Kevin Powell - Community•10mo ago

[React/NextJS] Any React Devs that can help figure out where we've gone short with this Cart?

https://github.com/callum-laing/shopping-site/tree/main We're using localStorage and useEffect.. I think we're close, but we can't quite figure out the final hurdle to get over the finish line... We're working in app/cart/page.jsx and app/shop/page.jsx.

78 Replies

CDLOP•10mo ago

pushes this to the top

b1mind•10mo ago

const Cart = () => {
  const searchParams = useSearchParams();
  const id = searchParams.id;
const storedItems = JSON.parse(localStorage.getItem("items"));

  const [items, setItems] = useState(storedItems);

  useEffect(() => {
    if (id) {
    const newItem = posts.filter((item) => item.id === id);
    items.push(newItem)
    setItems(items);
    }
localStorage.setItem("items", JSON.stringify(items));
  }, [items]);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      <p>
        {items.map((item) => (
          <div key={item.id}>
            {item.id}
            {item.name}
            {item.price}
            {item.image}
          </div>
        ))}
      </p>
    </div>
  );
};

export default Cart;

const Cart = () => {
  const searchParams = useSearchParams();
  const id = searchParams.id;
const storedItems = JSON.parse(localStorage.getItem("items"));

  const [items, setItems] = useState(storedItems);

  useEffect(() => {
    if (id) {
    const newItem = posts.filter((item) => item.id === id);
    items.push(newItem)
    setItems(items);
    }
localStorage.setItem("items", JSON.stringify(items));
  }, [items]);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      <p>
        {items.map((item) => (
          <div key={item.id}>
            {item.id}
            {item.name}
            {item.price}
            {item.image}
          </div>
        ))}
      </p>
    </div>
  );
};

export default Cart;

Something like this 🤔 In my mind this works 😂 I should find a playground to just put your code in mmm yea idk all sorts of issues when I try it in stack blitz use client seems like bs 🤣 casue I had to check to see if window exists to use localStorage which is fine but I thought that is what the whole use client string was for. cause its trying to run ont he server first. https://stackblitz.com/edit/stackblitz-starters-rtgg9j?description=The%20React%20framework%20for%20production&file=app%2Fcart%2Fpage.jsx,app%2Fshop%2Fpage.jsx&title=Next.js%20Starter idk if that works cause I didn't save it but yea... what a mess. Really don't get whats so hard about this... fukin React/NextJS

CDLOP•10mo ago

you're not gonna give up are ya

b1mind•10mo ago

export default function Cart() {
  const searchParams = useSearchParams();
  const id = searchParams.id;

  const store = localStorage.getItem('items');
  const storedItems = JSON.parse(store);
  const [items, setItems] = useState(storedItems);

  useEffect(() => {
    const newItem = posts.filter((item) => item.id === id);
    if (newItem) {
      setItems(newItem);
    }
    localStorage.setItem('items', JSON.stringify(items));
  }, []);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      <p>
        {/* {items.map((item) => (
          <div key={item.id}>
            {item.id}
            {item.name}
            {item.price}
            {item.image}
          </div>
        ))} */}
      </p>
    </div>
  );
}

export default function Cart() {
  const searchParams = useSearchParams();
  const id = searchParams.id;

  const store = localStorage.getItem('items');
  const storedItems = JSON.parse(store);
  const [items, setItems] = useState(storedItems);

  useEffect(() => {
    const newItem = posts.filter((item) => item.id === id);
    if (newItem) {
      setItems(newItem);
    }
    localStorage.setItem('items', JSON.stringify(items));
  }, []);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      <p>
        {/* {items.map((item) => (
          <div key={item.id}>
            {item.id}
            {item.name}
            {item.price}
            {item.image}
          </div>
        ))} */}
      </p>
    </div>
  );
}

I mean I'm close 🤣 if it would just read the localStorage >.>;;

b1mind•10mo ago

b1mind•10mo ago

cause it thinks its on the server and window object ofc does not exists

CDLOP•10mo ago

should I build this in vite to use context api to finish it, then leave our attempt how it is until we find a fix? lol

b1mind•10mo ago

I mean you do you xD lol At this point I'm just back to remembering why I think its al lshit SvelteKit ftw

