CODEWITHSUNDEEP
javascriptreactjsreact-hooksreact-contextuse-context
Jagarkin
Jagarkin

Reputation: 620

state do not change with useContext

hello

I am trying to make a menu toggle, where I have a variable with false as initial value, using react createContext and useContext hook, I set the initial state as true

// useMenu Context
import React, { useContext, useState } from 'react'

export const useToggle = (initialState) => {
  const [isToggled, setToggle] = useState(initialState)
  const toggle = () => setToggle((prevState) => !prevState)
  // return [isToggled, toggle];
  return { isToggled, setToggle, toggle }
}

const initialState = {
  isMenuOpen: true,
  toggle: () => {},
}

export const MenuContext = React.createContext(initialState)

const MenuProvider = ({ children }) => {
  const { isToggled, setToggle, toggle } = useToggle(false)
  const closeMenu = () => setToggle(false)
  return (
    <MenuContext.Provider
      value={{
        isMenuOpen: isToggled,
        toggleMenu: toggle,
        closeMenu,
      }}>
      {children}
    </MenuContext.Provider>
  )
}
export default MenuProvider

export const useMenu = () => {
  return useContext(MenuContext)
}

so If true it will show the Menu if false it will show the Div where there a div

App.js

const { isMenuOpen } = useMenu()

//the providder
<MenuProvider>
  <Header mode={theme} modeFunc={toggleTheme}/>
      {isMenuOpen ? (
         <Menu />
      ) : (
      <Switch>
        <Route path='/writing' component={Writings} />
        <Route path='/meta' component={Meta} />
        <Route path='/contact' component={Contact} />
        <Route path='/project' component={Project} />
        <Route exact path='/' component={Home} />
        <Route path='*' component={NotFound} />
      </Switch>
    )}
  <Footer />{' '}
</MenuProvider>

and when I add an onclick event the NavLink button of the menu to close it it does not work

Menu


const { closeMenu } = useMenu()
// return statement
{paths.map((item, i) => {
  return (
    <MenuItem
      key={i}
      link={item.location}
      svg={item.icon}
      path={item.name}
      command={item.command}
      onClick={closeMenu}
     />
  )
})}

where did I go wrong

Upvotes: 2

Views: 994

Answers (1)

Drew Reese
Drew Reese

Reputation: 202605

Issue

I suspect the issue is in App where you've a useMenu hook outside the MenuProvider used in App. This useMenu hook is using a MenuContext context but in the absence of a provider it instead uses the default initial context value.

const initialState = {
  isMenuOpen: true,
  toggle: () => {},
};

export const MenuContext = React.createContext(initialState);

export const useMenu = () => {
  return useContext(MenuContext)
};

React.createContext

const MyContext = React.createContext(defaultValue);

Creates a Context object. When React renders a component that subscribes to this Context object it will read the current context value from the closest matching Provider above it in the tree.

The defaultValue argument is only used when a component does not have a matching Provider above it in the tree. This default value can be helpful for testing components in isolation without wrapping them.

Solution

Since I doubt you want to run/provide more than one menu provider I believe the solution is to move MenuProvider out of and wrap App to provide the context you are updating by nested components.

App.jsx

const { isMenuOpen } = useMenu();

...

<>
  <Header mode={theme} modeFunc={toggleTheme}/>
  {isMenuOpen ? (
    <Menu />
  ) : (
    <Switch>
      <Route path='/writing' component={Writings} />
      <Route path='/meta' component={Meta} />
      <Route path='/contact' component={Contact} />
      <Route path='/project' component={Project} />
      <Route exact path='/' component={Home} />
      <Route path='*' component={NotFound} />
    </Switch>
  )}
  <Footer />
</>

index.jsx (?)

import App from './App.jsx';

...

//the provider
<MenuProvider>
  <App />
</MenuProvider>

Upvotes: 2

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