How To Conditionally Add Attributes To React Components?

In React, it's common to render components based on certain conditions dynamically. Often, you may need to add or remove attributes to a React component based on the application's state, the props passed down, or other factors. Handling these dynamic conditions effectively is key to building flexible and dynamic user interfaces.

In this article, we will explore some methods for conditionally adding attributes to React components.

Approach 1: Implicit Omission of False Values

React is intelligent enough to omit certain attributes when they are given a false value. This is particularly useful for inherently boolean attributes, like disabled, required, checked, etc. If the value of these attributes is false, React will not render the attribute at all, which is convenient for conditionally controlling their presence.

Syntax:

state= {
    disabled: false,
    required: true
}

return (
    <input type="text" disabled={disabled} required={required}  />
);

The above Syntax will result in the following output:

<input type="text" required>

Steps To Conditionally Add Attributes To React

Step 1: Create a React application using the following command:

npx create-react-app foldername
cd foldername

Project Structure

Example:

import React, { Component } from "react";
class App extends Component {

    state = {
        disabled: true,
        text: "Make it Unable"
    }

    updateState = () => {
        let text = !this.state.disabled ? "Make it Unable" : "Make it Disable";
        this.setState({ disabled: !this.state.disabled, text: text })
    }

    render() {
        return (
            <div>
                <input type="text" disabled={this.state.disabled} />
                <button
                    onClick={this.updateState}>
                    {this.state.text}
                </button>
            </div>
        );
    }
}

export default App;

Output:

Approach 2: Conditional Attribute Spread with the Spread Operator

Another method to conditionally add attributes in React is by using the spread operator (...) with an inline conditional expression. This approach is particularly useful when dealing with more complex attributes like className, style, or custom props, where you want to dynamically add them only when a certain condition is met.

state {
    condition: true
}

return (
    <Button {...(condition ? {className: 'btn btn-primary'} : {})} />
);

Depending on the value of condition either the {className: 'btn btn-primary'} or {} will be returned. The Spread Operator will then spread the returned object properties to the Button component. In the falsy case, because the returned object has no properties, nothing will be passed to the component.

Example:

import React, { Component } from "react";
class App extends Component {

    state = {
        condition: true

    }

    updateState = () => {
        this.setState({ condition: !this.state.condition })
    }
    render() {
        return (
            <div>
                <button
                    {...(this.state.condition ? { className: 'btn btn-primary' } : {})}
                    onClick={this.updateState}>
                    click
                </button>
            </div>
        );
    }
}

export default App;

Output: