django反向＆＃x27; ＆＃x27;用参数＆＃x27;（＆＃x27;＆＃x27;，）＆＃x27;未找到

Question

使用Django时，我有问题。我试图从我的书中创建Learning_log Web应用程序，并遇到此错误：noreversematch at/edit_entry/8/ 找不到“主题”的“主题”（''，）'找不到。 1个模式尝试：['主题/（？它说这是因为我的edit_entry.html文件中的这一行：p＆gt;＆lt; a href =“ {％url'Learning_logs：topic'topic'topic'topic.id％}” a＆gt;＆lt;/p＆gt;，但我检查了整个项目，找不到原因， 这是我的urls.py：views.py：models.py：forms.py：base.html：topics.html：new_topic.html：new_entry.html：topic.html：edist_entry.htry.html：index.html：index.html

from django.urls import path

from . import views

app_name = 'learning_logs'
urlpatterns = [
    path('', views.index, name='index'),
    path('topics/', views.topics, name='topics'),
    path('topics/<int:topic_id>/', views.topic, name='topic'),
    path('new_topic/', views.new_topic, name='new_topic'),
    path('new_entry/<int:topic_id>/', views.new_entry, name='new_entry'),
    path('edit_entry/<int:entry_id>/', views.edit_entry, name='edit_entry'),
]

是那是

from django.shortcuts import render, redirect
from .models import Topic, Entry
from .forms import TopicForm, EntryForm
def index(request):
    """The home page for Learning Log."""
    return render(request, 'learning_logs/index.html')
def topics(request):
    """Show all topics."""
    topics = Topic.objects.order_by('date_added')
    context = {'topics': topics}
    return render(request, 'learning_logs/topics.html', context)
def topic(request, topic_id):
    """Show a single topic and all its entries."""
    topic = Topic.objects.get(id=topic_id)
    entries = topic.entry_set.order_by('-date_added')
    context = {'topic': topic, 'entries':entries}
    return render(request, 'learning_logs/topic.html', context)
def new_topic(request):
    """Add a new topic."""
    if request.method !='POST':
        form = TopicForm()
    else:
        form = TopicForm(data=request.POST)
        if form.is_valid():
            form.save()
            return redirect('learning_logs:topics')

    context = {'topic': topic, 'form': form}
    return render(request, 'learning_logs/new_entry.html', context)
def edit_entry(request, entry_id):
    """Edit and existing entry."""
    entry = Entry.objects.get(id=entry_id)
    topic = entry.topic

    if request.method !='POST':
        form = EntryForm(instance=entry)
    else:
        form = EntryForm(instance=entry, data=request.POST)
        if form.is_valid():
            form.save()
            return redirect('learning_logs:topic', topic_id=topic.id)

   context = {'entry': entry, 'topic': topic, 'form': form}
   return render(request, 'learning_logs/edit_entry.html')

：

from django.db import models

class Topic(models.Model):
    """A topic the user is learning about."""
    text = models.CharField(max_length=200)
    date_added = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        """Return a string representation of the model."""
        return self.text

class Entry(models.Model):
    """Something specific about a learned topic."""
    topic = models.ForeignKey(Topic, on_delete=models.CASCADE)
    text = models.TextField()
    date_added = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name_plural = 'entries'

    def __str__(self):
        """Return a string representation of the model."""
        return f"{self.text[:50]}..."

那

from django import forms

from .models import Topic, Entry

class TopicForm(forms.ModelForm):
    class Meta:
        model = Topic
        fields = ['text']
        labels = {'text': ''}

class EntryForm(forms.ModelForm):
    class Meta:
        model = Entry
        fields = ['text']
        labels = {'text': ''}
        widgets = {'text': forms.Textarea(attrs={'cols': 80})}

是那是那是

<p>
  <a href="{% url 'learning_logs:index' %}">Learning Log</a>
  <a href="{% url 'learning_logs:topics' %}">Topics</a>
</p>

{% block content %}{% endblock content %}

那

{% extends "learning_logs/base.html" %}

{% block content %}

  <p>Topics</p>

  <ul>
    {% for topic in topics %}
      <li>
        <a href="{% url 'learning_logs:topic' topic.id %}">{{ topic }}</a>
      </li>
    {% empty %}
      <li>No topics have been added yet.</li>
    {% endfor %}
  </ul>

  <a href="{% url 'learning_logs:new_topic' %}">Add a new topic</a>

{% endblock content %}

是

{% extends "learning_logs/base.html" %}

{% block content %}
  <p>Add a new topic:</p>

  <form action="{% url 'learning_logs:new_topic' %}" method='post'>
    {% csrf_token %}
    {{ form.as_p }}
    <button name="submit">Add topic</button>
  </form>

{% endblock content %}

那

{% extends "learning_logs/base.html" %}

{% block content %}

  <p><a href="{% url 'learning_logs:topic' topic.id %}">{{ topic }}</a></p>

  <p>Add a new entry:</p>
  <form action="{% url 'learning_logs:new_entry' topic.id %}" method='post'>
    {% csrf_token %}
    {{ form.as_p }}
    <button name='submit'>Add entry</button>
  </form>

{% endblock content %}

是

{% extends "learning_logs/base.html" %}

{% block content %}

  <p>Topic: {{ topic }}</p>

  <p>Entries:</p>
  <p>
    <a href="{% url 'learning_logs:new_entry' topic.id %}">Add new entry</a>
  <ul>
    {% for entry in entries %}
      <li>
        <p>{{ entry.date_added|date:'M d, Y H:i' }}</p>
        <p>{{ entry.text|linebreaks }}</p>
        <p>
          <a href="{% url 'learning_logs:edit_entry' entry.id %}">Edit entry</a>
        </p>
      </li>
    {% empty %}
      <li>There are no entries for this topic yet.</li>
    {% endfor %}
  </ul>

{% endblock content %}

那

{% extends "learning_logs/base.html" %}

{% block content %}

  <p><a href="{% url 'learning_logs:topic' topic.id %}">{{ topic }}</a></p>

  <p>Edit entry</p>

  <form action="{% url 'learning_logs:edit_entry' entry.id %}" method='post'>
    {% csrf_token %}
    {{ form.as_p }}
    <button name="submit">Save changes</button>
  </form>

{% endblock content %}

那

{% extends "learning_logs/base.html" %}

{% block content %}
  <p>Learning Log helps you keep track of what you've learned.</p>
{% endblock content %}

是那是那样。从字面上看，我检查过的所有内容，我似乎找不到错误，请帮助我找到错误并修复它。

Answer 1

在views.py中，在edit_entry函数上，将上下文传递到渲染方法。

在edit_entry函数的最后一行中渲染方法。

def edit_entry(request, entry_id):
    """Edit and existing entry."""
    entry = Entry.objects.get(id=entry_id)
    topic = entry.topic

    if request.method !='POST':
        form = EntryForm(instance=entry)
    else:
        form = EntryForm(instance=entry, data=request.POST)
        if form.is_valid():
            form.save()
            return redirect('learning_logs:topic', topic_id=topic.id)

   context = {'entry': entry, 'topic': topic, 'form': form}
   return render(request, 'learning_logs/edit_entry.html')

通过添加上下文来更正最后一行，如下所示。您可以使用entry，主题和form在上下文中定义的 HTML模板。

   return render(request, 'learning_logs/edit_entry.html', context)