Flask，WTForms：编辑和创建表单规则不同时出错

Question

I'm using Flask and WTForms in a web app. I have a db.Model, a form and a sqla.ModelView like this:

class Users(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.INTEGER, primary_key=True)
    name = db.Column(db.String, nullable=False)
    last_name = db.Column(db.String, nullable=False)

class UsersForm(form.Form):
    id = fields.IntegerField('Id')
    name = fields.StringField('Name')
    last_name = fields.StringField('Last Name')

class UsersAdmin(sqla.ModelView):
    column_list = ['id', 'name', 'last_name']
    form = UsersForm
    form_create_rules = column_list
    form_edit_rules = ['name', 'last_name']

But it doesn't work because this error:

ValueError: Form <__main__.UsersForm object at 0x7f5039c48710> does not have field name

However, when form_edit_rules is equal to form_create rules, it works perfectly!

Answer 1

I found out on flask-admin github issuelist that form_*_rules only affect how form is displayed, but don't affect the form itself.

Creating an instance of a form in flask-admin is not necessary. I would recommend to have your database take care of the id, as it automatically auto-increments. In my experience, flask-admin doesn't even show the id field.

If you really want to have an editable id field on the create form only, you can make the field readonly on the edit form with the following code:

class UsersAdmin(sqla.ModelView):
    def on_form_prefill(self, form, id):
        form.id.render_kw = {'readonly': True}

    column_list = ['id','name','last_name']
    form = UsersForm