javascript - 收到错误 "Cannot update a component while rendering a different component"。实现我正在尝试的正确方法是什么？

Question

如标题所述，我目前收到以下错误:无法更新组件( HomePage )同时呈现不同的组件( Query )。
我对 React 还很陌生，即使我认为我知道我正在打破的规则(只在顶层使用钩子(Hook)来保持它们被调用的顺序)我不确定如何实现我的目标'正在尝试另一种方式。
如果我们在后端没有任何采访，目标是 setPreLaunch(true)。这段代码完成了这项工作，但它会引发错误。我尝试将钩子(Hook)作为 Prop 发送到 Interviews 组件并在那里处理它，但遇到了同样的错误。
这是有问题的代码:

import React, { useState } from "react";
import Interviews from "../../components/Interviews";
import Query from "../../components/Query";
import INTERVIEWS_QUERY from "../../queries/interviews/interviews";
import {
  Row,
  Col,
  Button,
  InputGroup,
  FormControl,
  Form,
} from "react-bootstrap";
import Filters from "../../components/Filters";
import jsonp from "jsonp";
import queryString from "query-string";

const HomePage = () => {
  const [genre, setGenre] = useState(["Any"]);
  const [authorHistory, setAuthorHistory] = useState(["Any"]);
  const [preLaunch, setPreLaunch] = useState(false);
  const [emailEntered, setEmailEntered] = useState("");
  const [emailMessage, setEmailMessage] = useState("");

  if (!preLaunch) {
    return (
      <div>
        <Row id="home-banner-container">
          <Col md={12}>
            {" "}
            <h1 id="home-main-heading" className="text-center">
              Text
            </h1>
            <p id="home-sub-heading" className="text-center">
              Text
            </p>
          </Col>
        </Row>
        <Row>
          <Col md={3}>
            <Filters
              genre={genre}
              setGenre={setGenre}
              authorHistory={authorHistory}
              setAuthorHistory={setAuthorHistory}
            />
            <div className="contact-blurb">
              Text
            </div>
            <Button variant="primary" className="contact-blurb-btn">
              Contact
            </Button>{" "}
          </Col>
          <Col md={9}>
            <Query query={INTERVIEWS_QUERY}>
              {({ data: { interviews } }) => {
                if (interviews.length < 1) {
                  setPreLaunch(true);
                } else {
                  setPreLaunch(false);
                }
                return (
                  <Interviews
                    interviews={interviews}
                    genreFilter={genre}
                    authorHistoryFilter={authorHistory}
                  />
                );
              }}
            </Query>
          </Col>
        </Row>
      </div>
    );
  } else {
    return (
      <div>
        <Row id="home-banner-container">
          <Col md={12}>
            {" "}
            <h1 id="home-main-heading" className="text-center">
              Text
            </h1>
            <p id="home-sub-heading" className="text-center">
              Text
            </p>
          </Col>
        </Row>
        <Row>
          <Col md={{ span: 6, offset: 3 }}>
            <Form
              onSubmit={subscribeToNewsLetter}
              className="prelaunch-email-form"
            >
              <InputGroup className="mb-3">
                <FormControl
                  placeholder="Email Address"
                  aria-label="Email Address"
                  type="email"
                  onChange={(e) => setEmailEntered(e.target.value)}
                  value={emailEntered}
                  className="prelaunch-email-input"
                />
                <InputGroup.Append>
                  <Button
                    variant="outline-secondary"
                    type="Submit"
                    className="prelaunch-email-btn"
                  >
                    Keep Me Updated
                  </Button>
                </InputGroup.Append>
              </InputGroup>
              <p>{emailMessage}</p>
            </Form>
          </Col>
        </Row>
        <Row>
          <Col md={3}></Col>
          <Col md={9}>
            <Query query={INTERVIEWS_QUERY}>
              {({ data: { interviews } }) => {
                if (interviews.length < 1) {
                  setPreLaunch(true);
                } else {
                  setPreLaunch(false);
                }
                return (
                  <Interviews
                    interviews={interviews}
                    genreFilter={genre}
                    authorHistoryFilter={authorHistory}
                  />
                );
              }}
            </Query>
          </Col>
        </Row>
      </div>
    );
  }
};

export default HomePage;

编辑
这是英雄推荐的带有查询回调的更新主页代码。

  const [genre, setGenre] = useState(["Any"]);
  const [authorHistory, setAuthorHistory] = useState(["Any"]);
  const [preLaunch, setPreLaunch] = useState(false);
  const [emailEntered, setEmailEntered] = useState("");
  const [emailMessage, setEmailMessage] = useState("");

  const onInterviewsReady = (interviews) => {
    setPreLaunch(interviews.length < 1);
  };

  const myQuery = (
    <Query
      query={INTERVIEWS_QUERY}
      onInterviewsReady={(i) => onInterviewsReady(i)}
    >
      {({ data: { interviews } }) => {
        return (
          <Interviews
            interviews={interviews}
            genreFilter={genre}
            authorHistoryFilter={authorHistory}
          />
        );
      }}
    </Query>
  );

  ...

这是完整的查询文件:

import React from "react";
import { useQuery } from "@apollo/react-hooks";

const Query = ({ children, query, id, onInterviewsReady }) => {
  const { data, loading, error } = useQuery(query, {
    variables: { id: id },
  });

  if (loading) return <p>Loading...</p>;
  if (error) return <p>Error: {JSON.stringify(error)}</p>;
  if (onInterviewsReady) {
    onInterviewsReady(data.interviews);
  }
  return children({ data });
};

export default Query;

使用此更新的代码，结果是相同的。一个正常运行的网站，它会抛出与以前相同的错误。

Answer 1

如果访谈是在 Query 内异步获取的，一个简单的解决方法可能是:

引入新的回调 Prop onInterviewsReady到Query组件

让 Query面试准备好后立即调用此回调(useEffect)

不使用效果仍然会导致外部组件的状态在渲染时发生更改 Query ，产生警告

通过宿主组件实现回调HomePage具有类似 const onInterviewsReady = interviews => setPreLaunch(interviews.length < 1); 的功能并将其传递给 Query

如果您面临不必要的重新渲染，您可能希望通过修改任何一个来确保您的回调引用是稳定的

主机组件( HomePage ):将回调定义包装在 useCallback 中在将其传递给消费组件之前

消费组件( Query ):将传递的回调 Prop 包装在 useRef 中并在效果中调用 ref 的当前值而不是 prop 的值