I'm getting a NoReverse match error. I've read several posts about this to find the answer, but I'm not seeing a solution.
This is a simple blog webapp for displaying posts in chronological order. The error is related to the edit_post function in "views.py." My suspicion is that the error has to do with trying to store the posts.id as an argument when modifying the post. I've tried removing the post.id in the offending line below and it will load the page. The problem is that if I do that, I cannot load the page for editing specific posts after that.
I don't understand what am I missing. I've looked at a number of posts dealing with this error, and I cannot identify the problem with my specific scenario. Any help is very much appreciated.
My error:
NoReverseMatch at /
Reverse for 'edit_posts' with arguments '('',)' and keyword arguments '{}' >not found. 1 pattern(s) tried: ['edit_posts(?P\d+)/']
Here is the offending line in the home page, "index.html":
<p>
edit post
</p>
Index view:
def index(request):
"""The home page for Blog."""
posts = BlogPost.objects.order_by('date_added')
context = {'posts': posts}
return render(request, 'blogs/index.html', context)
My "urls.py":
urlpatterns = [
# Home page
url(r'^$', views.index, name='index'),
# url(r'^posts/$', views.posts, name='posts'),
# Page for adding a new post.
url(r'^new_post/$', views.new_post, name='new_post'),
# Page for editing posts.
url(r'^edit_posts(?P<posts_id>\d+)/$', views.edit_posts,
name='edit_posts'),
]
edit_posts view:
def edit_posts(request, posts_id):
"""Edit an existing post."""
posts = BlogPost.objects.get(id=posts_id)
if request.method != 'POST':
# Initial request; pre-fill form with the current entry.
form = PostForm(instance=posts)
else:
# POST data submitted; process data.
form = PostForm(instance=posts, data=request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect(reverse('blogs:index',
args=[posts.id]))
context = {'posts': posts, 'form': form}
return render(request, 'blogs/edit_posts.html', context)
Template for the "edit_posts.html" page:
{% extends "blogs/base.html" %}
{% block content %}
<p>Edit an existing post:</p>
<form action="{% url 'blogs:edit_posts' post.id %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">save changes</button>
</form>
{% endblock content %}
In your template, posts - as the name implies - is a queryset, ie a list of BlogPost objects. That queryset doesn't have an id attribute; only the individual posts within that list do.
If you want to link to a specific post, you need to loop through that list, and use the id of each post in the loop:
{% for post in posts %}
<p>
edit post
</p>
{% endfor %}
Related
I am trying to create a way to edit individual blog posts from their individual html. Here are the relevant files and trace back. I am somewhat understanding that the issue lies in blog_post.id being due to the fact that blog_post has not carried over from the for loop on blog_posts.html. I have read up on others having this issue and they all structured their pages to have the edit button being inside the original for loop, which makes sense in hindsight. BUT now that I have run into this issue, I'm determined to understand how I can solve it without going back and restructuring my pages to align with the others I saw.
urls.py
from django.urls import path
from . import views
app_name = 'blogs'
urlpatterns = [
# Home page
path('', views.index, name='index'),
path('blog_posts/', views.blog_posts, name='blog_posts'),
path('blog_posts/<int:blog_post_id>/', views.blog_post, name='blog_post'),
path('new_blog_post/', views.new_blog_post, name='new_blog_post'),
path('edit_blog_post/<int:blog_post_id>/', views.edit_blog_post, name='edit_blog_post'),
]
views.py
from .models import BlogPost
from .forms import BlogPostForm
def index(request):
"""Home page for Blog."""
return render(request, 'blogs/index.html')
def blog_posts(request):
"""Show all Blog Posts."""
blog_posts = BlogPost.objects.order_by('date_added')
context = {'blog_posts': blog_posts}
return render(request, 'blogs/blog_posts.html', context)
def blog_post(request, blog_post_id):
"""Show details of an individual blog post."""
