CODEWITHSUNDEEP
javascriptcoffeescriptcallable
Zaur Nasibov
Zaur Nasibov

Reputation: 22659

Callable CoffeeScript classes

Consider the following CoffeeScript class:

class Event
    trigger : (args...) =>
        ...

    bind : (args...) =>
        ...

The use case would be:

message_received = new Event()
message_received.bind(alert)                                       
message_received.trigger('Hello world!') # calls alert('Hello world')

Is there a way to write the Event class in such manner that the .trigger(...) call would have the "callable object" shortcut: 

message_received('Hello world')  # ?

Thank you!

Upvotes: 2

Views: 525

Answers (2)

shesek
shesek

Reputation: 4682

Check out https://gist.github.com/shesek/4636379. It allows you to write something like that:

Event = callable class
    trigger : (args...) =>
        ...
    bind : (args...) =>
        ...

    callable: @::trigger

Note: it relies on __proto__ (no other way to set the [[Prototype]] of functions), so you shouldn't use that if you need it to work on IE. I use it for server-side code and for intranet projects when I know users won't be using IE.

Upvotes: 1

Rob W
Rob W

Reputation: 348972

You need to return a function from the constructor, which is extended with the properties from the current instance (which in turn is inherit from Event.prototype).

class Event
    constructor : ->
        shortcut = -> shortcut.trigger(arguments...)
        for key, value of @
            shortcut[key] = value
        return shortcut

    trigger : (args...) =>
        ...

    bind : (args...) =>
        ...

Compiled result

Upvotes: 4

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