Using React Context for State Management

In this lesson, we'll learn about React Context, a built-in feature that allows us to manage global state in a React application without prop drilling.

Understanding Global State

• Explain the concept of global state and why it's essential for certain data that needs to be accessible across multiple components.

Create a Context

• In your project, create a new file called AppContext.js.
• Import React and create a new context using React.createContext().

  import React from 'react';
  const AppContext = React.createContext();

Wrap the App with Context Provider

• In your main application file (e.g., App.js), wrap the entire application with the AppContext.Provider.
• Provide an initial value for the context (this can be an object or a state variable).

Accessing Global State

• In any component that needs access to the global state, import the AppContext and use the useContext hook to access the data.

  import React, { useContext } from 'react';
  import AppContext from './AppContext';
  
  function MyComponent() {
    const appState = useContext(AppContext);
    // Use appState data as needed
  }

Updating Global State

• To update the global state, create functions in the AppContext file that modify the state. You can pass these functions down through the context to be used in child components.

  const AppContext = React.createContext();
  
  function AppContextProvider({ children }) {
    const [globalState, setGlobalState] = React.useState(initialState);
  
    const updateGlobalState = (newValue) => {
      setGlobalState(newValue);
    };
  
    return (
      <AppContext.Provider value={{ state: globalState, updateState: updateGlobalState }}>
        {children}
      </AppContext.Provider>
    );
  }

Testing the Context Provider

• Test the global state by updating it in one component and verifying that the changes are reflected in other components that access the context.

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By the end of this lesson, you'll have a basic understanding of how to use React Context to manage global state in your application.