blog_post = BlogPost.objects.get(id=blog_post_id)
title = blog_post.title
id = blog_post_id
date = blog_post.date_added
text = blog_post.text
context = {'title': title, 'text': text, 'date': date}
return render(request, 'blogs/blog_post.html', context)
def new_blog_post(request):
"""Add a new blog post"""
if request.method != 'POST':
# No data submitted, create a blank form.
form = BlogPostForm()
else:
# POST data submitted, process data.
form = BlogPostForm(data=request.POST)
if form.is_valid():
form.save()
return redirect('blogs:blog_posts')
# Display a blank or invalid form.
context = {'form': form}
return render(request, 'blogs/new_blog_post.html', context)
def edit_blog_post(request, blog_post_id):
"""Edit an existing blog post's title or text."""
blog_post = BlogPost.objects.get(id=blog_post_id)
if request.method != 'POST':
# Initial request, prefill with the current data.
form = BlogPostForm(instance=blog_post)
else:
# POST data submitted; process new data.
form = BlogPostForm(instance=blog_post, data=request.POST)
if form.is_valid():
form.save()
return redirect('blogs:blog_post', blog_post_id=blog_post.id)
context = {'blog_post': blog_post, 'form': form}
return render(request, 'blogs/edit_blog_post.html', context)
models.py
from django.db import models
class BlogPost(models.Model):
"""A post the user is posting on their blog."""
title = models.CharField(max_length=200)
text = models.TextField()
date_added = models.DateTimeField(auto_now_add=True)
def __str__(self):
"""Return a string representation of the model"""
return f"{self.title.title()}"
blog_posts.html
{% extends 'blogs/base.html' %}
{% block content %}
<p>Blog Posts</p>
<ul>
{% for blog_post in blog_posts %}
<li>
{{ blog_post }}
</li>
{% empty %}
<li>No posts have been made yet.</li>
{% endfor %}
</ul>
Add a new blog post
{% endblock content %}
blog_post.html
{% extends 'blogs/base.html' %}
{% block content %}
<p>Blog Post: {{ title }}</p>
<p>Entry:</p>
<p>{{ text }}</p>
<p>{{ date }}</p>
<p>
Edit Blog Post
</p>
{% endblock content %}
edit_blog_post.html
{% extends "blogs/base.html" %}
{% block content %}
<p>
{{ blog_post }}
</p>
<p>Edit Blog Post</p>
<form action="{% url 'blogs:edit_blog_post' blog_post.id %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">Save Changes</button>
</form>
{% endblock content %}
Reverse for 'edit_blog_post' with arguments '('',)' not found. 1 pattern(s) tried: ['edit_blog_post/(?P<blog_post_id>[0-9]+)/\Z']
3 {% block content %}
4
5 <p>Blog Post: {{ title }}</p>
6
7 <p>Entry:</p>
8
9 <p>{{ text }}</p>
10 <p>{{ date }}</p>
11
12 <p>
13 Edit Blog Post
14 </p>
15
16 {% endblock content %}
If I've read the question correctly, You're getting the error becuase you are not providing the necessary ID to the URL construction part of your template.
You're separating out the elements (date, content etc) to send to the template, but not passing the ID at the same time. You could send the ID in as a separate context variable, but that's extra typing for no real reward.
It's easiest to pass in the post itself via context and refer to its attributes in the template - I think it makes it easier to read also. That way the ID is there when you need to contruct the edit link, and if you change the model to possess extra fields, you don't need to convert and add to the context as the whole post is already there.
views.py
def blog_post(request, blog_post_id):
"""Show details of an individual blog post."""
blog_post = BlogPost.objects.get(id=blog_post_id) #this is all we need
context = {"blog_post_context": blog_post}
return render(request, 'blogs/blog_post.html', context)
blog_post.html
{% extends 'blogs/base.html' %}
{% block content %}
<p>Blog Post: {{ blog_post_context.title }}</p>
<p>Entry:</p>
<p>{{ blog_post_context.text }}</p>
<p>{{ blog_post_context.date }}</p>
<p>
Edit Blog Post
</p>
{% endblock content %}
If that all works, look into using get_object_or_404 rather than Post.objects.get for some additional robustness.
I assume you got the error when you try visiting the blog_post.html page. If I'm correct, then here's an approach you could take...
In your views.py
def blog_post(request, blog_post_id):
"""Show details of an individual blog post."""