CDLOP•10mo ago

hahaha yea, dont tempt me

b1mind•10mo ago

😂

CDLOP•10mo ago

IF I enjoy BE, you know i'm jumping back on svelte quicker than you can say boo lol

b1mind•10mo ago

mmm I do see errors in my code but nothing helps if I can't get localStorage read... whats f'd too is I had it kinda working 😂

CDLOP•10mo ago

so localstorage is the issue huh. best we get rid of it 😄 what about uhh... context? 🤣

b1mind•10mo ago

not going to solve your issues here its not localStorage persay its where the code runs as I just said. You would still want to use localStorage with Context API if you wanted a persitant store. So unless you were doing a SPA wouldn't matter here

CDLOP•10mo ago

yea I was joking

b1mind•10mo ago

oh right just use a wrapper cause its boilplatey af xD

b1mind•10mo ago

https://medium.com/@lean1190/uselocalstorage-hook-for-next-js-typed-and-ssr-friendly-4ddd178676df

Medium

useLocalStorage hook for Next.Js, typed, and SSR friendly

I am learning React and Next.js, and I needed a way to access the localStorage without running into problems with SSR. Hooks to the rescue.

CDLOP•10mo ago

tryna wrap my head around context with their wordy wordyness in this course, quite the brain frazzler, but I get the jist of it.

b1mind•10mo ago

https://usehooks-ts.com/react-hook/use-local-storage

useLocalStorage

Custom hook that uses local storage to persist state across page reloads.

b1mind•10mo ago

cause in React you can't just do things without importing a wrapper fml 🤦‍♂️ I mean I have to check for browser in my Svelte Store too but >.>;;

import { writable } from 'svelte/store'
import { browser } from '$app/environment'

export const persistStore = function (key, initial) {
    // if (browser && !document.hasStorageAccess()) document.requestStorageAccess()

    const persist = browser ? localStorage.getItem(key) : false
    const data = persist ? JSON.parse(persist) : initial

    const store = writable(data, () => {
        const unsubscribe = store.subscribe((value) => {
            browser ? localStorage.setItem(key, JSON.stringify(value)) : false
        })
        return unsubscribe
    })
    return store
}

import { writable } from 'svelte/store'
import { browser } from '$app/environment'

export const persistStore = function (key, initial) {
    // if (browser && !document.hasStorageAccess()) document.requestStorageAccess()

    const persist = browser ? localStorage.getItem(key) : false
    const data = persist ? JSON.parse(persist) : initial

    const store = writable(data, () => {
        const unsubscribe = store.subscribe((value) => {
            browser ? localStorage.setItem(key, JSON.stringify(value)) : false
        })
        return unsubscribe
    })
    return store
}

This is what you would do with ContextAPI too probabaly 10x more code though 🤣

CDLOP•10mo ago

just a bunch of words to me

b1mind•10mo ago

Yea I'm done I'll let someone who actually enjoys NextJS to help you I tried xD

CDLOP•10mo ago

you gave it your best shot

b1mind•10mo ago

meh I gave it my best "I hate this" shot 🤣 the answers are there for ya just gotta implement it with the hook wrapper or making your own. almost be easier to just setup sqlite and use the RSC 😂

CDLOP•10mo ago

I began doing it in vite just to see how it works wit hcontext etc to have a finished product until we can get someone to help, and I already regret starting lmao well that was the plan wasn't it, lol learn some backend, come back, jazz it up

b1mind•10mo ago

yea do that

CDLOP•10mo ago

ill get rid of this vite project, we'll come back to this later if no-one helps in the mean time

CDLOP•10mo ago

Hah.

b1mind•10mo ago

😉 I use it all ALL THE THINGS Localstorage is great for local info

WhoSalty•10mo ago

"use client";
import posts from "../data";
import { useSearchParams } from "next/navigation";
import React, { useState, useEffect } from "react";

const Cart = () => {
  const searchParams = useSearchParams();
  const id = searchParams.get("id");

  const [items, setItems] = useState(() => JSON.parse(localStorage.getItem("items") || "[]"));

  useEffect(() => {
    const newItem = posts.find((item) => item.id === parseInt(id));

    if (newItem) {
      return () => {
        setItems((prevItems) => [...prevItems, newItem]);
        localStorage.setItem("items", JSON.stringify([...items, newItem]));
      }
    }
  }, []);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      {items.map((item, index) => (
        <div key={index}>
          {item.id}
          {item.name}
          {item.price}
          {item.image}
        </div>
      ))}
    </div>
  );
};

export default Cart;

