我有一个模型Jar
,它有一个crate
属性——ForeignKey
一个Crate
模型。该Crate
模型有一个capacity
属性(它可以容纳的罐子的数量)和一个jars
属性(它当前容纳的罐子的数量),它是这一行: return self.jar_set.filter(is_active=True).count()
.
我有一个管理操作,可以将多个罐子移动到一个新的板条箱中。它使用中间页面来选择目标板条箱。现在所有板条箱都列在下拉列表中,但我想将列出的板条箱限制为只有那些有空间容纳所选罐子数量的板条箱。如何?
这是来自的管理操作admin.py
:
class MoveMultipleJarsForm(forms.Form):
# This needs to somehow be restricted to those crates that have room
dest = forms.ModelChoiceField(queryset=Crate.objects.all().order_by('number'))
def move_multiple_jars(self, request, queryset):
form = None
if 'apply' in request.POST:
form = self.MoveMultipleJarsForm(request.POST)
if form.is_valid():
dest = form.cleaned_data['dest']
count = 0
for jar in queryset:
jar.crate = dest
jar.save()
count += 1
plural = ''
if count != 1:
plural = 's'
self.message_user(request, "Successfully moved %d jar%s to %s" % (count, plural, dest))
return HttpResponseRedirect(request.get_full_path())
if not form:
form = self.MoveMultipleJarsForm()
return render(request, 'admin/move_multiple_jars.djhtml', {
'jars': queryset,
'move_multiple_jars_form': form,
})
move_multiple_jars.short_description = "Move multiple jars to new crate"