Adventures in Machine Learning

Streamlining Web Development with ReactJS Flask and Gulp

Introduction to ReactJS and Flask Framework

In today’s technology-driven world, web applications play a vital role in everyday life. Building a web application requires a combination of front-end and back-end programming skills.

ReactJS and Flask are two popular technologies that are used to create web applications. In this article, we will take a closer look at what ReactJS and Flask are, how they work together, and how to build a basic web application using these technologies.

ReactJS as a JavaScript UI library

ReactJS is a JavaScript library for building user interfaces. It was originally created by Facebook and is used by many popular websites such as Netflix, Airbnb, and Instagram.

What makes ReactJS different from other JavaScript frameworks such as AngularJS and Vue.js is its ability to build complex user interfaces using a component-based architecture. Components in ReactJS are reusable pieces of code that can be combined to create more complex user interfaces.

When a component is updated, ReactJS will efficiently re-render the components that need to be updated without reloading the entire page. This makes ReactJS an excellent choice for building large-scale web applications.

Flask framework as the back-end language

Flask is a micro web framework written in Python. It is easy to use, lightweight, and flexible.

Flask is ideal for building small to medium sized web applications that require a robust back-end. Flask offers a variety of extensions that provide additional functionality such as database integration, user authentication, and RESTful API development.

Flask is often paired with a front-end framework such as ReactJS to create dynamic web applications. Flask provides the back-end logic for handling requests and responding with the appropriate data, while ReactJS handles the front-end presentation of the data.

Building a basic web application

To illustrate how ReactJS and Flask work together, let’s build a basic web application that retrieves data from a Flask API and displays it using ReactJS. Step 1: Set up the back-end Flask API

First, we need to create a Flask API that will provide the data to our ReactJS application.

Create a new Python file called app.py and add the following code:

from flask import Flask, jsonify

app = Flask(__name__)

@app.route(‘/api/data’)

def get_data():

data = {‘message’: ‘Hello, world!’}

return jsonify(data)

if __name__ == ‘__main__’:

app.run()

This code sets up a Flask API with a single route called /api/data. When this endpoint is called, it returns a JSON object with a message property set to “Hello, world!”.

Step 2: Set up the front-end ReactJS application

Next, we need to create a ReactJS application that will retrieve the data from our Flask API and display it. Create a new directory called frontend and run the following commands:

cd frontend

npx create-react-app my-app

This will create a new ReactJS application called my-app in the frontend directory. Change into the my-app directory and add the following code to the src/App.js file:

import React, { useState, useEffect } from ‘react’;

function App() {

const [data, setData] = useState({});

useEffect(() => {

fetch(‘/api/data’)

.then(res => res.json())

.then(data => setData(data));

}, []);

return (

{data.message}

);

}

export default App;

This code creates a new ReactJS component called App that retrieves the data from our Flask API using the fetch function.

The retrieved data is stored in the state using the useState hook. The retrieved data is then displayed on the page using the returned HTML.

Step 3: Run the application

To run the application, open two terminal windows: one for the Flask API and one for the ReactJS application. In the first terminal window, run the following command:

python app.py

This will start the Flask API running on http://localhost:5000/.

In the second terminal window, go to the frontend/my-app directory and run the following command:

npm start

This will start the ReactJS application running on http://localhost:3000/. If everything is set up correctly, you should see the message “Hello, world!” displayed on the page.

Creating a Dynamic Search tool using React

In the previous section, we built a basic web application that retrieves data from a Flask API and displays it using ReactJS. In this section, we will take things a step further and create a dynamic search tool that filters the displayed data based on user input.

Step 1: Set up the back-end Flask API

In this example, we will be using a sample dataset of books in JSON format. You can download a sample dataset from here.

Save the file as books.json in a new directory called data. Next, we need to create a Flask API that will provide the data to our ReactJS application.

