from flask_wtf import FlaskForm from wtforms import StringField, SubmitField, ValidationError from wtforms.validators import DataRequired, Length from app import models as m from app.logger import log class BaseBookForm(FlaskForm): label = StringField("Label", [DataRequired(), Length(6, 256)]) about = StringField("About") class CreateBookForm(BaseBookForm): submit = SubmitField("Add new book") class EditBookForm(BaseBookForm): book_id = StringField("User ID", [DataRequired()]) tags = StringField("Tags") submit = SubmitField("Edit book") def validate_label(self, field): label = field.data book_id = self.book_id.data existing_book: m.Book = ( m.Book.query.filter_by( is_deleted=False, label=label, ) .filter(m.Book.id != book_id) .first() ) if existing_book: log( log.WARNING, "Book with label [%s] already exists: [%s]", label, book_id ) raise ValidationError("Book label must be unique!")