"use client";
import posts from "../data";
import { useSearchParams } from "next/navigation";
import React, { useState, useEffect } from "react";

const Cart = () => {
  const searchParams = useSearchParams();
  const id = searchParams.get("id");

  const [items, setItems] = useState(() => JSON.parse(localStorage.getItem("items") || "[]"));

  useEffect(() => {
    const newItem = posts.find((item) => item.id === parseInt(id));

    if (newItem) {
      return () => {
        setItems((prevItems) => [...prevItems, newItem]);
        localStorage.setItem("items", JSON.stringify([...items, newItem]));
      }
    }
  }, []);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      {items.map((item, index) => (
        <div key={index}>
          {item.id}
          {item.name}
          {item.price}
          {item.image}
        </div>
      ))}
    </div>
  );
};

export default Cart;

try this

CDLOP•10mo ago

I’ll try this when I’m home in a few hours, thanks for the attempt! 🤞 Alright I tried it, but it didn't fix the problem... nice effort though 😅

b1mind•10mo ago

what does it get hung on? I wasn't aware you could do anons like that in the useEffect/state hooks it looked like a interesting solution

CDLOP•10mo ago

this appeared in the terminal, but in dev tools there's no error

CDLOP•10mo ago

but I get this

b1mind•10mo ago

ah same issue

CDLOP•10mo ago

aye

b1mind•10mo ago

ya its trying to use localStorage on the server which is like window what? use client is a lie? lol

glutonium•10mo ago

items.push() this feels illegal 😂

b1mind•10mo ago

I mean lol

glutonium•10mo ago

can't we do

setItem(preItem => preItem.push())

setItem(preItem => preItem.push())

b1mind•10mo ago

its faster than [newItem, ...items] but I don't konw how that works with React and rerendering if it ignores it.

glutonium•10mo ago

hmm fair i mean since u r not allowed to directly change state it just feels so wrong to do 😂

b1mind•10mo ago

the issue is getting localStorage read to not wig out thinking its serverside xD

glutonium•10mo ago

hmm i see damn i need to get good with react ;-;

b1mind•10mo ago

I think its horrid, but I don't have to use it lol

glutonium•10mo ago

i learnt about useState and useEffect and just ran away with my life

WhoSalty•10mo ago

Oh, it works in dev mode lol, got to do some extra things to make it run in production due to window and local storage

CDLOP•10mo ago

yeah we figured that, nice attempt though! I think ill probably come back to it once ive learned soem backend and throw that in there instead haha

WhoSalty•10mo ago

ill give it another crack in a few, it was a fun challenge, anything to get me off css lol

"use client";
import posts from "../data";
import { useSearchParams } from "next/navigation";
import React, { useState, useEffect } from "react";
import { Suspense } from "react";

const CartComponent = () => {
  const searchParams = useSearchParams();
  const id = searchParams.get("id");

  const [items, setItems] = useState(() => {
    if (typeof window !== "undefined") {
      return JSON.parse(localStorage.getItem("items") || "[]");
    } else {
      return [];
    }
  });

  useEffect(() => {
    const newItem = posts.find((item) => item.id === parseInt(id));

    if (newItem) {
        setItems((prevItems) => [...prevItems, newItem]);
        localStorage.setItem("items", JSON.stringify([...items, newItem]));
    }
  }, []);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      {items.map((item, index) => (
        <div key={index}>
          {item.id}
          {item.name}
          {item.price}
          {item.image}
        </div>
      ))}
    </div>
  );
};


export default function Cart() {
  return (
    <Suspense>
      <CartComponent />
    </Suspense>
  )
}

"use client";
import posts from "../data";
import { useSearchParams } from "next/navigation";
import React, { useState, useEffect } from "react";
import { Suspense } from "react";

const CartComponent = () => {
  const searchParams = useSearchParams();
  const id = searchParams.get("id");

  const [items, setItems] = useState(() => {
    if (typeof window !== "undefined") {
      return JSON.parse(localStorage.getItem("items") || "[]");
    } else {
      return [];
    }
  });

  useEffect(() => {
    const newItem = posts.find((item) => item.id === parseInt(id));

    if (newItem) {
        setItems((prevItems) => [...prevItems, newItem]);
        localStorage.setItem("items", JSON.stringify([...items, newItem]));
    }
  }, []);

  return (
    <div>
      <h2>Please proceed to give me your card details!</h2>
      {items.map((item, index) => (
        <div key={index}>
          {item.id}
          {item.name}
          {item.price}
          {item.image}
        </div>
      ))}
    </div>
  );
};


export default function Cart() {
  return (
    <Suspense>
      <CartComponent />
    </Suspense>
  )
}

