可重用功能类型

Question

I'm trying declare a function type and then use that in a class, and in objects, and interfaces like this:

declare function IUpdateMode(mode: Mode): void;

Then I want to use it like this:

type Foo = {
   updateMode: IUpdateMode
}


class Foo extends React.Component<any> {

    updateRedMode(mode): IUpdateMode {}

}

function updateGreenMode(mode): IUpdateMode {

}

Is this possible in typescript?

Answer 1

I think what you really want is just this:

type UpdateMode = (mode: Mode) => void

Now you can use it anywhere as you mentioned, but with some corrections:

interface IFoo { // interface instead of a type is preferable when possible (e.g. you may extend it)
   updateMode: UpdateMode
}


class Foo extends React.Component<any> implements IFoo {

    updateMode = (mode: Mode) => {}

}

const updateGreenMode: UpdateMode = (mode) => { // there is no way to restrict a classic function to type alias or interface

}