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我在构建自定义表单（仅默认模型表单）方面没有太多经验，我在这里寻求帮助。我正在尝试构建一个从用户那里获取“feed_url”的表单，如果它已经存在，只需将引用添加到 UserFeed 模型中。如果它不存在，则应将其添加到 Feed 模型中，并在 UserFeed 模型中引用它。

楷模

class Category(models.Model):
    name = models.CharField(unique=False, max_length=64)
    user = models.ForeignKey(User)
    slug = AutoSlugField(populate_from='name', always_update='True', unique_with='user')


    def __unicode__(self):
        return self.name

    class Meta:
        ordering = ('name',)


class Feed(models.Model):
    feed_url = models.URLField(unique=True)

    def __unicode__(self):
        return self.feed_url


class UserFeed(models.Model):
    feed = models.ForeignKey(Feed)
    title = models.CharField(max_length=64)
    category = models.ForeignKey(Category)
    user = models.ForeignKey(User)
    slug = AutoSlugField(populate_from='title', always_update='True', unique_with='user')

    def __unicode__(self):
        return self.title

    class Meta:
        ordering = ('title',)

形式

class UserFeedForm(forms.Form):
    feed_url = forms.URLField()
    title = forms.CharField(max_length=64)
    category = forms.ModelChoiceField(Category)
    user = forms.HiddenInput()

意见

def addfeed(request):
    categories = Category.objects.filter(user=request.user)
    feeds = Feed.objects.all()
    if request.method == 'POST':
        form = UserFeedForm(request.POST)
        form.fields['category'].queryset = categories
        if form.is_valid():
            feed = form.save(commit=False)
            if form.fields['feed_url'] in feeds:
                ##### add to Feed object and add reference to UserFeed object
                feed.user = request.user
                feed.save()
            else:
                ##### get id from Feed object and add reference to UserFeed object
                feed.user = request.user
                feed.save()
            return HttpResponseRedirect("/reader/manage")
    else:
        form = UserFeedForm()
        form.fields['category'].queryset = categories
    context = {'form': form,}
    return expand_context_and_render(request, context, 'reader/form.html')

有人可以指出我正确的方向吗？谢谢

更新 现在我更新了我的视图和表单如下：

形式

class UserFeedForm(forms.ModelForm):
    feed = forms.URLField()
    title = forms.CharField(max_length=64)
    category = forms.ModelChoiceField(Category)
    user = forms.HiddenInput()

    class Meta:
        model = UserFeed
        fields = ['feed', 'title', 'category']

意见

def addfeed(request):
    categories = Category.objects.filter(user=request.user)
    feeds = Feed.objects.all()
    if request.method == 'POST':
        form = UserFeedForm(request.POST)
        form.fields['category'].queryset = categories
        if form.is_valid():
            feed = form.cleaned_data.get('feed')
            if feed in feeds:
                ##### get id from Feed and add reference to UserFeed
                existing_feed = Feed.objects.get(feed_url=feed)
                form.feed = existing_feed.id
                form.user = request.user
                form.save(commit=True)
            else:
                ##### add to Feed object and then add reference to UserFeed object
                Feed.object.create(feed_url=feed)
                existing_feed = Feed.objects.get(feed_url=feed)
                form.feed = existing_feed.id
                form.user = request.user
                form.save(commit=True)
            return HttpResponseRedirect("/reader/manage")
    else:
        form = UserFeedForm()
        form.fields['category'].queryset = categories
    context = {'page_title': page_title,
               'form': form,
               }
    return expand_context_and_render(request, context, 'reader/form.html')

我想我越来越近了，但它仍然无法工作，给我这个错误：“无法分配“u' http://feeds.bbci.co.uk/news/rss.xml '”：“UserFeed.feed " 必须是一个 "Feed" 实例。"

知道如何解决这个问题吗？谢谢

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3 回答 3

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尝试查看这个问题，以及文档中的内联表单集。

此外，在您的 UserFieldForm 中，feed被定义为URLField. 所以在你看来，在这一行：

feed = form.get_cleaned_data.get('feed')

您的 feed 变量只是一个字符串，实际上并不是 Feed 对象。这是您的错误可能发生的地方？那是inline formsets可以帮助你的地方。此外，这一行也使您的if feed in feeds:陈述没有实际意义，因为feed它只是一个字符串，而feeds它是您所有 Feed 实例的查询集。我认为这会导致您的观点总是被else阻止？

我自己是 Django 的新手，但我希望这对你有所帮助。

于 2013-11-04T06:07:59.630 回答
0

您正在寻找的逻辑是：

  1. 检查提要是否存在。
  2. 如果存在，获取它。
  3. 如果它没有创建新的提要。
  4. 将提要与UserFeed对象相关联。

该get_or_create方法执行第 1-3 部分，因此您需要以下内容：

if form.is_valid():
    obj = form.save(commit=False)
    feed = form.cleaned_data.get('feed')
    feed_obj, created = Feed.objects.get_or_create(feed_url=feed)
    obj.feed = feed_obj
    obj.save()
    return HttpResponseRedirect("/reader/manage")
于 2013-11-04T06:14:09.457 回答
0

我终于让它像这样工作：

形式

class UserFeedForm(forms.Form):
    feed = forms.URLField()
    title = forms.CharField(max_length=64)
    category = forms.ModelChoiceField(Category)
    user = forms.HiddenInput()

    class Meta:
        model = UserFeed
        fields = ['feed', 'title', 'category']

意见

def addfeed(request):
    user = request.user
    categories = Category.objects.filter(user=request.user)
    if request.method == 'POST':
        form = UserFeedForm(request.POST)
        form.fields['category'].queryset = categories
        if form.is_valid():
            feed = form.cleaned_data['feed']
            category = form.cleaned_data['category']
            title = form.cleaned_data['title']
            feed_obj, created = Feed.objects.get_or_create(feed_url=feed)
            obj = UserFeed(feed=feed_obj, title=title, category=category, user=user)
            obj.save()
        return HttpResponseRedirect("/reader/manage")
    else:
        form = UserFeedForm()
        form.fields['category'].queryset = categories
    context = {'page_title': page_title,
               'form': form,
               }
    return expand_context_and_render(request, context, 'reader/form.html')

以下答案中的两个提示都为我指明了正确的方向。谢谢 ！

于 2013-11-06T22:21:42.393 回答