One-way data flow in ReactJS in 5 easy steps

One-way data flow in React also known as Unidirectional data flow, is a concept in React that refers to the direction in which data flows in a React application.

1. What is One-way or Unidirectional data flow

In the one-way data flow, data flow in a single direction, from the parent component to the child component. One-way data flow is a key aspect of React and helps to make React applications scalable, maintainable, and easy to develop.

2. How one-way data flows in React Application

When a parent component updates its state, it passes the updated state down to the child components.
The child components can use the props to render themselves.
The parent can change the state of the child component through props but a child cannot modify the props or change the state of a parent component.

3. Advantages of One-way data flow

It has a lot of benefits mentioned below:

It helps to make data flow predictable and easier to understand and debug.
It also helps to enforce the separation of concerns.
It improves the modularity of components.
Each component only needs to worry about its own state and props, rather than try to manage the state of the entire app.

4. Code Example

Create a React project, in case you want to check out how to create React project then check out “Create ReactJS project from scratch“.
Once the project is created, write the code given below.

ParentComponent.js

import React from "react";

class ParentComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      text: "Hello, world!",
    };
  }

  render() {
    return (
      <div>
        <ChildComponent text={this.state.text} />
      </div>
    );
  }
}

class ChildComponent extends React.Component {
  render() {
    return (
      <div>
        {this.props.text}
      </div>
    );
  }
}

export default ParentComponent;

App.js

import React from "react";
import ParentComponent from "./ParentComponent";

function App() {
  return (
    <div>
      <ParentComponent />
    </div>
  );
}

export default App

And run the program by opening a terminal and running the command

npm start

Once it runs, you will see a page in your browser with “Hello, world!”.

In this example, the ParentComponent maintains the state variable text and passes it down to the ChildComponent as a prop. The ChildComponent receives the text prop and display it inside a div.
In the App.js file, the ParentComponent is imported and rendered.
This demonstrates one-way data flow since the text data flows in a single direction from the parent component to the child component and cannot be modified by the child component.

5. Summary

One-way data flow in React can be thought of as a pipeline that carries data from a parent component to its child components. The data flow in one direction only, from the parent to the child components to modify or change the data. This helps to keep the data and the components organized and separate, making the app easier to understand and debug.

I hope this content will be enough to understand what is a one-way data flow and how it works. If your want to learn more about ReactJS, you can follow all the ReactJS tutorials starting from “Introduction to React” on devcribe.com. Happy Coding!