Developing a login page is a crucial aspect of constructing a secure and user-friendly web application. In this post, I will lead you through the steps of crafting a login page utilizing Flask, a prevalent Python web framework that enables us to swiftly and effortlessly construct web applications.
Introduction to Flask
Flask is a micro web framework written in Python. It is lightweight and allows developers to build web applications quickly and with less code compared to other frameworks. Flask follows the model-view-controller (MVC) architectural pattern, making it easy to organize and manage your application.
Before we dive into the process of creating a login page, let’s make sure you have Flask installed on your machine. If not, you can install it by running the following command:
pip install Flask
Creating the Login Page
Now that we have Flask installed, let’s start building our login page. First, we need to create a new Flask application. Create a new Python file and add the following code:
from flask import Flask, render_template, request, redirect, url_for
app = Flask(__name__)
@app.route('/')
def home():
return render_template('index.html')
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'POST':
# Validate the login credentials
username = request.form['username']
password = request.form['password']
# Add your authentication logic here
if username == 'my_username' and password == 'my_password':
return redirect(url_for('dashboard'))
else:
return render_template('login.html', error='Invalid username or password')
return render_template('login.html')
@app.route('/dashboard')
def dashboard():
return 'Welcome to the dashboard!'
if __name__ == '__main__':
app.run(debug=True)
This code sets up a Flask application with three routes: the home route (‘/’) which renders the index.html template, the login route (‘/login’) which handles the login form submission, and the dashboard route (‘/dashboard’) which displays the dashboard page after a successful login.
Next, let’s create the templates for our login and dashboard pages. In your project directory, create a new folder named ‘templates’ and inside it, create two HTML files: ‘index.html’ and ‘login.html’.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>My App</title>
</head>
<body>
<h1>Welcome to My App!</h1>
<p>Please <a href="/login">login</a> to continue.</p>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Login</title>
</head>
<body>
<h2>Login</h2>
{% if error %}
<p style="color: red">{{ error }}</p>
{% endif %}
<form action="/login" method="POST">
<label for="username">Username:</label>
<input type="text" id="username" name="username" required>
<br>
<label for="password">Password:</label>
<input type="password" id="password" name="password" required>
<br>
<input type="submit" value="Login">
</form>
</body>
</html>
The ‘index.html’ template is a simple welcome page with a link to the login page. The ‘login.html’ template contains a login form where users can enter their credentials. If there is an error, it will be displayed at the top of the form.
Conclusion
Creating a login page in Flask is a straightforward process. By following the steps outlined in this article, you can build a secure login system for your web application. Remember to add your own authentication logic to validate user credentials and protect sensitive information.
Flask provides a solid foundation for building web applications with Python. Its simplicity and flexibility make it a popular choice among developers. So go ahead and start building your own login system with Flask!
