Typescript使用通用参数/返回类型来响应无状态函数 [英] Typescript React stateless function with generic parameter/return types
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问题描述
如何基于参数或外部配置在React无状态组件中定义通用类型?
How to define generic type in React stateless components based on parameter, or outside configuration?
示例组件:
interface IProps<V> {
value: V;
doSomething: (val: V) => void;
}
const Comp: React.SFC<IProps<number>> = <T extends number>({
value: T,
doSomething
}) => {
return <div />;
}
上面的示例将起作用,但仅将数字作为值.
Above example will work, but only with numbers as values.
可以进行升级以达到以下目的:
Is possible to do upgrade to achieve something like:
const Comp: React.SFC<IProps<??>> = <?? extends string | number>({
value, /* of type ?? */
doSomething
}) => {
return <div />;
}
这样,当我们使用component时,我们可以决定我们想要的数字还是字符串.
So that we can decide whatever we want numbers, or strings when using component.
所需用法:
// This should setup generic type to string
<Comp value="string" ... />
// Or number
<Comp value={123} ... />
// Should be compilation error as we cannot use * on 'text' * 5
<Comp value="text" doSomething={val => val * 5} />
应执行与function
相同的工作:
function Comp <T>({value, doSomething}: IProps<T>) { ... }
SFC类型具有定义:
SFC Type has definition:
interface SFC<P> {
(props: P & { children?: ReactNode }, context?: any): ReactElement<any>;
...
}
推荐答案
我能够在TS 2.3中做到这一点.关键是要对该组件的内部"和外部"使用两种类型.
I was able to do this in TS 2.3. The point is to use 2 types for "inside" and "outside" of that component.
interface IProps<V> {
value: V;
doSomething(val: V): void;
}
// type "inside" component
function _Comp<T>(props: IProps<T>) {
return <div />;
}
// type for "outside" of component
interface GenericsSFC extends React.SFC<any> {
<T>(props: IProps<T> & { children?: React.ReactNode }, context?: any): JSX.Element;
}
const Comp = _Comp as GenericsSFC;
// dont type check: v is of type "hey"
<Comp value={"hey"} doSomething={v => v - 1} />;
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