In Flask, flash messages are used to display feedback messages to users about the actions they have taken on a website or web application. These messages are typically displayed at the top of the page or in a prominent location to catch the user’s attention. Flash messages are a useful way to provide feedback to users in real-time and can improve the overall user experience of your Flask application.
In this tutorial, we will walk through how to create flash messages in Flask using the pydroid3 IDE, which is a Python IDE that can be used on mobile devices for Flask development.
Step 1: Setting up your Flask project in pydroid3
Before we can create flash messages in our Flask application, we need to set up a project in pydroid3. To do this, open pydroid3 on your mobile device and create a new Python project. Name your project and create a new Python file within the project.
Next, we need to install Flask in our project. To do this, open the terminal in pydroid3 and run the following command:
pip install FlaskStep 2: Creating a Flask application
Now that we have Flask installed in our project, we can start creating our Flask application. In your Python file, import the Flask module and create a new Flask app instance.
from flask import Flask
app = Flask(__name__)Step 3: Creating a route with a flash message
Next, we will create a simple route in our Flask application that displays a flash message. To do this, we will use the flash() function provided by Flask.
from flask import flash, redirect, render_template
@app.route('/')
def index():
flash('This is a flash message!')
return render_template('index.html')In this code snippet, we created a route called index() that displays a flash message using the flash() function. The message we provided as an argument to the flash() function will be displayed to the user when they visit the route.
Step 4: Setting up the secret key
In order for flash messages to work properly in Flask, we need to set up a secret key for our application. This key is used to securely sign and encrypt the flash messages. To do this, add the following line of code to your Flask application:
app.secret_key = 'super_secret_key'Step 5: Displaying flash messages in HTML templates
To display flash messages in our HTML templates, we need to loop through the messages stored in the _flashes session variable. Here’s how you can do this in your HTML template:
<!DOCTYPE html>
<html>
<head>
<title>Flash Messages</title>
</head>
<body>
{% with messages = get_flashed_messages() %}
{% if messages %}
<ul>
{% for message in messages %}
<li>{{ message }}</li>
{% endfor %}
</ul>
{% endif %}
{% endwith %}
</body>
</html>In this code snippet, we used the get_flashed_messages() function provided by Flask to get the flash messages stored in the _flashes session variable. We then looped through the messages and displayed them as list items in an unordered list.
Step 6: Running your Flask application
Now that we have set up our Flask application with flash messages, we can run the application in pydroid3. To do this, add the following code snippet at the bottom of your Python file:
if __name__ == '__main__':
app.run()Then, run your Flask application by clicking the "Run" button in pydroid3. You should see a flash message displayed when you visit the route you created.
In conclusion, flash messages are a great way to provide feedback to users in a Flask application. By following the steps outlined in this tutorial, you can easily create flash messages in your Flask application using pydroid3.
