Скачать или смотреть How to Call a Python Function with Parameters in Flask Using a Button

Learn how to effectively trigger a Python function with parameters in Flask when a button is clicked. Improve your web app's notification system with practical examples!
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Triggering Python Functions in Flask Using Buttons

Creating interactive web applications often requires users to perform actions with just a click of a button. In this guide, we’ll tackle a common scenario in Flask applications: calling a Python function with parameters when a button is clicked. This technique can be particularly useful, for example, when sending notifications to users on your website.

The Problem

Imagine you're working on a notification system for your Flask application, where you need to send a notification to users based on certain triggers. You have a function defined in your views.py file that sends notifications. Here’s a simplified version of what you might have:

[[See Video to Reveal this Text or Code Snippet]]

The next step is to call this function effectively when a user presses a button, providing necessary parameters such as the username of the recipient and the type of notification.

The Initial Approach

You might initially consider using the following HTML code for your button:

[[See Video to Reveal this Text or Code Snippet]]

However, using Flask’s url_for() directly here won’t work as expected. This is because url_for() generates URLs for specified routes and doesn't handle Python code as parameters.

The Solution: Using URL Parameters

Instead of trying to pass parameters directly, you can structure your route to accept URL parameters. Here’s how you can modify your Flask route and HTML accordingly:

Revised Flask Route

Update your route to accept the user and type as part of the URL:

[[See Video to Reveal this Text or Code Snippet]]

Updated HTML Button and JavaScript Function

Next, change your button to call a JavaScript function that constructs the URL dynamically:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Solution

Using URL Parameters: The updated route captures the username and notification type directly from the URL, allowing your function to use these parameters efficiently.

JavaScript Function: The btnOnClick function dynamically constructs the URL using template literals, making it easy to navigate to your Flask route with the specific user data embedded in the URL.

Readability and Maintainability: This method offers clarity both in your HTML and back-end code, making future updates easier as you can see exactly what parameters are being passed.

Conclusion

Incorporating user-triggered actions in your Flask application enhances interactivity and responsiveness. By structuring your routes to accept URL parameters and using JavaScript to facilitate navigation, you can easily bind button clicks to Python functions, streamlining the workflow of your web application.

Now you're equipped with a foundational technique to enhance the functionality of your notifications system in Flask. Happy coding!