在Django模板中隐藏来自ModelForms的外键字段

Question

Essence in the following. I have a few different Magazine. And AutoForm from template shows all Articles and all Authors for possible selection (not only from current Magazine). How to restrict this choice of author a for article only from the current magazine? Can I do this using only the Template? If not, then how?

models.py

class Magazine(models.Model):
    Name = models.CharField(max_length=200)

class Article(models.Model):
    Name = models.CharField(max_length=200)
    Magazine = models.ForeignKey(Magazine)

class Author(models.Model):
    Name = models.CharField(max_length=200)
    Magazine = models.ForeignKey(Magazine)

class Sets(models.Model):
    Name = models.CharField(max_length=200)
    Magazine = models.ForeignKey(Magazine)
    Aut = models.ManyToManyField(Author, null=True, blank=True)
    Set = models.ForeignKey(Article, null=True, blank=True)

forms.py:

class MagazineForm(ModelForm):
    class Meta:
        model = Magazine
        fields = {'Name'}

class ArticleForm(ModelForm):
    class Meta:
        model = Article
        fields = {'Name'}

class AuthorForm(ModelForm):
    class Meta:
        model = Author
        fields = {'Name'}

class SetsForm(ModelForm):
    class Meta:
        model = Sets
        fields = {'Name', 'Set', 'Aut'}

views.py

def building_details(request, magazine_id):
    sets_form = SetsForm
    args = {}
    args.update(csrf(request))
    args['magazine'] = Magazine.objects.get(id=magazine_id)
    args['article'] = Article.objects.filter(Magazine=magazine_id)
    args['author'] = Author.objects.filter(Magazine=magazine_id)
    args['sets'] = Sets.objects.filter(Magazine=magazine_id)
    args['setform'] = sets_form
    return render_to_response('building.html', args)

Template

<form action='/add/{{ magazine.id }}/' method='post'>
{% csrf_token %}
{{ setform }}
<input type='submit' class='button' value="Добавить">
</form>
</div>

Maybe somewhere in this entry there are errors (I briefly edited, removing not playing a role here, essentially). In General I have everything working right, except that all objects are displayed, instead of only having the current.

Answer 1

Sounds like you are trying to restrict the options in the ForeignKey selector based on some criteria.

This means you need to override some of the details in the forms __init__ method:

class SetsForm(ModelForm):
    class Meta:
        model = Sets
        fields = {'Name', 'Set', 'Aut'}

    def __init__(self, *args, **kwargs):
        articles = Article.objects.filter(Magazine=kwargs.pop('magazine_id'))
        super(SetsForm, self).__init__(*args, **kwargs)
        self.fields['articles'] = forms.ModelChoiceField(
            queryset=articles ,
            label="Articles",
        )

Then call your form like so:

sets_form = SetsForm(magazine_id=magazine_id)

Answer 2

To get authors of articles only in the current magazine:

articles = Article.objects.filter(Magazine=magazine_id)
sets = Sets.objects.filter(Magazine=magazine_id, Set__in=articles)

import itertools
# build a flat list of all Authors in these sets (and call `set` to avoid duplicates)
authors = set(itertools.chain(*[s.Aut.all() for s in sets]))

This would be easier if there were a direct foreign key on Author to Article.

Also, you should follow Django convention by using lowercase field names. This will avoid confusion between fields and models, which use uppercase.