【发布时间】:2021-11-19 18:07:36
【问题描述】:
一个 invalid hook 错误发生在我的 react-router 引起的反应应用程序中,但我似乎无法检测到它来自哪里。完整的错误如下:
Error: Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:
1. You might have mismatching versions of React and the renderer (such as React DOM)
2. You might be breaking the Rules of Hooks
3. You might have more than one copy of React in the same app
See https://reactjs.org/link/invalid-hook-call for tips about how to debug and fix this problem.
我没有 React 版本不匹配,也不是由上述任何原因引起的错误(不能肯定,但我没有)。我关注了 react-router 文档here。我知道我搞砸了,但我不知道在哪里。
以下是必要的组件,从入口文件开始。
index.js
import React from "react";
import ReactDOM from "react-dom";
import { BrowserRouter } from "react-router-dom";
import {
ApolloProvider,
ApolloClient,
createHttpLink,
InMemoryCache,
} from "@apollo/client";
import { setContext } from "@apollo/client/link/context";
import {AUTH_TOKEN} from "./constants";
import App from "./components/App";
import "./styles/index.css";
const httpLink = createHttpLink({ uri: "http://localhost:4000" });
const authLink = setContext((_, { headers }) => {
const token = localStorage.getItem(AUTH_TOKEN);
return {
...headers,
authorization: token ? `Bearer ${token}` : "",
};
});
/*Instantiates Apollo client and connect to GraphQL server.
This will take the server link and an instantiation of the cache funtionality*/
const client = new ApolloClient({
link: authLink.concat(httpLink),
cache: new InMemoryCache(),
});
ReactDOM.render(
<BrowserRouter>
<ApolloProvider client={client}>
<React.StrictMode>
<App />
</React.StrictMode>
</ApolloProvider>
</BrowserRouter>,
document.getElementById("root")
);
App.js
import React from "react";
import LinkList from "./LinkList";
import CreateLink from "./CreateLink";
import Header from "./Header";
import Login from './Login';
import { Routes, Route } from "react-router-dom";
import "../styles/App.css";
function App() {
return (
<div className="center w85">
<Header />
<div className="ph3 pv1 background-gray">
<Routes>
<Route path="/" element={<LinkList/>} />
<Route path="/create" element={<CreateLink/>} />
<Route path="/login" element={<Login/>} />
</Routes>
</div>
</div>
);
}
export default App;
Header.js
import React from "react";
import { useNavigate, Link } from "react-router-dom";
import { AUTH_TOKEN } from "../constants";
export default function Header() {
const history = useNavigate();
const authToken = localStorage.getItem(AUTH_TOKEN);
return (
<div className="flex pa1 justify-between nowrap orange">
<div className="flex flex-fixed black">
<div className="fw7 mr1">Hacker News</div>
<Link to="/" className="ml1 no-underline black">
new
</Link>
<div className="ml1">|</div>
<Link to="/top" className="ml1 no-underline black">
top
</Link>
<div className="ml1">|</div>
<Link to="/search" className="ml1 no-underline black">
search
</Link>
{authToken && (
<div className="flex">
<div className="ml1">|</div>
<Link to="/create" className="ml1 no-underline black">
submit
</Link>
</div>
)}
</div>
<div className="flex flex-fixed">
{authToken ? (
<div
className="ml1 pointer black"
onClick={() => {
localStorage.removeItem(AUTH_TOKEN);
history.push(`/`);
}}
>
logout
</div>
) : (
<Link to="/login" className="ml1 no-underline black">
login
</Link>
)}
</div>
</div>
);
}
LinkList.js
import React from "react";
import { useQuery, gql } from "@apollo/client";
import Link from "./Link";
const LinkList = () => {
const FEED_QUERY = gql`
{
feed {
id
links {
id
createdAt
url
description
}
}
}
`;
const { loading, error, data } = useQuery(FEED_QUERY);
if (loading) return <p style={{padding: 20, textAlign:"center"}}>Loading...</p>;
if (error) console.log(error);
return (
<div>
{data &&
data.feed.links.map((link) => <Link key={link.id} link={link} />)}
</div>
);
};
export default LinkList;
CreateLink.js
import React, { useState } from "react";
import { useMutation, gql } from "@apollo/client";
import { useNavigate } from "react-router-dom";
export default function CreateLink() {
