Introduction
Welcome to React universe, if you’re still new to this javascript library then you might have come across a term called “props”. Props is a way to pass data from one component to another.
Understanding how to use props effectively is a crucial part of building React applications, and it can take a bit of time to get the hang of it but don't worry, with a little bit of practice and some helpful tips, you will be a props pro in no time so let’s get started!
What are props in React?
Properties are referred to as "Props" in React. They are an important part of react components, which enable the transfer of data across components. They support the development of dynamic, reusable components.
Passing props within components
Props usually are passed in a downward flow in react application from top to bottom. It gets trickier when it’s passed upwards but it’s possible with the use of Redux and third-party libraries e.g react-broadcast.
Some of the basic uses of props are ;
Passing data to child components: this is the most common way for props to pass data to the child component this lets you create reusable components. For example, you might pass a "title" prop to a "Header" component to display a custom title for each page in your application.
Conditional rendering: props can be used to conditionally render components or elements. By passing a boolean prop, for example, you can control whether a component is displayed or hidden based on some condition in your application. For example, you can control whether a component is displayed or hidden based on some condition in your application.
Using callbacks to pass data: You can also use callbacks to pass data between components. It involves passing a callback function as a prop from a parent component to a child component, which the child component can then call with data as an argument. For example, you might pass a "selectOption" callback prop to a "Dropdown" component, which the component can then call with the selected option as an argument.
Event handling: In addition to passing data, props can also be used to pass event handlers from a parent component to a child component. This allows the child component to trigger a function in the parent component in response to user interactions. For example, you might pass an "onClicked" prop to a "Button" component, which the component can then use to trigger a function when the button is clicked.
Accessing props within class-based components
A class-based component is a way of defining a component in React using a JavaScript class, using the "this.props” object, a class-based React component may access props handed down from a parent component. If you are not familiar with "this" I advise reading this article. The "render" function of the class returns the user interface that the component will show.
In this example, we've created a class-based component called “Client”. The component takes in a prop called “name”, which it displays inside a P tag. So for this component to work we have to create an instance and pass in the “name” prop as seen in fig 3.
Class-based components were the primary way of defining components in React before the introduction of functional components with hooks.
Accessing props within function-based components
Personally, I prefer using this method compared to the class-based components, it’s much easier to understand. In a function-based component, you can access props by passing them as an argument to the function.
In this example, we've defined a function-based component called “Client”. It takes in a prop called “name”, which it displays inside a P tag using curly braces to access the value of the “name” prop.
The Client.js (child component), is receiving the data from App.js (parent component) through props.
To use this component, you would create an instance of it and pass in the “name” prop like this:
This would create a “Client” component that displays the text "John Puller" inside a p tag.
Here’s the CSS style:
How the output will look like:
Best Practices for Using Props in React
Keep props simple: Try to keep the number of props passed to a component to a minimum. If a component needs many props, consider splitting it into smaller, simpler components that can be composed together.
Give your props meaningful names: Use names that are clear and descriptive and represent their intended usage. While reading a component's code or documentation, makes it simpler to comprehend the function of the component.
Don't mutate props: Props should be treated as read-only, immutable values. Avoid modifying props directly within a component, as this can lead to hard-to-find bugs and unexpected behaviour.
Keep prop types consistent: Use consistent prop types throughout your codebase, and avoid mixing different types for the same prop. This makes it easier to understand how props are used and what their expected values are.
Use Prop drilling carefully: Prop drilling can help deliver data down to deeply nested components, but it can also become complex and difficult to manage. If prop drilling becomes too complicated, consider using React context or other state management options.
Use default props: Use default props to set default values for props that aren't required, but may be useful in certain situations. This makes it easier to use the component in different contexts, without needing to pass in every possible prop value.
Conclusion
In conclusion, understanding props is a fundamental concept in React development. You can create more reliable and maintainable apps with reusable components by adhering to best practices and learning more about how props function in React.