Django 自定义标签问题

Question

Hello Stack Overflow !

I am making a news site in Django as a part of my "internship", I have just started learning web development. I was given a task to make a custom template ( it HAS to be a custom template ) which will render out 3 latest news from a category, and I have to include it as a sidebar on my "article" page.

I tried to write the custom tag, but it's not going to well unfortunately. This is my "last" task for the website, and I'm stuck (like many times before:P )

Here's the thing..everything is working if I include the custom tag on my "list all articles" page, it renders correctly depending on which category I click on.

The thing is, once I try to include my tag into my "single article" page I hit a brick wall. The tag is still working, but is now displaying all of my articles, instead of filtering the articles related to that article's category.

To simplyfiy, If i click on a "health" article to open it, I want the sidebar just to include the articles for the "health" category, I hope that makes sense.

Anyone with a couple of minutes of spare time willing to help me out? :)

My code:

the custom tag:

from django import template
from news.models import Article

register = template.Library()


@register.inclusion_tag("news/categories.html")
def show_results(article):
    article = article.filter()[:3]
    return {'article': article}

HTML template for the tag:

{% load article_extras %}
<div class="articles-filter">
    <ul>
        {% for a in article %}
        <img src="{{ a.article_image.url }}" alt="">
        <h5>{{ a.title }}</h5>
        {% endfor %}
    </ul>

</div>

my models:

from django.db import models
from datetime import datetime
from autoslug import AutoSlugField


class Category(models.Model):
    category_title = models.CharField(max_length=200, default="")

    def __str__(self):
        return self.category_title


class Article(models.Model):
    title = models.CharField('title', max_length=200, blank=True)
    slug = AutoSlugField(populate_from='title', default="",
                         always_update=True, unique=True)
    author = models.CharField('Author', max_length=200, default="")
    description = models.TextField('Description', default="")
    is_published = models.BooleanField(default=False)
    article_text = models.TextField('Article text', default="")
    pub_date = models.DateTimeField(default=datetime.now, blank=True)
    article_image = models.ImageField('Article Image')
    article_category = models.ForeignKey(Category, on_delete="models.CASCADE", default="")
    img2 = models.ImageField('Article Image 2', default="", blank=True)
    img3 = models.ImageField('Article Image 3', default="", blank=True)
    img4 = models.ImageField('Article Image 4', default="", blank=True)
    img5 = models.ImageField('Article Image 5', default="", blank=True)
    img6 = models.ImageField('Article Image 6', default="", blank=True)

    def __str__(self):
        return self.title


class Comment(models.Model):
    post = models.ForeignKey('Article', on_delete=models.CASCADE, related_name='comments')
    author = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(default=datetime.now, blank=True)
    approved_comment = models.BooleanField(default=False)

    def approve(self):
        self.approved_comment = True
        self.save()

    def __str__(self):
        return self.text

the "single article" template where I am trying to include my custom tag:

{% extends "news-base.html" %}

{% load static %}
{% load article_extras %}


{% block article %}

<script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>





<div class="preloader d-flex align-items-center justify-content-center">
  <div class="spinner">
    <div class="double-bounce1"></div>
    <div class="double-bounce2"></div>
  </div>
</div>
{% show_results article %}
<!-- ##### Post Details Area Start ##### -->
<section class="container post-details-area">
  <div class="container single-article-div">
    <hr class="hr-single">
    <h2 class="single-article-titles">{{ article.title }}</h2>
    <hr class="hr-single">
    <img class="single-article-img" src="{{ article.article_image.url }}" alt="">
    <!-- *********************************** -->
    <hr class="hr-single">
    <p>Category: {{ article.article_category }}</p>
    <hr class="hr-single">
    <div class="row justify-content-center">
      <!-- Post Details Content Area -->
      <div class="col-12 col-xl-8">
        <div class="post-details-content bg-white box-shadow">
          <div class="blog-thumb">

          </div>
          <div class="blog-content">
            <div class="post-meta">
              <a href="#">{{ article.pub_date }}</a>
            </div>
            <h3 class="single-article-titles post-title"> {{ article.description }}</h3>
            <hr>

            <!-- Post Meta -->
            <div class="post-meta-2">
              <a href="#"><i class="fa fa-eye" aria-hidden="true"></i> 1034</a>
              <a href="#"><i class="fa fa-thumbs-o-up" aria-hidden="true"></i> 834</a>
              <a href="#"><i class="fa fa-comments-o" aria-hidden="true"></i> 234</a>
            </div>
            <p>{{ article.article_text }}</p>
            <hr />

            {% include "partials/_thumbnails.html" %}

            <hr>
            <p>Author: {{ article.author }}</p>

            <hr>

            {% for comment in article.comments.all %}
            <div class="comment">
              <div class="date">{{ comment.created_date }}</div>
              <strong>{{ comment.author }}</strong>
              <p>{{ comment.text|linebreaks }}</p>
            </div>
            {% empty %}
            <p>No comments here yet :(</p>
            {% endfor %}
          </div>
          <!-- Post A Comment Area -->
          <div class="post-a-comment-area bg-white mb-30 p-30 box-shadow clearfix">
            <!-- Section Title -->
            <div class="section-heading">
              <h5>LEAVE A REPLY</h5>
            </div>
            <!-- Reply Form -->
            <div class="contact-form-area">
              <form action="#" method="post">
                <div class="row">
                  <div class="col-12 col-lg-6">
                    <input type="text" class="form-control comment-section" id="name" placeholder="Your Name*"
                      required />
                  </div>
                  <div class="col-12 col-lg-6">
                    <input type="email" class="form-control comment-section" id="email" placeholder="Your Email*"
                      required />
                  </div>
                  <div class="col-12">
                    <textarea name="message" class="form-control" id="message" cols="30" rows="10"
                      placeholder="Message*" required></textarea>
                  </div>
                  <div class="col-12">
                    <button class="btn mag-btn comment-section" type="submit">
                      Submit Comment
                    </button>
                  </div>
                </div>
              </form>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
</section>


