引用字段和Wtforms

Question

我在使用 mongoengine 和 wtforms 的时候遇到了连接问题。

我想给 User class 赋予权限，使用的是 Role class，但是我无法把 Role class 的外键关联到 User class 上。

这是我的代码：

# On class File
from mongoengine import Document, StringField, ReferenceField

class User(Document):
    username = StringField(unique=True)
    password = StringField()
    role = RefrenceField(Role, default=Role.objects.get(num=3))

class Role(Document):
    num = IntField()
    name = StringField()

# On form File 
from wtforms import Form, StringField, SelectField

class UserEditForm(Form):
    username = StringField(u'Username', [validators.required()]
    role = SelectField(u'Role', [validators.required()], choices=[(r.id, r.name) for r in Role.objects])

在保存的时候，我收到了这个错误信息：

ValidationError: ValidationError (User:53a14fb0cdc4674abf452f2d) (A ReferenceField only accepts DBRef or documents: ['role'])

我尝试把 r.id 替换成 r 和 r._object_key()，但是没有任何效果。

谢谢，

Answer 1

我找到答案了：SelectField 对于 ReferenceField 返回的类型不太对。

所以这是我新的代码：

# form File
class UserEditForm(Form):
  username = StringField(u'Username', [validators.required()])
  role = SelectField(u'Role', [validators.required()], choices=[(r.num, r.name) for r in Role.objects], coerce=int)

# Controller class
class EditUser(MethodView):
  def get_context(self, id):
    usr = User.objects.get(id=id)
    form = UserEditForm(request.form, usr)
    return {"usr": usr, "form": form}
  def post(self, id):
   context = self.get_context(id)
   form = context.get("form")
   if form.validate():
     usr = context.get("usr")
     form.populate_obj(usr)
     usr.role = Role.objects.get(num=form.role.data)
     usr.save()
     return redirect("/user_edit/" + id)
   return response("form error validation")

祝你有美好的一天