react-select 使用 TypeScript 的异步加载选项

Question

我正在将现有的 React 应用程序转换为打字稿，但我无法让 react-select 异步 loadOptions 正确解析为打字稿。

export type userType = {
    loginId: string,
    firstName: string,
    lastName: string,
    email: string,
}

<AsyncSelect
    id={n.id}
    name={n.id}
    isClearable={true}
    onBlur={handleBlur}
    onChange={onChange}
    placeholder={"Search by name, email or login ID"}
    value={input}
    className={input_class}
    loadOptions={loadOptions}
/>


const loadOptions = async (inputText: string, callback: any) => {
    axios.get(`myAPI_URI`)
        .then((response) => {
            let data: userType[] = response.data.results;
            return data.map(result => {
                return labelFormatter(result)
            })
        });
}

const labelFormatter = (i: any) => {
    return {
        label: i.loginId + ' - ' + i.firstName + ' ' + i.lastName + ' - ' + i.email,
        value: i.loginId,
    }
}

错误是

    No overload matches this call.
Overload 1 of 2, '(props: Props<filteredOptionType, false, GroupTypeBase<filteredOptionType>> | Readonly<Props<filteredOptionType, false, GroupTypeBase<...>>>): Async<...>', gave the following error.
    Type '(inputText: string, callback: any) => Promise<void>' is not assignable to type '(inputValue: string, callback: (options: readonly (filteredOptionType | GroupTypeBase<filteredOptionType>)[]) => void) => void | Promise<...>'.
    Type 'Promise<void>' is not assignable to type 'void | Promise<readonly (filteredOptionType | GroupTypeBase<filteredOptionType>)[]>'.
        Type 'Promise<void>' is not assignable to type 'Promise<readonly (filteredOptionType | GroupTypeBase<filteredOptionType>)[]>'.
        Type 'void' is not assignable to type 'readonly (filteredOptionType | GroupTypeBase<filteredOptionType>)[]'.
Overload 2 of 2, '(props: Props<filteredOptionType, false, GroupTypeBase<filteredOptionType>>, context: any): Async<filteredOptionType, false, GroupTypeBase<...>>', gave the following error.
    Type '(inputText: string, callback: any) => Promise<void>' is not assignable to type '(inputValue: string, callback: (options: readonly (filteredOptionType | GroupTypeBase<filteredOptionType>)[]) => void) => void | Promise<...>'.  TS2769

我不明白我需要在哪里声明 return 类型才能使 loadOptions 正常工作。

Answer 1

如果那是您的 loadOptions 函数的实际代码，那么它有几个问题：

它没有 return 任何有意义的值（它 return 是 undefined，占 async 它有 return 类型 Promise<void>)
它没有副作用

从实际的角度来看，它没有任何用处，只是丢弃了响应数据。

要解决此问题，您可以采用以下方法之一：

Return 有用的东西。然后你必须注释函数的 return 类型：

import { OptionTypeBase } from "react-select/src/types"

const labelFormatter = (i: userType): OptionTypeBase => {
  return {
      label: i.loginId + ' - ' + i.firstName + ' ' + i.lastName + ' - ' + i.email,
      value: i.loginId,
  }
}

// add `return` keyword
const loadOptions = async (
    inputText: string, 
    callback: any
): Promise<OptionTypeBase[]> => {
    return axios.get(`myAPI_URI`)
        .then((response) => {
            let data: userType[] = response.data.results;
            return data.map(result => {
                return labelFormatter(result)
            })
        });
}

// or remove curly braces
const loadOptions = async (
    inputText: string, 
    callback: any
): Promise<OptionTypeBase[]> => 
    axios.get(`myAPI_URI`)
        .then((response) => {
            let data: userType[] = response.data.results;
            return data.map(result => {
                return labelFormatter(result)
            })
        });

或执行副作用：

// no `async` keyword. and using callback inside the function body
const loadOptions = (
    inputText: string,
    callback: (options: OptionTypeBase[]) => void
): void => {
    axios.get(`myAPI_URI`).then((response) => {
        let data: userType[] = response.data.results;
        callback(data.map((result) => {
            return labelFormatter(result);
        }))
    });
};

react-select 使用 TypeScript 的异步加载选项

react-select async loadOptions with TypeScript

javascript

typescript

reactjs

react-select