Reverse for 'update_comment' with arguments '('',)' not found. 1 pattern(s) tried: ['comment\\\\/(?P<news_pk>[0-9]+)$']

问题:

I'm coding a news site.Now I'm detailing with the comment post function.And meet the issue says:

Reverse for 'update_comment' with arguments '('',)' not found. 1 pattern(s) tried: ['comment\\/(?P<news_pk>[0-9]+)$'] 

I have tried many ways and times but still can't solve it and I can't find any wrong with my code.And really need your help.

The comment post function is in the news_detail.html. There are two important apps in my project news and operation comment models is under operation

Here is my root urls.py:

path('news', include(('news.urls', 'news'), namespace="news")), path('', include(('operation.urls', 'operation'), namespace="operation")), 

Here is the news/urls.py

path('-<int:news_pk>', newsDetailView, name="news_detail") 

Here is the operation/urls.py:

path('comment/<int:news_pk>', views.update_comment, name="update_comment"), 

Here is the news/view.py

def newsDetailView(request, news_pk):     news = News.objects.get(id=news_pk)     title = news.title     author = news.author_name     add_time = news.add_time     content = news.content     category = news.category     tags = news.tag.annotate(news_count=Count('news'))      all_comments = NewsComments.objects.filter(news=news)     return render(request, "news_detail.html", {         'title': title,         'author': author,         'add_time': add_time,         'content': content,         'tags': tags,         'category': category,         'all_comments': all_comments,     }) 

Here is operation/views.py

def update_comment(request, news_pk):     news = News.objects.get(id=news_pk)     comment_form = CommentForm(request.POST or None)     if request.method == 'POST' and comment_form.is_valid():         if not request.user.is_authenticated:             return render(request, 'login.html', {})         comments = comment_form.cleaned_data.get("comment")         news_comment = NewsComments(user=request.user, comments=comments, news=news)         news_comment.save()          return render(request, "news_detail.html", {             'news_comment': news_comment，             'news'：news         }) 

And here is the news_detail.html:

{% if user.is_authenticated %}  <form method="POST" action="{% url 'operation:update_comment' news.pk %}">{% csrf_token %}                <textarea id="js-pl-textarea" name="comment"></textarea>        <input type="submit" id="js-pl-submit" value="发表评论"></input></form> 

回答1:

You're not passing the news object into the context for news_detail.html. You can simplify the view a lot by just passing news and doing things like {{ news.title }} in the template (instead of {{ title }}):

def newsDetailView(request, news_pk):     news = get_object_or_404(News, id=news_pk)     tags = news.tag.annotate(news_count=Count('news'))     all_comments = NewsComments.objects.filter(news=news)      return render(request, "news_detail.html", {         'news': news,         'tags': tags,         'all_comments': all_comments,     }) 

Now news.pk will work as argument to your {% url ... %} tag. I've also ensured a 404 error is generated if the news object cannot be found (in your code, it would crash).

回答2:

{% url 'some-url-name' arg1=v1 arg2=v2 %} 

ref: https://docs.djangoproject.com/en/2.0/ref/templates/builtins/#url

fixed: Your code is correct. The error hint that:

 arguments '('',)' not found.    arguments '('',)' 

文章来源: Reverse for 'update_comment' with arguments '('',)' not found. 1 pattern(s) tried: ['comment\\\\/(?P[0-9]+)$']