Скачать или смотреть Solving the Django BMI Calculator Not Showing Results Issue

Discover how to fix the `Django BMI calculator not showing results` problem with easy-to-follow steps and best practices for building your Django applications.
---
This video is based on the question https://stackoverflow.com/q/77909949/ asked by the user 'Piotr' ( https://stackoverflow.com/u/23323207/ ) and on the answer https://stackoverflow.com/a/77910781/ provided by the user 'McPherson' ( https://stackoverflow.com/u/16774936/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Django BMI calculator not showing results

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Issue: Django BMI Calculator Not Responding

Building a BMI calculator with Django can be a rewarding experience, but it can also lead to confusion when things don’t appear to work as expected. One common problem many developers encounter is their application failing to show results after pressing the calculate button. In this guide, we will address this issue step-by-step, so that you can get back on track with your BMI calculator project.

Overview of the Problem

When submitting the form in your Django app, you're expected to see the calculated BMI based on the inputs for weight and height. However, the app does not display any results after the button is clicked. The root of this problem often lies in missed HTML tags and improper handling of forms in the Django view.

Diagnosing the Problem

Let's break down the code snippets provided to identify the issues:

1. Missing Form Method in HTML

In the HTML template for your calculator, ensure that you have included the correct opening tag for your form, specifically:

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

Without this, the browser does not know how to submit the data when the button is clicked, resulting in no output.

2. Managing Form State in Views

In your views.py, when the form is valid and you calculate the BMI, you are currently returning the bound form, which includes all the previous user inputs. Instead of keeping the old instance, you should create a new instance of the form after processing valid input. Here’s how:

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

Fixing the Issues

To ensure the app displays results after pressing the calculate button, follow these steps:

Step-by-Step Instructions

Modify Your HTML:
Add the correct form method:

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

Update Your Views:
Change the view logic to re-instantiate the form after calculating the BMI:

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

Conclusion: Completing Your BMI Calculator

By ensuring you have the proper form method in your HTML and correctly handling the form state in your Django views, you will be able to see the results of your BMI calculation. Building applications in Django may come with its challenges, but understanding the framework and debugging effectively will make the process much smoother.

Now, you can successfully calculate BMI using your Django application!