Create a new Python file called app.py and add the following code:

from flask import Flask, jsonify, request

import json

app = Flask(__name__)

@app.route(‘/api/books’)

def get_books():

with open(‘data/books.json’) as f:

books = json.load(f)

return jsonify(books)

@app.route(‘/api/books/search’)

def search_books():

query = request.args.get(‘query’)

with open(‘data/books.json’) as f:

books = json.load(f)

if query:

filtered_books = [book for book in books if query.lower() in book[‘title’].lower()]

return jsonify(filtered_books)

else:

return jsonify(books)

if __name__ == ‘__main__’:

app.run()

This code sets up two Flask API endpoints: /api/books and /api/books/search. The first endpoint returns the entire dataset of books.

The second endpoint accepts a query parameter and returns a filtered dataset of books that match the query parameter in the book title. Step 2: Set up the front-end ReactJS application

Create a new ReactJS component called SearchBar and add the following code:

import React, { useState } from ‘react’;

function SearchBar({ onSearch }) {

const [query, setQuery] = useState(”);

const handleSubmit = e => {

e.preventDefault();

onSearch(query);

};

return (

setQuery(e.target.value)} />

);

}

export default SearchBar;

This code creates a new ReactJS component called SearchBar that accepts a callback function called onSearch.

The component renders an input field and a Submit button. When the user submits the form, the onSearch callback function is called with the current value of the input field.

Create a new ReactJS component called BookList and add the following code:

import React from ‘react’;

function BookList({ books }) {

return (

    {books.map(book =>

  • {book.title} by {book.author}
  • )}

);

}

export default BookList;

This code creates a new ReactJS component called BookList that accepts an array of books as a prop. The component renders an unordered list of books with the book title and author.

Create a new ReactJS component called SearchPage and add the following code:

import React, { useState, useEffect } from ‘react’;

import BookList from ‘./BookList’;

import SearchBar from ‘./SearchBar’;

function SearchPage() {

const [books, setBooks] = useState([]);

const [filteredBooks, setFilteredBooks] = useState([]);

useEffect(() => {

fetch(‘/api/books’)

.then(res => res.json())

.then(books => {

setBooks(books);

setFilteredBooks(books);

});

}, []);

const handleSearch = query => {

fetch(`/api/books/search?query=${query}`)

.then(res => res.json())

.then(books => setFilteredBooks(books));

};

return (

);

}

export default SearchPage;

This code creates a new ReactJS component called SearchPage that retrieves the entire dataset of books using the Fetch API. The retrieved data is stored in the state using the useState hook.

The component also passes a callback function to the SearchBar component that is called when the form is submitted. This callback function sends a request to the /api/books/search endpoint with the current value of the input field.

The retrieved data is then filtered and displayed on the page using the BookList component.

Understanding state changes within Components

In ReactJS, state is an object that holds data that can change over time and affects the rendering of the component. A component can change its state by calling the setState function.

When a component’s state changes, ReactJS will re-render the component and any child components that depend on the state. It is important to understand how state changes work in ReactJS, as they can have unintended consequences if not used correctly.

State changes should only be done using the setState function, as direct modification of the state object can cause unpredictable behavior. State changes should also be kept to a minimum, as they can be expensive operations.

Conclusion

ReactJS and Flask are two powerful technologies that can be used to create web applications. ReactJS provides a powerful front-end library for building complex user interfaces, while Flask provides a lightweight and flexible framework for building back-end logic.

When used together, these technologies can create dynamic and responsive web applications with ease. With the knowledge gained in this article, readers can start building their own web applications with ReactJS and Flask.

Gulp and Task Automation

Web development is a vital part of the digital age, and as the web evolves with various libraries, frameworks, and other technologies, so does web development. In the world of web development, task automation plays a vital role in ensuring that web development tasks can be completed quickly and efficiently.

Gulp is one such tool that can be used for task automation in web development. This article aims at helping readers understand how Gulp can be used to automate repetitive tasks in web development.

The role of Gulp as a task runner/build tool

At its core, Gulp is a task runner or build tool for web development. Gulp is used primarily for automating repetitive tasks in web development, such as minifying CSS and JavaScript files, concatenating files, and transforming file formats.

By using Gulp, developers can automate these tedious tasks, leaving more time for more involved development work.

Installing gulp and setting up the gulpfile

Before we can start using Gulp, we need to install it. The easiest way to install Gulp is by using Node Package Manager (NPM).