{% endblock %}

my views.py:

from django.shortcuts import render, reverse, get_object_or_404
from django.views import generic
from news.models import Article, Category
from .forms import CommentForm
from django.http import HttpResponseRedirect


class IndexView(generic.ListView):

    template_name = 'news/index.html'
    context_object_name = 'latest_article_list'

    def get_queryset(self):
        return Article.objects.order_by("-pub_date").filter(is_published=True)[:6]


class CategoryView(generic.ListView):

    template_name = 'news/categories.html'
    context_object_name = 'category'

    def get_queryset(self):
        return Article.objects.filter(article_category__category_title="Politics")


class ArticlesView(generic.ListView):
    context_object_name = 'latest_article_list'
    template_name = 'news/articles.html'
    paginate_by = 5

    def get_context_data(self, **kwargs):
        context = super(ArticlesView, self).get_context_data(**kwargs)
        context['categories'] = Category.objects.all()
        return context

    def get_queryset(self):
        category_pk = self.request.GET.get('pk', None)
        if category_pk:
            return Article.objects.filter(article_category__pk=category_pk).order_by("-pub_date")
        return Article.objects.order_by("-pub_date")


def article(request, article_id):

    article = get_object_or_404(Article, pk=article_id)
    context = {'article': article}

    return render(request, 'news/article.html', context)


def add_comment_to_article(request, pk):
    article = get_object_or_404(Article, pk=pk)
    if request.method == "POST":
        form = CommentForm(request.POST)
        if form.is_valid():
            comment = form.save(commit=False)
            comment.post = article
            comment.save()
            return HttpResponseRedirect(reverse('news:article', kwargs={"article_id": article.pk}))
    else:
        form = CommentForm()
    return render(request, 'news/add_comment_to_article.html', {'form': form})

my "all articles" page:

<div class="container">
    {% block articles %}

    <!-- ***************************************** -->
    <div class="category-filter container">
        <ul>
            <li class="categories-title">Categories:</li>
            <hr class="small-line">
            {% for category in categories %}

            <li class="category-list">
                <a href="{% url 'news:articles' %}?pk={{category.id}}">{{ category.category_title }}</a>
            </li>
            {% endfor %}
        </ul>
    </div>
    <!-- ***************************************** -->
    {% show_results latest_article_list %}

    <hr class="hr-style1">
    <h2 class="article-list-title">Article List :</h2>
    <hr class="hr-style2">
    <div class="container list-wrapper">

        {% for article in latest_article_list %}

        <div class="container">
            <div class="well">
                <div class="media">
                    <a class="pull-left" href="{% url 'news:article' article.id %}">
                        <img class="media-object" src="{{ article.article_image.url }}">
                    </a>
                    <div class="media-body">
                        <h4 class="media-heading"><a href="{% url 'news:article' article.id %}">{{ article.title }}</a>
                        </h4>
                        <p class="text-right">{{ article.author }}</p>
                        <p>{{ article.description }}</p>
                        <ul class="list-inline list-unstyled">
                            <li><span><i class="glyphicon glyphicon-calendar"></i> {{ article.pub_date }}
                                </span></li>
                            <li>|</li>
                            <span><i class="glyphicon glyphicon-comment"></i> 2 comments</span>
                            <li>|</li>
                            <li>
                                <span class="glyphicon glyphicon-star"></span>
                                <span class="glyphicon glyphicon-star"></span>
                                <span class="glyphicon glyphicon-star"></span>
                                <span class="glyphicon glyphicon-star"></span>
                                <span class="glyphicon glyphicon-star-empty"></span>
                            </li>
                            <li>|</li>
                            <li>
                                <span><i class="fa fa-facebook-square"></i></span>
                                <span><i class="fa fa-twitter-square"></i></span>
                                <span><i class="fa fa-google-plus-square"></i></span>
                            </li>
                        </ul>
                    </div>
                </div>
            </div>
        </div>
    </div>
    {% endfor %}

Thank you so much for taking the time to read this. Have a good day !

Answer 1

Your changed code wouldn't work at all on the single article page; you would get an AttributeError.

The problem is that you are in your list view you are passing the queryset, latest_article_list , but in the single article view you are passing that single article. You can't filter an article, you can only filter a queryset.

Really it seems that the thing you want to do is to pass a category. There's no reason to pass the latest article list to that template tag; you can just get the articles directly in the tag. But from the single article view you want to get the articles with the same category. So, make the parameter category , and make it optional.

@register.inclusion_tag("news/categories.html")
def show_results(category=None):
    articles = Article.objects.all()
    if category:
        articles = articles.filter(category=category)
    return {'article': article[:3]}

Now from the list view you can just call the tag without arguments:

{% show_results %}

whereas from the single view you can pass the article category:

{% show_results article.category %}