Javascript - What is the best way to fetch data in react as chain where the second fetch depends on the data from the first fetch?

SkyLurk
October 13, 2023
206 views
1 vote
2 Answers

I am building a react app with a Firebase backend and I am stuck on fetching data in multiple steps where I use data from the first fetch as a parameter for data from the second fetch.

Below is my code:

  // GET DATA FROM FIRESTORE 
  const { getQrCode, getBranch } = DatabaseService();

This is how I fetch the first data. I have the ID in this case.

  // GET QR CODE 
  const fetchQRCode = async () => {
    const data = await getQrCode(id); //I have this ID
    setBranchQr(data);
  };

This is the second fetch that I need using the data from the first fetch:

  // GET BRANCH DATA
  const fetchBranchData = async () => {
    const data = await getBranch(branchQr.branchId); //I get this from the first fetch
    setBranchData(data);
    console.log(data)
  };

These are the useEffects:

   useEffect(() => {
    fetchQRCode();
    fetchBranchData();
    // eslint-disable-next-line react-hooks/exhaustive-deps
    }, []);
  useEffect(() => {}, [branchQr, branchData]);

Answers

Your approach seems to be problem-free. I usually use react-query to handle fetch requests because it simplifies the process and makes it straightforward. With react-query, there’s no need to manually use setState or other React hooks like useEffect. Additionally, there’s no need to set isLoading, and it offers a many tools to simplify the work.

I would recommend you to take a look at the Dependent Queries page of react-query at this link.

Here’s a simple example of using react-query from the official website:

// Get the user
const { data: user } = useQuery({
  queryKey: ['user', email],
  queryFn: getUserByEmail,
})

const userId = user?.id

// Then get the user's projects
const {
  status,
  fetchStatus,
  data: projects,
} = useQuery({
  queryKey: ['projects', userId],
  queryFn: getProjectsByUser,
  // The query will not execute until the userId exists
  enabled: !!userId,
})

Here is a step-by-step gruid:

Install Tanstack Queries using npm or yarn:

npm i @tanstack/react-query
yarn add @tanstack/react-query

Add it into your root js/ts react file like index.tsx or App.tsx:

import ReactDOM from "react-dom";
import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
import App from "src/App";

const queryClient = new QueryClient({});

ReactDOM.render(
  <QueryClientProvider client={queryClient}>
    <App />
  </QueryClientProvider>,
  document.getElementById("root")
);

In the component where you want the calls to be made, call the queries as follows:

import { useQuery } from "@tanstack/react-query";


// It's better to use a const for queryKey in order to export and use in future as follows.
export const REACT_QUERY_GET_QR_CODE_KEY = "GET_QR_CODE_KEY";
export const REACT_QUERY_GET_BRANCH_QUERY_KEY = "GET_BRANCH_QUERY_KEY";


const { data: nameThatMakesSenseToYou } = useQuery({
    queryFn: () =>  getQrCode(id),
    queryKey: [REACT_QUERY_GET_QR_CODE_KEY],
});

const branchId = nameThatMakesSenseToYou?.branchId;

const { status, data: branches } = useQuery({
  queryKey: [REACT_QUERY_GET_BRANCH_QUERY_KEY, branchId],
  queryFn: () => getBranch(branchId),
  enabled: !!branchId,
});

Just like said by Pooria, I would use Tanstack Queries

Install it using npm or yarn:

npm i @tanstack/react-query

Import it to your root JS file:

import { QueryClientProvider, QueryClient } from "@tanstack/react-query";

Create the client

  const queryClient = new QueryClient();

Wrap your root app

    <QueryClientProvider client={queryClient}>

    </QueryClientProvider>

Import your useQuery

import { useQuery } from "@tanstack/react-query";

Get the first set of data

      const { data: nameThatMakesSenseToYou } = useQuery({
    queryFn: () =>  getQrCode(id),
    queryKey: ["qrcode"],
  });

Create the branch ID from that first set of data

  const branchId = nameThatMakesSenseToYou.branchId;

Get the second set of data:

  const { status, data: branches } = useQuery({
    queryKey: ["branch", branchId],
    queryFn: () => getBranch(branchId),
    enabled: !!branchId,
  });

If you logged branches, you should see the data you are looking for.

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Javascript – What is the best way to fetch data in react as chain where the second fetch depends on the data from the first fetch?

Answers