将组件作为道具传递时在 Flow 中键入 React 组件

Question

我想将一个 React 组件作为输入道具传递给另一个 React 组件。我试图将它引用为 React.Component 但是当我在渲染方法中使用传递的组件时出现错误。这就是我编写流程代码的方式。

/* @flow */

import React, { Component } from 'react';
import ReactDOM from 'react-dom';

const Input = props => <div>Yo</div>

type DefaultProps = {
  InputComponent: Input
};

type Props = {
  InputComponent: React.Component<*, *, *>
};

class App extends Component<DefaultProps, Props, void> {
  static defaultProps = {
    InputComponent: Input
  };

  props: Props;

  render() {
    const { InputComponent } = this.props

    return (
      <div>
        <InputComponent />
      </div>
    )
  }
}

ReactDOM.render(
  <App />,
  document.getElementById('root')
)

但是在 App 渲染方法中我得到了错误

React element `InputComponent` (Expected React component instead of React$Component)

我应该如何正确键入输入组件？

Answer 1

在 Flow 0.93.0 版本上，您可以执行以下操作。

从'react'导入类型{元素作为ReactElement}； 类型道具 = { 组件：反应元素 }

Answer 2

从 v0.59.0 开始，你应该使用 React.Component。例如：

/* @flow */

import React from 'react';

const Input = props => <div>Yo</div>

type Props = {
  InputComponent: React.Component<*, *>
};

class App extends React.Component<Props, void> {
  static defaultProps = {
    InputComponent: Input
  };

  render() {
    const { InputComponent } = this.props

    return (
      <div>
        <InputComponent />
      </div>
    )
  }
}

Here is a working example 为 0.59.0。如cmets中所述，有a description of the changes here。

:: v0.59.0 之前 ::

您应该使用ReactClass<*> 而不是React.Component。

这里是working example，文档是here！

/**
 * Type of a React class (not to be confused with the type of instances of a
 * React class, which is the React class itself). A React class is any subclass
 * of React$Component. We make the type of a React class parametric over Config,
 * which is derived from some of the type parameters (DefaultProps, Props) of
 * React$Component, abstracting away others (State); whereas a React$Component
 * type is useful for checking the definition of a React class, a ReactClass
 * type (and the corresponding React$Element type, see below) is useful for
 * checking the uses of a React class. The required constraints are set up using
 * a "helper" type alias, that takes an additional type parameter C representing
 * the React class, which is then abstracted with an existential type (*). The *
 * can be thought of as an "auto" instruction to the typechecker, telling it to
 * fill in the type from context.
 */
type ReactClass<Config> = _ReactClass<*, *, Config, *>;
type _ReactClass<DefaultProps, Props, Config: $Diff<Props, DefaultProps>, C: React$Component<DefaultProps, Props, any>> = Class<C>;