# blog_post = BlogPost.objects.get(id=blog_post_id)
blog_post = get_object_or_404(id=blog_post_id) # Recommended
# Commented lines below are somewhat not necessary...
# title = blog_post.title
# id = blog_post_id
# date = blog_post.date_added
# text = blog_post.text
context = {'blog_post': blog_post}
return render(request, 'blogs/blog_post.html', context)
edit_blog_post.html is expecting an object called blog_post to be able to access the blog_post.id for {% url 'blogs:edit_blog_post' blog_post.id %}.
Now within the edit_blog_post.html file.
{% block content %}
<p>Blog Post: {{ blog_post.title }}</p>
<p>Entry:</p>
<p>{{ blog_post.text }}</p>
<p>{{ blog_post.date_added }}</p>
<p>
Edit Blog Post
</p>
{% endblock content %}
This is the error I get when clicking on Edit post under any one of the posts. Would appreciate any help as all this django stuff is confusing me but trying my best to learn. My new post function works and clicking blog/posts to go to the overview page for the blog or to look at all the posts works as well.
NoReverseMatch at /edit_post/1/
Reverse for 'posts' with arguments '(1,)' not found. 1 pattern(s) tried: ['posts/$']
Error during template rendering
In template C:\Users\seng\Desktop\Python projects\c19\nineteen_one\blogs\templates\blogs\base.html, error at line 0
urls.py
"""Defines url paterns for blogs"""
from django.urls import path
from . import views
app_name = 'blogs'
urlpatterns =[
#Home page
path('', views.index, name='index'),
# Page that shows all posts/
path('posts/', views.posts, name='posts'),
#Page for adding a new blogpost
path('new_post/', views.new_post, name='new_post'),
#Page for editing a post
#maybe remove the id?
path('edit_post/<int:post_id>/', views.edit_post, name='edit_post'),
]
views.py
from django.shortcuts import render, redirect
from .models import BlogPost
from .forms import BlogPostForm
# Create your views here.
def index(request):
"""The home page for blogs"""
return render(request, 'blogs/index.html')
def posts(request):
"""Show all blogposts"""
posts = BlogPost.objects.order_by('date_added')
context = {'posts': posts}
return render(request, 'blogs/posts.html', context)
def new_post(request):
"""Add a new blogpost"""
if request.method != 'POST':
#No data submitted; create a blank form.
form = BlogPostForm()
else:
#POST data submitted, process data
form = BlogPostForm(data=request.POST)
if form.is_valid():
form.save()
return redirect('blogs:posts')
#Display a blank or invalid form
context = {'form': form}
return render(request, 'blogs/new_post.html', context)
def edit_post(request, post_id):
"""Edit existing post"""
post = BlogPost.objects.get(id=post_id)
if request.method != "POST":
#Initial request, pre-fill form with the current post
form = BlogPostForm(instance=post)
else:
#Post data submitted, process data
form = BlogPostForm(instance=post, data=request.POST)
if form.is_valid():
form.save()
return redirect('blogs:posts', post_id=post.id)
context = {'post':post, 'form':form}
return render(request, 'blogs/edit_post.html', context)
forms.py
from django import forms
from .models import BlogPost
class BlogPostForm(forms.ModelForm):
class Meta:
model = BlogPost
fields = ['text', 'title']
labels = {'text':'This is the text box', 'title' :"Title here"}
edit_post.html
{% extends "blogs/base.html" %}
{% block content %}
<p>{{ post }}</p>
<p>Edit post:</p>
<form action="{% url 'blogs:edit_post' post.id %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">Save changes</button>
</form>
{% endblock content %}
posts.html
{% extends "blogs/base.html" %}
{% block content %}
<p>Posts</p>
<ul>
{% for post in posts %}
<li>
<p>{{ post }}</p>
<p>
Edit post
</p>
</li>
{% empty %}
<li>No posts have been added yet.</li>
{% endfor %}
</ul>
Add a new post
{% endblock content %}
new_post.html
{% extends "blogs/base.html" %}
{% block content %}
<p>Add a new post:</p>
<form action="{% url 'blogs:new_post' %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">Add post</button>
</form>
{% endblock content %}
The issue is with this line in edit_post.html:
<p>{{ post }}</p>
If you are editing the post with id 1, then this link is to the url /posts/1. But that has no match in your urls.py file.
Either you need to remove the post.id parameter from the link, or create a view and a corresponding path in urls.py for this link.