Tenkes•10mo ago

So the way Next works is it renders components on server and sends rendered HTML to the client. However sometimes we need to use client-side stuff in our components such as localStorage, React hooks etc. In that case we mark component as client component with "use client" at the top of the file so Next knows it should be rendered on the client . However client components are initially rendered on server, and then on client. I'm not sure exactly how and why that works but that's why sometimes we need to first make sure we're on client-side using if (typeof window !== 'undefined') {/* ... */} before doing some client side stuff. We don't need it for hooks though, I guess they have client-side check inside of them or something lol. @b1mind hope this clears some things out 😂

b1mind•10mo ago

I already understood this I'm triggered by how stupid it is to have use-client and still have to check for window But I get it cause if it can it will render it out ssr first then client SvelteKit is very much the same way and* you do have to check if browser there too. >.>;;

We don't need it for hooks though, I guess they have client-side check inside of them or something lol.

can you give an example of this cause yea that is what I thought if it was inside a effect/state hook you didn't need to check window object. This seems to work 🤘 well kinda... seems to keep the last added in the array so you get two of it till you come back 🤔

WhoSalty•10mo ago

have you cleared localstorage

b1mind•10mo ago

yea mate

b1mind•10mo ago

WhoSalty•10mo ago

i didn’t seem to get that 🤔 but code is code

b1mind•10mo ago

facts xD lol

WhoSalty•10mo ago

im unhappy with it anyway due to the exhaustive deps warning 😢

b1mind•10mo ago

useEffect(() => {
    const newItem = posts.find((item) => item.id === parseInt(id));

    if (newItem) {
      setItems([...items, newItem]);
      localStorage.setItem('items', JSON.stringify([...items, newItem]));
    }
  }, []);

useEffect(() => {
    const newItem = posts.find((item) => item.id === parseInt(id));

    if (newItem) {
      setItems([...items, newItem]);
      localStorage.setItem('items', JSON.stringify([...items, newItem]));
    }
  }, []);

seems to do it

WhoSalty•10mo ago

im going to try and move the deps into the useeffect but when i try i get loops lol and still end up needing searchParams

b1mind•10mo ago

you could use a dynamic route too as I was telling CDL

WhoSalty•10mo ago

i’m honestly not familiar with nextjs new apps route thing, still doing it the old way

b1mind•10mo ago

old way the clientside only way? or pre folder routing you mean?

WhoSalty•10mo ago

uhm, just the structure, src/api, src/pages etc the latter i suppose

b1mind•10mo ago

gotcha yea it is teh way I don't do React though so I don't have a leg in the race 🤣 if I did I'd probably pick Remix though

WhoSalty•10mo ago

i think i ran into problems utilizing Prisma Orm with the new way ran back to what i knew anyways, i relearned a lot about useEffect trying to fix this, 🫡

b1mind•10mo ago

Yea I gotta learn a little bit too, and how much I'd rather still use SvelteKit 🤣

CDLOP•10mo ago

glad you did useEffect, I hate it. Hah I get the item being added twice with your latest attempt, update: it seems to work

b1mind•10mo ago

if you use the edited bit I did you wont this bit

WhoSalty•10mo ago

I am still thinking about if the localstorage set should be done on unmount or not 🤔

b1mind•10mo ago

I mean it should be a persistent store but this works for now 😄

WhoSalty•10mo ago

yeah if it works :thumbup:

b1mind•10mo ago

this is what I'd probably use, or make my own.

CDLOP•10mo ago

yeah don't need to go wild on it haha, I really appreciate the efforts!

WhoSalty•10mo ago

how do we make it work without exhaustive deps warning 😩 you would think an empty dep array is a react feature so that we can explicitly state we want this effect to run once

CDLOP•10mo ago

sorry what deps warning? I seem to get this

CDLOP•10mo ago

though weirdly, now whwnever i refresh it adds an item to the cart

WhoSalty•10mo ago

i get an exhaustive deps lint warning when building no me gusta eso amigo 👴🏼

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