CODEWITHSUNDEEP
pythonflask
iwantocry199283
iwantocry199283

Reputation: 1

Python flask, registration page validation issue

I am trying to create a login system for my website. If a user makes an account with an already existing account the DB crashes and runs into an error. My problem is I don't know how I can make it so that it checks if that username has already been taken and flashes an error message if that name is already taken.

I am unsure what to add after if newUser:, I'm new to Flask/Python so any help would go a long way.

Thank you.

@app.route('/signup', methods=['GET', 'POST'])
def signup():
    form = SignupForm()
    if form.validate_on_submit():
        hashed_password = generate_password_hash(form.password.data, method='sha256')

        db.session.add(newUser)
        db.session.commit()

        return render_template('index..html')

    return render_template('signup.html', form=form)

Upvotes: 0

Views: 85

Answers (1)

Dani G
Dani G

Reputation: 1242

You need to query the DB before creating a new user:

@app.route('/signup', methods=['GET', 'POST'])
def signup():
    form = SignupForm()
    if form.validate_on_submit():
        hashed_password = generate_password_hash(form.password.data, method='sha256')

        user = db.session.query(User).filter_by(username=form.username.data).scalar()
        if user:
            flash('Please choose another username')
        else:
            newUser = User(username=form.username.data)
            db.session.add(newUser)
        db.session.commit()


        return render_template('index.html')

     return render_template('signup.html', form=form)

Look at this line in the code:

user = db.session.query(User).filter_by(username=form.username.data).scalar()

Upvotes: 1

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