How to create and use a custom provider in Reactjs?

First, let’s understand what is a Provider.

The Provider is a special component provided by Redux, which makes the store available to all container components in the application without passing it around manually. You only need to use it once when you render the root component.

Here is how you can create and use a custom provider in React

Creating a Provider:

1. First, create a context, which will provide a way to pass data through the component tree without having to pass props down manually.

``` export const MyContext = React.createContext();
```

1. Then we create a Provider component:

``` export class MyProvider extends Component { state = { message: ‘Hello, World!’ };

render() { return ( {this.props.children} ); } } ```

Here, the Provider component receives a value prop to be passed to consuming components that are descendants of this Provider. One Provider can be connected to many consumers.

Using a Provider:

1. The Provider must wrap around the root component in your `ReactDOM.render()`. This ensures the data in the Provider is accessible throughout your app.

``` import { MyProvider } from ‘./MyProvider’;

ReactDOM.render( , document.getElementById(‘root’) ); ```

1. Finally, use the Context.Consumer in any child component to receive the relevant data.

``` import React from ‘react’; import { MyContext } from ‘../MyProvider’;

class MyClass extends React.Component { render() { {(context) => (

{context.state.message}

)} } } export default MyClass; ```

In this example, we import MyContext to get access to the `state` and correspondingly to it’s message property. `Context.Consumer` is a React component that subscribes to context changes. This allows you to subscribe to a context within a function component. It requires a function as a child; this function receives the current context value and returns a React node.

Please note that we may also utilize the `useContext` hooks as well for function components to become Consumers.

\`\`\`jsx import React, { useContext } from ‘react’; import { MyContext } from ‘../MyProvider’;

const MyFunctionComponent = () => { const context = useContext(MyContext); return (

{context.state.message}

); } export default MyFunctionComponent; \`\`\`

This way, the state will “flow down” the component hierarchy and any subscribing components will have access to it. It’s a great way to prevent “prop drilling” in your app, that is, passing props manually at every level. It also helps in managing global state in your application. Hope this helps!