I am setting up a simple blog site with Django, and run into this error when trying to link to a page that allows users to edit existing blog posts.
Reverse for 'edit_post' with arguments '('',)' not found. 1 pattern(s) tried: ['edit_post/(?P<title_id>[0-9]+)/$']
If I understand this error correctly, it means that Django can't find a urlpattern that matches the url being requested. To my eyes I have the urlpattern set up correctly, but I still get the error.
The link in question appears on the text.html template, which is the template that displays the text of a particular blog post.
Here is the relevant code:
urls.py
"""Defines URL patterns for blogs."""
from django.urls import path
from . import views
app_name = 'blogs'
urlpatterns = [
# Home page, shows all posts in chronological order.
path('', views.index, name='index'),
# A page to show the text of a specific post.
path('text/<int:title_id>/', views.text, name='text'),
# Page for adding a new post.
path('new_post/', views.new_post, name='new_post'),
# Page for editing a post.
path('edit_post/<int:title_id>/', views.edit_post, name='edit_post'),
]
views.py
from django.shortcuts import render, redirect
from .models import BlogPost
from .forms import BlogPostForm
def index(request):
"""The home page for blogs, shows all posts."""
titles = BlogPost.objects.order_by('date_added')
context = {'titles': titles}
return render(request, 'blogs/index.html', context)
def text(request, title_id):
"""Show a single post title and its text."""
title = BlogPost.objects.get(id=title_id)
text = title.text
context = {'title': title, 'text': text}
return render(request, 'blogs/text.html', context)
def new_post(request):
"""Add a new post."""
if request.method != 'POST':
# No data submitted; create a new form.
form = BlogPostForm()
else:
# POST data submitted; process data.
form = BlogPostForm(data=request.POST)
if form.is_valid():
new_post = form.save(commit=False)
new_post.save()
return redirect('blogs:index')
# Display a blank or invalid form.
context = {'form': form}
return render(request, 'blogs/new_post.html', context)
def edit_post(request, title_id):
"""Edit an existing post."""
post = BlogPost.objects.get(id=title_id)
if request.method != 'POST':
# Initial request: pre-fill form with the current post.
form = BlogPostForm(instance=post)
else:
# Post data submitted; process data.
form = BlogPostForm(instance=post, data=request.POST)
if form.is_valid():
form.save()
return redirect('blogs:index')
context = {'post': post, 'form': form}
return render(request, 'blogs/edit_post.html', context)
index.html (this is the homepage for the blog)
{% extends "blogs/base.html" %}
{% block content %}
<p>Blog is a generic site for a blogger to post content for their audience.</p>
<p>Posts</p>
<ul>
{% for title in titles %}
<li>
{{ title }}
</li>
{% empty %}
<li>No posts have been added yet.</li>
{% endfor %}
</ul>
Create a new post
{% endblock content %}
text.html (this page displays the text content of a particular post, and also the link to edit the post)
{% extends "blogs/base.html" %}
{% block content %}
<p>Title: {{ title }}</p>
<p>{{ text }}</p>
Edit post
{% endblock content %}
edit_post.html (this page should display the existing post and allow it to be edited)
{% extends "blogs/base.html" %}
{% block content %}
<p>Edit post:</p>
<p>Title:</p>
<form action="{% url 'blogs:edit_post' title.id %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">Save changes</button>
</form>
{% endblock content %}
How the edit_post function in views.py should work (in theory) is to create an instance based upon the post's title id, and then allowing the user to edit it and save changes.
I'm not sure where I'm going wrong here and any suggestions are greatly appreciated.
The name of the post object you pass to the template, is not title, but post:
{% extends "blogs/base.html" %}
{% block content %}
<p>Edit post:</p>
<p>Title:</p>
<form action="{% url 'blogs:edit_post' post.pk %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">Save changes</button>
</form>
{% endblock content %}
If you use title.id, it will not find that variable, and thus this will be resolved to the empty string. If you use post.id, or post.pk, it will resolve to the .id field, or primary key of the post object.
path('administration/delete-post/', administration_views.delete_upload, name='delete_upload'),
path('administration/delete-post/<slug:post_slug>', administration_views.delete_upload, name='delete_upload'),
For some reason, when I added delete class, I had to add two url patterns.
