admin_forms.py

class CategoryForm(BaseForm):
    name = TextField("Category Name: ")
    description = TextAreaField("Category description: ")

    # child = Select2Field("ChildCats: ", coerce=int)
    # parent_id = Select2TagsField("ChildCats: ", )
    parent_id = SelectMultipleField("ChildCats: ", coerce=int)

admin_view.py

class CategoryModelView(View):
    column_exclude_list = ('master_key', 'IV', 'test_passphrase')
    form_excluded_columns = ('master_key', 'IV', 'test_passphrase')
    edit_form = CategoryForm
    # can_create = False

    # def edit_form(self, obj=None):
    #     assert False
    #     form = self.form


    def edit_form(self, obj=None):
        form = CategoryForm(obj=obj)
        form.parent_id.choices = [
                (p.id, p.name) 
            for p in Category.query.filter(
                Category.parent_id == obj.id
            ).all()
        ]
        # assert False
        form.parent_id.data = [ p.id for p in obj.child ]
        # import pdb; pdb.set_trace()
        return form

    def on_model_change(self, form, model):
        assert False
        print 12312312312312312
        pass

    def after_model_change(self, form, model, is_created):
        print 11111111111111111

    def __init__(self, session, **kwargs):
        super(CategoryModelView, self).__init__(Category, session, **kwargs)

models.py

class Category(db.Model):
    __tablename__ = "categories"
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.Unicode(255), unique=False)
    description = db.Column(db.Text, )

    parent_id = db.Column(db.Integer, db.ForeignKey('categories.id'), default=0)
    child     = db.relationship("Category", 
        remote_side=[id],
        # backref=db.backref('children'),
        # backref='children',
        backref=db.backref('children', lazy='dynamic'),
        )

    master_key = db.Column(db.Binary(), )
    IV = db.Column(db.Binary(), ) 
    test_passphrase = db.Column(db.String(), )

    passwords = db.relationship("Password",
        backref='passwords',
        )

    def __init__(self, **kwargs):
        super(Category, self).__init__(**kwargs)

    def __repr__(self):
        return u"[Category: %s]" % self.name

    def __unicode__(self):
        return u"[Category: %s]" % self.name