How to declare nested functions in a TypeScript declaration source file?

Question

I'm in the process of building a declaration source file for KeyboardJS. The API is referenced from a static object (KeyboardJS) instantiated when the JavaScript file is loaded. A few of the methods of the API are nested under other methods. For example:

KeyboardJS.clear(keyCombo);

and

KeyboardJS.clear.key(key);

Here is my interface definition:

interface KeyboardJSStatic {
    enable(): void;
    disable(): void;
    activeKeys(): string[];
    on(keyCombo:string, onDownCallback?: (keyEvent: Event, keysPressed: string[], keyCombo: string) => {}, onUpCallback?: (keyEvent: Event, keysPressed: string[], keyCombo: string) => {}): KeyboardJSBinding;
    clear(keyCombo: string): void;
    clear.key(keyName: string): void;
    locale(localeName: string): KeyboardJSLocale;
    locale.register(localeName: string, localeDefinition: KeyboardJSLocale): void;
    macro(keyCombo:string , keyNames: string[]): void;
    macro.remove(keyCombo: string): void;
    key: KeyboardJSKey;
    combo: KeyboardJSCombo; 
}

The TypeScript plugin for Visual Studio 2012 is generating and error on the clear.key line, recommending a semicolon for where the period is. Has anyone built a definition file with a similar scenario? Thanks!

Once done, you are more than welcome to submit the definition file to github.com/borisyankov/DefinitelyTyped — Boris Yankov
– Boris Yankov, Commented Jan 17, 2013 at 1:26
Thanks Boris. Honestly, that was my plan all along. Great job with DefinitelyTyped! — Vincent
– Vincent, Commented Jan 17, 2013 at 16:20

Ryan Cavanaugh · Accepted Answer · 2013-01-17 00:05:30Z

9

You can declare call signatures on types like this:

interface KeyboardJSStatic {
    // ...
    clear: {
        (keyCombo: string): void; // Call signature
        key(keyName: string): void; // Method
    };
    // ...
}

var n: KeyboardJSStatic;
n.clear('a'); // OK
n.clear.key('b'); // OK

answered Jan 17, 2013 at 0:05

Ryan Cavanaugh

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1 Comment

Boris Yankov Over a year ago

Exactly. Also you can declare the whole thing as a ' interface KeyboardJsClear { }'

Fenton · Accepted Answer · 2013-01-17 09:03:58Z

2

Genius comment from Ryan. Using the same pattern as the jQuery definition you could do:

interface KeyboardJSClear {
    (keyCombo: string) : void;
    key(keyName: string): void;
}

interface KeyboardJSLocale {
    (localeName: string) : KeyboardJSLocale;
    register(localeName: string, localeDefinition: KeyboardJSLocale): void;
}

interface KeyboardJSMacro {
    (keyCombo:string , keyNames: string[]): void;
    remove(keyCombo: string): void;
}

interface KeyboardJSStatic {
    enable(): void;
    disable(): void;
    activeKeys(): string[];
    on(keyCombo:string, onDownCallback?: (keyEvent: Event, keysPressed: string[], keyCombo: string) => {}, onUpCallback?: (keyEvent: Event, keysPressed: string[], keyCombo: string) => {}): KeyboardJSBinding;
    clear: KeyboardJSClear;
    locale: KeyboardJSLocale;
    macro: KeyboardJSMacro;
    key: KeyboardJSKey;
    combo: KeyboardJSCombo; 
}

declare var KeyboardJS: KeyboardJSStatic;

KeyboardJS.clear('');
KeyboardJS.clear.key('');

edited Jan 17, 2013 at 9:03

answered Jan 16, 2013 at 23:12

Fenton

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2 Comments

ryan Over a year ago

Think about the jquery definitions. $() and $.ajax() etc

Vincent Over a year ago

Thanks guys, this was a big help.

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