When I comment out the first path, It gives me an error of
Reverse for 'NoReverseMatch at /administration/
delete_upload' with no arguments not found. 1 pattern(s) tried: ['administration/delete\\-post/(?P<post_slug>[-a-zA-Z0-9_]+)$']
I even stated the slugs on html.
{% for post in posts %}
Delete Upload
{% endif %}
With two same url patterns, it worked fine somehow, but now I want to add a confirmation page, and it's causing an error again.
views.py
def delete_upload(request, post_slug):
post = get_object_or_404(VideoPost, slug=post_slug)
if request.method == "POST":
post.delete()
context = {
"post": post
}
return render(request, "administration/confirm_delete.html", context)
confirm_delete.html
{% block content %}
<form action="." method="POST">{% csrf_token %}
<h1>Are you sure you want to delete</h1>
<p>{{post.title}}</p>
Cancel<input type="submit" value="Confirm">
</form>
{% endblock %}
error
TypeError at /administration/delete-post/
delete_upload() missing 1 required positional argument: 'post_slug'
It directs me to confirm_delete page correctly with the slugs on url, but when I click confirm, the slug is gone on the url and it's causing the error it seems.
I see the problem, but I can't fix it... please help.
Thank you for any helps
Remove path('administration/delete-post/', in your urls.py file
In your HTML template pass your post.slug along with the url namespace
{% for post in posts %}
Delete Upload
{% endif %}
You are using url template tag incorrectly. In html you need replace
Delete Upload
with
Delete Upload
I'm working on a Django site that displays a list of projects. You go to a page, you see a project, you click it, and you can then see project details and have the option to edit the page.
For each individual project, I use a template called project.html. Then on that page, I have a link to edit_project.html
Edit Project
Whenever I try to load the project page to view, I get this error:
Reverse for 'edit_project' with arguments '('',)' not found. 1
pattern(s) tried: ['edit_project/(?P\d+)/$']
I checked the urls, and they seemed fine. So, I tried hard-coding a project id that I knew was in the database. For example, I called:
Edit Project
instead of calling that same thing with "project.id". When I did that, the error went away.
Why does this work with a hard-coded value instead of a project.id variable?
I also tried deleting the database and all the migrations in case something strange was happening there. I got the same issue though.
Here is the code I used to set everything up in case it is helpful.
project.html
{% extends "profile/base.html" %}
{% block content %}
<p>
Edit Project
</p>
<p>Status: {{ status }}</p>
{% endblock content %}
edit_project.html
{% block content %}
<p>{{ project }}</p>
<p>Edit project:</p>
<form action="{% url 'profile:edit_project' project.id %}" method='post'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">Save Changes</button>
</form>
{% endblock content %}
views.py
#login_required
def edit_project(request, project_id):
"""Edit an existing project"""
project = Project.objects.get(id=project_id)
#Make sure the project belongs to the owner
if project.owner != request.user:
return Http404
if request.method != 'POST':
#Initial request; pre-fill form with the current entry
form = ProjectForm(instance=project)
else:
#POST data submitted; process data
form = ProjectForm(instance=project, data=request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect(reverse('profile:project',args=[project.id]))
context = {'project':project, 'form':form}
return render(render, 'profile/edit_project.html', context)
(project) forms.py
class DateInput(forms.DateTimeInput):
input_type = 'date'
class ProjectForm(forms.ModelForm):
class Meta:
model = Project
fields = ['name','description','status', 'project_type', 'start_date','end_date', 'due_date']
labels = {'name':'Name', 'description':'Description:', 'status':'Status', 'project_type':'Project Type',
'start_date':'Start Date', 'end_date':'End Date', 'due_date': 'Due Date',}
widgets ={'description':forms.Textarea(attrs={'cols':80}),'start_date':DateInput(),
'end_date':DateInput(),'due_date':DateInput()}
urls.py
urlpatterns = [
#Home page
url('^$', views.index, name='index'),
#Show all projects
url('projects/$', views.projects, name='projects'),
#Details for single project
url('^projects/(?P<project_id>\d+)/$', views.project, name='project'),
#Page for editing a single project
url('^edit_project/(?P<project_id>\d+)/$', views.edit_project, name='edit_project'),
]