README.md

Best Practices of React

Components

1. Small, focused components.
2. Use container components.

Small, focused components

What this means is that for instance you have a Button component.

You need to hide all the clumsy details inside that component, and having the component something like this:

<Button />  

Now, this component can be used anywhere inside the app without actually knowing what it does in the hindside. This is known as encapsulation.

We are encapsulating the logic totally inside that component.

  Previously, we tend to do something like this:

<Button className="btn"></Button>
<Button className="btn btn-primary"></Button>

className here is an implementation detail

Which specific class names my Button component uses. My uses of that component should not care about that.

The Button component should care about it, not us.

So, in React we do something like this:

<Button></Button>
<Button primary></Button>

We give button a property named primary, which will be used by the Button component.

Split containers and components

Splitting containers and components is a very good practice which will fetch you clean code. So let's go and see what does it mean in code.

Without splitting the container and component, our code-base looks like this:

class Sidebar extends React.Component {
	componentDidMount(){
		fetch('api.com/sidebar')
			.then(res => {
				this.setState({
					items: res.items
				})
			});
	
	}

	render(){

		return (
				<div className="sidebar">
					{
						this.state.items.map(item => (
							<div className="sidebar_item")>
							{item}
							</div>
						
						)
					}
				</div>
				
				);
	}
}

After splitting the container and components, this is something we get:

class SidebarContainer extends React.Component {
	componentDidMount(){
		fetch('api.com/sidebar')
			.then(res => {
				this.setState({
					items: res.items
				})
			});
	
	}

	render(){

		return (
				<Sidebar>
					{
						this.state.items.map(item => (
							<SidebarItem item={item} />	
						)
					}
				</Sidebar>
				
				);
	}
}

So, from the above illustration we can clearly see what the difference is all about:

In the second case (the cleaner one):

The container component is responsible for fetching the data and providing that data to its children (presentation components).

Whereas, the presentation components do the presentation work of displaying the data.

This paradigm makes our code cleaner to read and hence debugging will be much easier.

So the thing that you should always keep in mind is:

One component should be responsible for only one task unless an emergency knocks on the door.

Summarization of the second practice:

Containers: Care about How Things Work
Components: Care about How Things Look

What about Styling

CSS was designed in the age when web was made for scientific documents (in 1995). But now that scenario has completely changed. Now, the web doesn't consist only of text. So, the idea behind how to use styling must change and this is where the best practices of using styling have come up in component based systems.

Best Practices: Styling

1. Single-use classes
2. Components as a styling construct