Once we have Node.js and NPM installed, we can use the following command to install Gulp globally:

npm install -g gulp-cli

Once Gulp is installed, we can set up the Gulpfile. The Gulpfile is where we define the tasks that we want to automate.

To create the Gulpfile, we need to create a new file in the root directory of our project called gulpfile.js. Once the file is created, we can start defining our tasks using the following syntax:

gulp.task(‘task-name’, function () {

// code to perform task

});

Using plugins like del, gulp-size, and reactify for task automation

One of the biggest benefits of Gulp is its flexibility.

There are numerous plugins available for Gulp that can help with specific tasks. Three useful plugins for task automation are del, gulp-size, and reactify.

The del plugin can be used to delete files or directories. This can be helpful in cleaning up build directories before running a new build.

The gulp-size plugin can be used to check the size of files, making it easier to optimize and compress files. The reactify plugin can be used to transform JSX files into JavaScript, making it easier to use React.

Transforming JSX files to JavaScript using gulp

Transforming JSX files to JavaScript is a common task in React development. To transform JSX files using Gulp, we can use the reactify plugin mentioned above.

We can create a new task in our Gulpfile that uses the reactify plugin like this:

gulp.task(‘jsx-to-js’, function () {

return gulp.src(‘./src/**/*.jsx’)

.pipe(reactify({ presets: [‘@babel/preset-react’]}))

.pipe(gulp.dest(‘./build’));

});

This task takes all of the JSX files in the src directory and transforms them into JavaScript files. The transformed files are then saved to the build directory.

Using gulp-watch to automatically re-run tasks

In web development, it can be time-consuming to manually run build tasks every time a file is changed. Gulp-watch is a helpful plugin for automatically re-running tasks when files are changed.

By using Gulp-watch, we can have our build process automated and continuously updated. To use Gulp-watch, we can create a new task in our Gulpfile that uses the gulp-watch plugin like this:

gulp.task(‘watch’, function () {

gulp.watch(‘./src/**/*.jsx’, [‘jsx-to-js’]);

});

This task watches all of the JSX files in the src directory.

Whenever one of these files is changed, the jsx-to-js task is automatically run.

Adding custom styles to the application

In web development, custom styles play a critical role in making your application visually appealing and user-friendly. CSS libraries such as Bootstrap and Materialize are often used to help with custom styling.

However, we may need to add custom styles that are not available in these libraries. To add custom styles to our application, we can create a new CSS file and include it in our HTML file using the link tag.

We can define all of the custom styles in this CSS file.

Additional resources and tutorials for learning React and Flask

React and Flask are both useful tools in web development. There are many resources and tutorials available for learning these tools.

Here are a few resources that may be helpful:

– React Official Documentation: https://reactjs.org/docs/getting-started.html

– Flask Official Documentation: https://flask.palletsprojects.com/en/2.1.x/

– Full-Stack Web Development with React and Flask (Udemy Course): https://www.udemy.com/course/full-stack-web-development-with-react-and-flask

– Flask Web Development with Python Tutorial Series (YouTube): https://www.youtube.com/watch?v=MwZwr5Tvyxo&list=PL-osiE80TeTs4UjLw5MM6OjgkjFeUxCYH

Conclusion

Gulp is a task runner/build tool that can be used for task automation in web development. By using Gulp, developers can automate repetitive and tedious tasks, leaving more time for more involved development work.

Del, gulp-size, and reactify are helpful plugins for task automation. Additionally, Gulp-watch is a useful plugin for automatically re-running tasks.

In web development, custom styles play an essential role in making an application visually appealing and user-friendly. Finally, many resources and tutorials are available to help learn React and Flask.

By mastering Gulp and using it in combination with these other technologies, developers can accelerate their web development workflows and create high-quality web applications. In conclusion, Gulp is an essential tool for web development that helps automate tedious and repetitive tasks, allowing developers to focus on more complex work.

Del, gulp-size, and reactify are some of the useful plugins available for task automation. Gulp-watch also provides automatic task running whenever changes are made to files.

Additionally, custom styles play a vital role in creating visually appealing and user-friendly web applications. Finally, there are various resources and tutorials available to learn React and Flask.

By incorporating Gulp and other technologies, web development can be more efficient and effective.

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