CODEWITHSUNDEEP
typescripttypescript-typings
Rafid
Rafid

Reputation: 20179

Declaring global functions in a TypeScript module

I have a set of plain JS functions defined in my index.html function. I would like to declare those functions to be able to use them in TypeScript files. This is what I do:

declare function getHtmlBasePath(): String;
declare function fbFetchedLoginStatus(): boolean;
declare function getFbAccessToken(): String;
declare function setFbAccessToken(token: String);

However, to avoid declaring those files in every TypeScript file where they are used, I would like to define them in a separate file and import that file wherever I want. This way, I void duplicate declaration and I also get the support of the IDE if I want to do refactoring later. However, by the time I define those declarations in a TypeScript file and import them, the TypeScript compiler will assume this is a module that actually has to be imported, while it is simply a declaration file (more like a header file for an external library in C/C++).

Is there a way to have a certain TypeScript serves no purpose other than set of a declaration, i.e. when you import it, TypeScript compiler doesn't generate require statements?

Upvotes: 0

Views: 5640

Answers (2)

Amal
Amal

Reputation: 278

Export the function definition in a separate file using export keyword:

export function getHtmlBasePath(): String {
    // your code
}

TO use the function in any other typescript file, just import the function using the import keyword.

import {getHtmlBasePath} from 'filename';

filename is the name of the file where the function definition is written. After import the function you ca use the function as any other normal function.

Upvotes: 3

Tsvetan Ganev
Tsvetan Ganev

Reputation: 8826

The TypeScript compiler is smart enough not to transform those declarations into require statements. In fact, none of them will end up in your compiled JavaScript code.

Upvotes: 0

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