Django - NoReverseMatch at /project/3/evillio - django

Question

I'm working on a portfolio project and i face a strange problem when trying to list a project, ( class-based-views-DetailView). More specifically when trying to list a project for example /project/3/evillio i got following error Reverse for 'project-detail' with arguments '('', '')' not found. 1 pattern(s) tried: ['project/(?P<pk>[0-9]+)/(?P<slug>[-a-zA-Z0-9_]+)$'] but when i add a new project, i'm able to list /project/3/evillio with no problem, however i got the same error on the next project /project/4/urban.
For example i add 2 projects in project table (using Postgres) then going to list details of each project. Click on project1 and works fine. Then click on project 2 and i got error above. Then i add a third project in project table and going to list details of each project. Click on project1 works fine, click on project2 works fine, click on project3 and i got the same error as on project2 before adding project3.
I hope is more clear.
urls.py
path('project/<int:pk>/<slug:slug>', WorkProjectsDetailView.as_view(), name='project-detail'),
views.py
class IndexView(ListView):
model = Project
template_name = 'pages/index.html'
context_object_name = 'projects'
def get_context_data(self, **kwargs):
context = super(IndexView, self).get_context_data(**kwargs)
context['slider_projects'] =
Project.objects.all().filter(slider_project=True)
return context
class WorkProjectsView(ListView):
model = Project
template_name = 'work/work.html'
queryset = Project.objects.all()
context_object_name = 'projects'
ordering = ['-date_created']
def get_context_data(self, *, object_list=None, **kwargs):
context = super(WorkProjectsView, self).get_context_data(**kwargs)
context['categories'] = Category.objects.all()
return context
class WorkProjectsDetailView(DetailView):
model = Project
template_name = 'work/project-detail.html'
context_object_name = 'single_project'
def get_context_data(self, **kwargs):
context = super(WorkProjectsDetailView, self).get_context_data(**kwargs)
context['next'] = Project.objects.filter(id__gt=self.kwargs['pk']).order_by('pk').first()
return context
work.html
<div class="projects-list gallery">
{% if projects %}
{% for project in projects %}
<div class="item brand">
<a href="{% url 'project-detail' pk=project.pk slug=project.slug %}" class="effect-ajax" data-dsn-ajax="work"
data-dsn-grid="move-up">
<img class="has-top-bottom" src="{{ project.featured_image.url }}" alt="" />
<div class="item-border"></div>
<div class="item-info">
<h5 class="cat">{{ project.category }}</h5>
<h4>{{ project.title }}</h4>
<span><span>View Project</span></span>
</div>
</a>
</div>
{% endfor %}
{% else %}
<div class="col-lg-8">
<p>No Projects Available</p>
</div>
{% endif %}
</div>
index.html
{% for project in slider_projects %}
<div class="work-item slick-slide">
<img class="has-top-bottom" src="{{ project.featured_image.url }}" alt="">
<div class="item-border"></div>
<div class="item-info">
<a href="{% url 'project-detail' pk=project.pk slug=project.slug %}" data-dsn-grid="move-up" class="effect-ajax">
<h5 class="cat">{{ project.category}}</h5>
<h4>{{ project.title }}</h4>
<span><span>View Project</span></span>
</a>
</div>
</div>
{% endfor %}
project-detail.html
{% extends 'base.html' %}
{% load static %}
{% block content %}
<main class="main-root">
<div id="dsn-scrollbar">
<header>
<div class="headefr-fexid" data-dsn-header="project">
<div class="bg w-100" id="dsn-hero-parallax-img" data-dsn-ajax="img">
<div class="bg-image cover-bg" data-overlay="4"
data-image-src="{{ single_project.hero_image.url }}"></div>
</div>
<div class="scroll" data-dsn-animate="ajax">
<span class="background"></span>
<span class="triangle"></span>
</div>
<div class="project-title" id="dsn-hero-parallax-title" style="margin-top: 100px;">
<div class="title-text-header">
<div class="cat">
<span>{{ single_project.category}}</span>
</div>
<span class="title-text-header-inner">
<span data-dsn-animate="ajax">{{ single_project.title }}</span>
</span>
</div>
<div class="sub-text-header" data-dsn-animate="ajax">
<h5>Published</h5>
<span>- {{ single_project.date_created }}</span>
</div>
</div>
<div class="project-page__inner">
<div class="h-100">
<div class="row justify-content-center align-items-end h-100">
