def home():
form = UserForm(request.form)
if request.method == 'POST' and form.validate():
user = User(username=form.data.get('username'))
form.populate_obj(user)
try:
ss.add(db.session, user)
except IntegrityError:
db.session.rollback()
form.username.errors.append('Username already exists!')
else:
return redirect(url_for('show_users'))
return render_template('welcome.html', form=form)
def add_user(username):
user = User(username=username)
try:
user = ss.add(db.session, user)
except IntegrityError:
# Always issue a rollback when a transaction fails
db.session.rollback()
return 'Username {} already exists!'.format(username)
return 'Hello world, {}'.format(user.username)