def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def add_user():
    form = AddUserForm()
    if form.validate_on_submit():
        form.save()
        flash(_("User added."), "success")
        return redirect(url_for("management.users"))

    return render_template("management/user_form.html", form=form,
                           title=_("Add User"))