const [formState, setFormState] = useState({ description: "", url: "" });
const history = useNavigate();
const CREATE_LINK_MUTATION = gql`
mutation PostMutation($url: String!, $description: String!) {
post(url: $url, description: $description) {
id
createdAt
url
description
}
}
`;
const [createLink] = useMutation(CREATE_LINK_MUTATION, {
variables: {
description: formState.description,
url: formState.url,
},
onCompleted: () => history.push("/")
});
return (
<div>
<form
onSubmit={(e) => {
e.preventDefault();
createLink();
}}
>
<div className="flex flex-column mt3">
<input
type="text"
className="mt2"
placeholder="A description for the link"
onChange={(e) =>
setFormState({
...formState,
description: e.target.value,
})
}
value={formState.description}
/>
<input
className="mb2"
value={formState.url}
onChange={(e) =>
setFormState({
...formState,
url: e.target.value,
})
}
type="text"
placeholder="The URL for the link"
/>
</div>
<button type="submit">Submit</button>
</form>
</div>
);
}
Login.js
import React, { useState } from "react";
import { useNavigate } from "react-router-dom";
import { gql, useMutation } from "@apollo/client";
import { AUTH_TOKEN } from '../constants';
export default function Login() {
let history = useNavigate();
const [formState, setFormState] = useState({
login: true,
email: "",
password: "",
name: "",
});
const SIGNUP_MUTATION = gql`
mutation SignupMutation(
$email: string
$password: string
$name: string
) {
signup(email: $email, password: $password, name: $name) {
token
user {
name
email
}
}
}
`;
const [signup] = useMutation(SIGNUP_MUTATION, {
variables: {
email: formState.email,
password: formState.password,
name: formState.password,
},
onCompleted: ({ signup }) => {
localStorage.setItem(AUTH_TOKEN, signup.token);
history.push("/create");
},
});
const LOGIN_MUTATION = gql`
mutation LoginMutation($email: string, $password: string) {
login(email: $email, password: $password) {
token
}
}
`;
const [login] = useMutation(LOGIN_MUTATION, {
variables: {
email: formState.email,
password: formState.password,
},
onCompleted: ({ login }) => {
localStorage.setItem(AUTH_TOKEN, signup.token);
history.push("/");
},
});
return (
<div>
<h4 className="mv3">{formState.login ? "Login" : "Sign Up"}</h4>
<div className="flex flex-column">
{!formState.login && (
<input
value={formState.name}
onChange={(e) =>
setFormState({
...formState,
name: e.target.value,
})
}
type="text"
placeholder="Your name"
/>
)}
<input
value={formState.email}
onChange={(e) =>
setFormState({
...formState,
email: e.target.value,
})
}
type="text"
placeholder="Your email address"
/>
<input
value={formState.password}
onChange={(e) =>
setFormState({
...formState,
password: e.target.value,
})
}
type="password"
placeholder="Choose a safe password"
/>
</div>
<div className="flex mt3">
<button
className="pointer mr2 button"
onClick={() => (formState.login ? login : signup)}
>
{formState.login ? "login" : "create account"}
</button>
<button
className="pointer button"
onClick={(e) =>
setFormState({
...formState,
login: !formState.login,
})
}
>
{formState.login
? "need to create an account?"
: "already have an account?"}
</button>
</div>
</div>
);
}
根据项目中的包安装的 React 版本:
react-apollo-integration@0.1.0 c:\projects\react-apollo-integration\frontend
+-- @apollo/client@3.4.17
| `-- react@17.0.2 deduped
+-- @testing-library/react@11.2.7
| +-- react-dom@17.0.2 deduped
| `-- react@17.0.2 deduped
+-- react-dom@17.0.2
| `-- react@17.0.2 deduped
+-- react-scripts@4.0.3
| `-- react@17.0.2 deduped
`-- react@17.0.2
【问题讨论】:
-
看起来您没有包含 Header 和 Link 组件。就个人而言,除了可能的版本不匹配外,我没有看到任何关于 hooks 的使用问题。如果警告有有意义的堆栈跟踪,您可以尝试遵循它
-
@max 我已经添加了
Header组件。Link组件只是一个带有属性的普通组件。没有什么有趣的事情发生。 -
好吧,还是什么都没有。在您的位置上,我会尝试对您的应用程序的某些部分进行评论并运行它,直到您没有收到错误(一种二进制搜索)。然后您可以缩小问题所在的范围
-
您是否尝试将您的 httpLink 实例移动到您的 authLink 函数范围内?显然它是在函数范围之外调用的唯一可能的钩子。
-
是否有任何迹象表明您的代码中哪个钩子受到了指责?你能检查
react、react-dom和react-router-dom的安装版本吗?在您的项目目录中运行npm list react react-dom react-router-dom。
标签: javascript reactjs react-router