我想要做的是让人们通过在字符域中书写来标记帖子,用“,”分隔标签。
现在这是我的模型(只是我们关心的部分)
class Tag(models.Model):
name = models.CharField(max_length=100, default='')
def __unicode__(self):
return "%s" % (self.name)
class Post(models.Model):
.....
tags = models.ManyToManyField(Tag,blank=True, null=True)
然后我有一个表格
class PostForm(ModelForm):
...
tags = forms.CharField(label=(u'Tags '))
class Meta:
model = Publication
def __init__(self, *args, **kwargs):
self.helper = FormHelper()
self.helper.form_method = 'post'
self.helper.add_input(Submit('submit', 'Invia'))
self.helper.form_class = 'form-horizontal'
super(PostForm, self).__init__(*args, **kwargs)
然后我有我的 createView,我覆盖了 form_valid 方法来进行字符串解析
class PostAdd(CreateView):
template_name = 'form.html'
form_class = PostForm
success_url='/'
def form_valid(self, form):
pub = form.save(commit=False)
pub.tags=None
pub.save()
tags=str(self.request.POST.get('tags'))
tags = tags.split(',')
tl=[]
for tag in tags:
tl.append(Tag.objects.get_or_create(name=tag))
pub.tags.add(tl)
form.save_m2m()
return HttpResponseRedirect(self.get_success_url())
我所做的是使用 commit=False 保存表单以更改标签的值。我尝试使用None
or[]
但在所有情况下,我返回的是pub.tags=None
分配行中的错误:
'Post' instance needs to have a primary key value before a many-to-many relationship can be used.