# here are some suggestions to improve the code:
# - Add input validation to prevent malicious input from being processed by the server. You can use a library like flask-wtf to validate user input and sanitize it before processing.
# - Use environment variables to store sensitive information such as database credentials, API keys, and other secrets. This will prevent the information from being hard-coded in the code and exposed in case of a security breach.
# - Implement error handling to provide meaningful error messages to the user in case of errors. You can use the @app.errorhandler() decorator to handle exceptions and return an error response.
import os
from flask import Flask, render_template_string
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import DataRequired, Length, Email
from markupsafe import escape
app = Flask(__name__)
# SECURITY: Load secret key from environment variable instead of hardcoding
app.config['SECRET_KEY'] = os.environ.get('FLASK_SECRET_KEY', os.urandom(32))
class HelloForm(FlaskForm):
name = StringField('Name', validators=[DataRequired(), Length(min=3)])
email = StringField('Email', validators=[DataRequired(), Email()])
submit = SubmitField('Submit')
# Form template with proper CSRF protection and escaping
FORM_TEMPLATE = '''
Hello Form
'''
@app.route('/', methods=['GET', 'POST'])
def hello():
form = HelloForm()
if form.validate_on_submit():
# SECURITY: Use escape() to prevent XSS attacks
safe_name = escape(form.name.data)
safe_email = escape(form.email.data)
return f'Hello, {safe_name} ({safe_email})!'
# SECURITY: Use Flask's render_template_string for proper escaping
return render_template_string(FORM_TEMPLATE, form=form)
@app.errorhandler(400)
def bad_request(error):
return 'Bad request', 400
if __name__ == '__main__':
app.run()