如何获取数据并存储在 React Context API 中？

Question

第一次使用上下文API所以请多多包涵

我有一个本地 JSON 文件，我试图从中获取并将响应放在上下文中 API，这样我就可以在应用程序周围全局使用。

在本地运行应用程序时，出现空白屏幕并且页面似乎无法加载。该页面处于无限循环中，所以我看不到它是否正在加载。

Codesandbox here.

知道我可以更改什么以成功将数据响应引入上下文 API 吗？

apiContext.js:

import React, { useContext, useState, useEffect, createContext } from "react";
import axios from "axios";

const APIContext = createContext();

function APIContextProvider({ children }) {
  // Initialize state
  const [data, setData] = useState([]);
  const [isLoading, setIsLoading] = useState(true);

  // Fetch data
  useEffect(() => {
    let url = "../db.json";
    axios
      .get(url)
      .then(function (response) {
        setData(response.data.machines);
        setIsLoading(false);
        console.log(response.data.machines);
      })
      .catch((error) => console.log(error));
  }, []);

  return (
    <APIContextProvider value={{ data }} loading={isLoading}>
      {children}
    </APIContextProvider>
  );
}

export default APIContextProvider;

// Create a hook to use the APIContext, this is a Kent C. Dodds pattern
export function useAPI() {
  const context = useContext(APIContext);
  if (context === undefined) {
    throw new Error("Context must be used within a Provider");
  }
  return context;
}

App.js:

import "./App.css";
import List from "./List";
import APIContextProvider from "./context/apiContext";

function App() {
  return (
    <APIContextProvider>
      <div className="App">
        <List />
      </div>
    </APIContextProvider>
  );
}

export default App;

List.js:

import React from "react";
import { useAPI } from "./context/apiContext";

const FetchData = ({ isLoading }) => {
  // Grab data from useAPI in global context
  const { data } = useAPI();

  return (
    <div>{!isLoading ? <p>{data[0].category}</p> : <p>Loading...</p>}</div>
  );
};

export default FetchData;

Answer 1

试试这个。

// apiContext.js
  return (
    <APIContext.Provider value={{ data, isLoading }}>
      {children}
    </APIContext.Provider>
  );

// List.js
const FetchData = () => {
  // Grab data from useAPI in global context
  const { data, isLoading } = useAPI();

  return (
    <div>{!isLoading ? <p>{data[0].category}</p> : <p>Loading...</p>}</div>
  );
};

如何获取数据并存储在 React Context API 中？

How to fetch data and store in React Context API?

javascript

reactjs

axios

react-context