Must have Custom hooks for NextJs

tigawanna

Dennis kinuthia

Posted on September 3, 2022

Must have Custom hooks for NextJs

useLocalStorage the custom hook

strapped this together to help save and retrieve the user-theme and token from the localstorage

was working on a react vite app and had to port it over to Next Js the ported next js app and i very quickly discovered that localStorage worked a little differently n Nextjs and i need it because that's where i was saving my personal access token and theme preferences which lead me down a rabbit hole which resulted in the following custom hook for that



import { useState,useEffect,useReducer } from 'react';
import { Viewer } from './../types/usertypes';

interface State{
token:string|null
theme:string|null
mainuser?:Viewer
error?:string
}


export const useLocalStorge=()=>{

const [loading, setLoading] = useState(true);
const [ state,dispatch] = useReducer(generalReducer,undefined);
useEffect(() => {
 const gen = window.localStorage.general; 
 if(gen){
  dispatch({ type: "INIT", payload: JSON.parse(gen) });
 }
 setLoading(false)
}, [])


useEffect(() => {
  const colorTheme = state?.theme === "dark" ? "light" : "dark";
  const root = window.document.documentElement;
    // console.log("colorTheme ==== ", colorTheme);
  root.classList.remove(colorTheme);
  // console.log("theme reset to ==== ",state?.theme)
  if(state?.theme){
    root.classList.add(state?.theme);
  }

}, [state?.theme]);



useEffect(() => {
if(state)
window.localStorage.setItem("general",JSON.stringify(state))
}, [state])

return {loading ,state ,dispatch}
}






function generalReducer(state:State, action:any) {
switch (action.type) {

  case "INIT":
    return action.payload;
  case "THEME":
    return {...state,theme:action.payload}
  case "TOKEN":
    return {...state,token:action.payload}  
  case "ERROR":
    return {...state,error:action.payload} 

  default:
    return state;
}
}


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and you consume it like

import "../styles/globals.css";
import type { AppProps } from "next/app";
import { ReactQueryDevtools } from "react-query/devtools";
import { QueryClient, QueryClientProvider } from "react-query";
import { Layout } from "../components/Layout";
import { useLocalStorge } from "./../utils/hooks/useLocalStorge";
import GlobalContext from "../utils/context/GlobalsContext";

const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      refetchOnWindowFocus: false,
      refetchOnMount: false,
      refetchOnReconnect: false,
      retry: false,
      staleTime: 5 * 60 * 1000,
    },
  },
});

function MyApp({ Component, pageProps }: AppProps) {
  const local = useLocalStorge();
  // console.log("local state ==== ",local?.state)

  // console.log("initial value in local storage ==== ", value);

  return (
    <QueryClientProvider client={queryClient}>
      <GlobalContext.Provider
        value={{ value: local?.state, updateValue: local?.dispatch }}
      >
        <Layout local={local}>
          <Component {...pageProps} />
          <ReactQueryDevtools />
        </Layout>
      </GlobalContext.Provider>
    </QueryClientProvider>
  );
}

export default MyApp;


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the cotext is optonnal but it looks like this

import React, { Dispatch } from "react";
import { Viewer } from './../types/usertypes';

export interface Value {
  token: string | null;
  theme:string
  error?: string;
  mainuser?:Viewer
}
interface Type {
  value: Value;
  updateValue:Dispatch<any>
}

const init_data: Type = {
  value:{token:null,theme:"light"},
  updateValue: (any) => {},
};

const GlobalContext = React.createContext(init_data);
export default GlobalContext;

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final project looks like

💖 💪 🙅 🚩
tigawanna
Dennis kinuthia

Posted on September 3, 2022

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