<div id="descover-holder" class="col-lg-12 project-meta__content">
<div class="link">
<a target="_blank"
href="https://www.behance.net/gallery/57437111/Under-Armour-Cal?tracking_source=search%7CPhotography">View
Website</a>
</div>
</div>
</div>
</div>
</div>
</div>
</header>
<div class="wrapper">
<div class="root-project">
<div class="container intro-project section-margin">
<div class="intro-text">
<div class="title-cover" data-dsn-grid="move-section" data-dsn-opacity="0.1"
data-dsn-duration="170%" data-dsn-move="0%">
Nile
</div>
<div class="inner">
<h2 data-dsn-animate="text">A whole new brand</h2>
<p data-dsn-animate="up">Striking and powerful Aston Martin Vantage captivates you at
the first sight. We couldn’t resist the temptation to create a series of beautiful
images for this car.</p>
<a class="bottom-link" data-dsn-animate="up"
href="https://www.behance.net/gallery/66646747/Nile" target="_blank">
<span></span>
<span></span>
<div class="content">
<div class="inner">
<p>VISIT SITE</p>
</div>
</div>
</a>
</div>
</div>
</div>
<div class="container section-margin">
<div class="img-box-small dsn-parallax-full" data-dsn-grid="move-up">
<img src="{{ single_project.photo_1.url }}" alt="">
<div class="cap">
<span>Web Design</span>
</div>
</div>
</div>
<div class="container-fluid section-margin">
<div class="img-box-small dsn-parallax-full" data-dsn-grid="move-up" data-dsn-triggerhook="0">
<img src="{{ single_project.photo_2.url }}" alt="" data-dsn-y="30%" data-dsn-scale="1.08">
<div class="cap">
<span>Web Design</span>
</div>
</div>
</div>
<div class="container intro-project section-p section-margin">
<div class="intro-text text-center">
<div class="title-cover" data-dsn-grid="move-section" data-dsn-opacity="0.1"
data-dsn-duration="170%" data-dsn-move="0%">
Nile
</div>
<div class="inner">
<h2 data-dsn-animate="text">
The Brief team has been sincerely committed to
designing great communication around our projects. Our customers love
their
creative work - and so do we!
</h2>
</div>
</div>
</div>
<!--Video-->
<div class=" " data-dsn="video" data-overlay="4" data-dsn-ajax="img">
<video class="image-bg cover-bg dsn-video" controls loop muted>
<source src="{{ single_project.video.url }}" type="video/mp4">
</video>
</div>
<!--<div class="container section-margin">
<div class="img-box-small dsn-parallax-full" data-dsn-grid="move-up">
<img src="{{ single_project.photo_3.url }}" alt="">
<div class="cap">
<span>Web Design</span>
</div>
</div>
</div>-->
<div class="container-fluid section-margin">
<div class="img-box-small dsn-parallax-full" data-dsn-grid="move-up" data-dsn-triggerhook="0">
<img src="{{ single_project.photo_4.url }}" alt="" data-dsn-y="30%" data-dsn-scale="1.08">
<div class="cap">
<span>Web Design</span>
</div>
</div>
</div>
</div>
<div class="next-project" data-dsn-footer="project">
<div id="dsn-next-parallax-img" class="bg">
<div class="bg-image cover-bg" data-overlay="2"
data-image-src="{{ next.featured_image.url }}"></div>
</div>
<div id="dsn-next-parallax-title" class="project-title">
<a href="{% url 'project-detail' next.pk next.slug %}" class="effect-ajax" data-dsn-ajax="next-project">
<div class="title-text-header">
<div class="title-text-header-inner">
<span>{{ next.title }}</span>
</div>
</div>
<div class="sub-text-header">
<h5>Next Project</h5>
</div>
</a>
</div>
</div>
Any help appreciated.

Answer 1

The error you're receiving is because of this line toward the bottom of project-detail.html:
<a href="{% url 'project-detail' next.pk next.slug %}" class="effect-ajax" data-dsn-ajax="next-project">
if there is no next (context["next"]), then django can't figure out the url, and you get the error you're seeing.
Wrap the last segment for the link to "next" with {% if next %}:
{% if next %}
<div class="next-project" data-dsn-footer="project">
<div id="dsn-next-parallax-img" class="bg">
<div class="bg-image cover-bg" data-overlay="2"
data-image-src="{{ next.featured_image.url }}"></div>
</div>
<div id="dsn-next-parallax-title" class="project-title">
<a href="{% url 'project-detail' next.pk next.slug %}" class="effect-ajax" data-dsn-ajax="next-project">
<div class="title-text-header">
<div class="title-text-header-inner">
<span>{{ next.title }}</span>
</div>
</div>
<div class="sub-text-header">
<h5>Next Project</h5>
</div>
</a>
</div>
</div>
{% endif %}