_date')
categories = Category.objects.all()
context = {
'posting':posting,
'categories':categories,
}
return render(request, 'posts/getPosts.html', context)
getPosts.html template :
{% if posting %}
{% for article in posting %}
<h3>{{article.title}}</h3>
<ul>{{article.body}}</ul>
<ul>Posted : {{article.pub_date}}</ul>
<ul>
<em>Found in category : </em>
{{ article.categories }}
{{ article.categories.all }}
{% for category in categories %}
{{category.title}}
{% endfor %}
</ul>
{% endfor %}
{% endif %}
I have three posts, which all display properly, but
{{article.categories}} is giving me:
posts.Category.None
{{article.categories.all}} gives me
QuerySet [<Category: Diving>]
And the second loop outputs the list of all categories, which I expected as just a test run:
Kit & Packing Diving Places Tips Private
I am trying to simply pull through the category name for each post, which has been selected in the admin panel and saved through the admin panel.
I have tried what feels like a thousand different suggestions, such as changing the view to category = post.category_set.all(), and have been researching this for days now, but am getting no-where.

You already have the right answer; article.categories.all, which you should loop over.
{% for category in article.categories.all %}
{{category.title}}
{% endfor %}
You don't need the categories value in the view at all.

How do I iterate through a ManyToManyField in django-jinja project?

I am trying to create a blog app which has posts and each posts have title, date, link and tags.
This is my models.py
# models.py
from django.db import models
class Tag(models.Model):
name = models.CharField(max_length=20)
def __str__(self):
return self.name
class Meta:
ordering = ('name',)
class Post(models.Model):
title = models.CharField(max_length=300)
date = models.DateTimeField()
link = models.URLField()
tags = models.ManyToManyField(Tag)
def __str__(self):
return self.title
#property
def tags_name(self):
return [x.name for x in self.tags]
class Meta:
ordering = ('date',)
This is my views.py
# views.py
from django.conf.urls import url, include
from django.views.generic import ListView
from blog.models import Post
urlpatterns = [
url(r'^$', ListView.as_view(queryset=Post.objects.all().order_by("-date"), template_name="blog/blog_list.html")),
]
This is my blog_list.html
<!-- blog_list.html -->
{% extends "mysite/layout.html" %}
{% block content %}
<h1>my blog posts</h1>
<ul>
{% for post in object_list %}
<li><span class="title">{{ post.title }}</span></li>
<p>{{ post.date|date:"d-m-Y" }}</p>
{% endfor %}
</ul>
{% endblock %}
{% block sidebar %}
<h4 id="sidenav">tags</h4>
{% for post in object_list %}
<ul>
<!-- I want to show the tags here -->
</ul>
{% endfor %}
{% endblock %}
In the blog_list.html, I am showing all the post details and on the sidebar, I want to show all the tags present from all the blog posts available. Since post.tags is ManyToManyField, how can I iterate through it?

You want to use .all in the template to get all the elements in the relationship:
{% for tag in post.tags.all %}
{{ tag }}
{% endfor %}
Thanks to #hansTheFranz for correcting my bracket issue.
Regarding not repeating tags, this would be very difficult with the current context. You might want to look into instead getting the posts in your View and extracting the tags there, where you have more freedom to check for duplicates. Something like this:
def tags(request):
posts = Post.objects.all()
tag_list = []
for post in posts:
tags = post.tags.all()
for tag in tag:
if not (tag in tag_list):
tag_list.append(tag)
context_dict = { "tags": tag_list, "posts": posts }
return render(request, 'blog/blog_list.html', context_dict)
urlpatterns = [
url(r'^$', tags, name="tags"),
]
And then change your template to be more like:
{% block sidebar %}
<h4 id="sidenav">tags</h4>
<ul>
{% for tag in tags %}
<li>{{ tag }}</li>
{% endfor %}
</ul>
{% endblock %}
Additionally, instead of referencing object_list you can now access the list of posts by referencing posts, because we have defined the list of posts as such in our context dictionary, which is being passed to the template.
I'm afraid I have not tested this and it may not be very efficient, but roughly speaking it should work. A lecturer at my university wrote this book: http://www.tangowithdjango.com/book17/, which encourages more of a style of writing views as I have done: separate from the URLs. If anything I've done seems unclear or contrary, you may want to have a look at the book and see if anything there makes more sense.

Filter on many-to-one model

I want to be able assign users vehicle registrations, and when the user logs into the website their home page should have a list of vehicle regs they own.
However I cannot get the model class to filter on the foreign key.
views.py
#login_required
def home(request):
# This is the basic user landing Page
veh_list = Vehicle.objects.filter(UserProfile.user)
return render(request, 'portal/home.html', {"veh_list": veh_list})
model.py
from django.db import models
from django.contrib.auth.models import User
# Create your models here.
class UserProfile(models.Model):
# This line is required. Links UserProfile to a User model instance.
user = models.OneToOneField(User)
# The additional attributes we wish to include.
compName = models.CharField(max_length = 20)
milkco = models.IntegerField()
# Override the __unicode__() method to return out something meaningful!
def __unicode__(self):
return self.user.username
class Vehicle(models.Model):
vehid = models.CharField(max_length = 10)
company = models.ForeignKey(UserProfile, default = 1)
class Meta:
db_table = "vehicle"
def __unicode__(self):
return self.vehid
home.html
<!DOCTYPE html>
{% extends 'portal/base.html' %}
{% block title %}{{user.first_name }} {{ user.last_name }} Portal{% endblock %}
{% block content %}
<p>This is the home Page</p>
{% if user.is_authenticated %}
<h4>Optiload says... hello {{ user.first_name }} {{ user.last_name }}!</h4>
{% endif %}
{% for veh in veh_list %}
{{ veh}}
{% endfor %}
{% if user.is_authenticated %}
Logout<br/>
{% endif %}
{% endblock %}
Could someone help me with where I'm going wrong?
Thanks

Django offers a powerful and intuitive way to “follow” relationships in lookups, taking care of the SQL JOINs for you automatically, behind the scenes. To span a relationship, just use the field name of related fields across models, separated by double underscores, until you get to the field you want.
So your query should look like
veh_list = Vehicle.objects.filter(company__user=request.user)
Reference

You cannot make queries with unnamed arguments:
Vehicle.objects.filter(UserProfile.user)
In this case you want:
Vehicle.objects.filter(company=[your user])