Flask flash with categories

flash.css

.flash-message {
  border: 0;
  color: #ffffff;
  margin-bottom: 0;
  position: fixed;
  width: 100%;
  top: 0;
  left: 0;
  z-index: 100000;
  border-radius: 0;
  text-align: center;
  display: none;
  padding: 0;
  height: 50px;
  line-height: 50px;
}
.error {
    background-color: #e51c23;
}
.success {
  background-color: #4caf50;
}
.warning {
  background-color: #ff9800;
}
.info {
  background-color: #9c27b0;
}

flash.js

(function () {
    "use strict";

    // Flash message
    setTimeout(showFlash, 200);
    setTimeout(hideFlash, 2000);

    /**
     * Show flash message.
     */
    function showFlash() {
        $('.flash-message').slideDown('fast');
    }

    /**
     * Hide flash message.
     */
    function hideFlash() {
        $('.flash-message').slideUp('fast');
    }
})();

flash.py

    @classmethod
    def create(cls,**kwargs):
        c = cls(**kwargs)
        db.session.add(c)
        try:
            db.session.commit()
            flash(u'Враг народа успешно создан!', 'success')
        except IntegrityError:
            db.session.rollback()
            flash(u'Не удалось создать врага народа!' + u' IntegrityError', 'error')
        except InterfaceError:
            db.session.rollback()
            flash(u'Не удалось создать врага народа!' + u' InterfaceError', 'error')
        return c

This is an example of using a dynamic Flask Flash with categories, together with the classmethod for SQLAlchemy