Integrating the React Frontend with the Flask Backend

This chapter represents a critical point in our quest to build a full stack web application. In this chapter, you will be introduced to a set of instructions on how to connect a Flask web server to a React frontend. You will learn how to pass form entries from the React frontend to the Flask backend. And after this integration, you can be officially called a full stack web developer.

React web applications usually have a sleek look and feel and are regarded as the Rolls-Royce of modern frontend web application applications. React has an intuitive user-interface-focused library, capable of powering production-grade web and mobile applications with ease.

The robust React ecosystem coupled with React’s tools and libraries facilitates end-to-end web development. When you combine React’s incredible component-based design pattern with a minimalist lightweight Flask framework, you get a rich web application that can...

Technical requirements

The complete code for this chapter is available on GitHub at: https://github.com/PacktPublishing/Full-Stack-Flask-and-React/tree/main/Chapter10.

The Bizza application structure

In this section, we will go deeper into the structure of the application we will build in this book. As stated previously, we will name the fictitious web app Bizza, a conference event web application.

This Bizza web app will serve as the digital hub for a conference event for speakers from the information technology industry, providing a myriad of features and functionalities that enhance the speakers’ and attendees’ overall experience. Let’s delve into the Bizza application structure.

Application overview

Bizza is a fictitious data-driven event application that allows subject experts in the information technology industry to share their insights and experiences, providing valuable knowledge to enhance event attendees’ skills.

Bizza lets you see a list of speakers and workshop schedules with details. This site lets users register and browse for a workshop. Essentially, the application will have the following functionalities...

Configuring the React frontend for API consumption

In this section, you will configure the frontend React app to communicate with the backend Flask server by setting up a proxy in React to consume the API from the Flask server.

In order to configure the React proxy for API consumption, you will need to update the proxy field in the package.json file of the frontend React app. The proxy field allows you to specify a URL that will be used as the base for all API requests made from the React app.

Let’s update the package.json file:

1. Open the package.json file in the project directory using a text editor, and then add a proxy field to the package.json file and set it to the URL of your Flask server:

   {  "name": "bizza",  "version": "0.1.0",  "proxy": "http://localhost:5000"}

2. Next, you will need to make HTTP requests to the Flask server from the React frontend. We will use the...

Making Flask backend-ready

In the Setting up the development environment with Flask section of Chapter 1, Getting Full Stack Ready with React and Flask, we set up the development environment for the Flask server. Ensure your virtual environment is activated. You can do so by running the following commands:

• For Mac/Linux:

  source venv/bin/activate

• For Windows:

  Venv/Scripts/activate

Your virtual environment should now be activated, and your terminal prompt should be prefixed with the name of the virtual environment (for example, (venv) $).

Next, let’s dive straight into defining an event registration route, with its function as part of the requirements for Bizza application model.

Let’s add a model to handle registrations for event attendees. You will later use it to accept requests from the React frontend in the next section, where we will handle form inputs in React and Flask.

The app.py file in the root directory of your application is still...

Handling forms in React and Flask

Handling forms in a React frontend and a Flask backend is a common pattern in web development. In this pattern, the React frontend sends HTTP requests to the Flask backend to submit or retrieve form data.

On the React frontend side, you can use a form component to render a form and handle form submissions. You can use controlled components, such as input, textarea, and select, to control the form values and update the component state as a user inputs data.

When the user submits the form, you can use an event handler to prevent the default form submission behavior and send an HTTP request to the Flask backend using a library such as Axios. In this section, we will work with the Axios library.

On the Flask backend side, you can define a route to handle the HTTP request and retrieve the form data from the request object. You can then process the form data and return a response to the frontend.

The EventRegistration component provides a simple...

Troubleshooting tips for the React frontend and the Flask backend

Integrating a React frontend with a Flask backend can be a powerful combination to build dynamic and scalable web applications. However, like any integration, it can come with its own set of unavoidable challenges. Troubleshooting issues that arise during the React-Flask integration process requires a systematic approach to identify and resolve problems effectively.

This section will discuss how you can resolve some of the issues that you may encounter while integrating the frontend with the backend. By following these tips, you will be able to diagnose and resolve common problems that may arise during the development and deployment of your application.

Let’s dive into the troubleshooting tips for the React frontend and the Flask backend integration:

• Verifying the Flask setup:
  • Ensure that Flask is properly configured and running on the server
  • Check the Flask server console for any error messages or...

Summary

In this chapter, we discussed extensively the application code structure and a few key steps required to integrate a React frontend with a Flask backend. First, you will need to set up the frontend to communicate with the backend, using an HTTP client library, and handle forms and user input.

Then, you will need to set up the Flask backend with the necessary routes and functions to handle the requests from the frontend and process the form data. Finally, you will need to test the entire application to ensure that it works correctly and as expected.

With these steps, you can successfully integrate a React frontend with a Flask backend for your web application. In the next chapter, we will scale up the React-Flask interactions by creating more tables. These tables will have relationships, and we will be able to fetch and display data.