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I think that's a pretty poor practice. It's actually counter to central idea of this article; that you should think with the language features. In situations li

by notb 14y ago

I think that's a pretty poor practice. It's actually counter to central idea of this article; that you should think with the language features. In situations like the one above, if you dont want to lose the context of "this" you can explicitly bind an object to be this and return the new bound function. See underscore's bind(). Its a little more verbose and clunky but it saves you from tossing out modular code.

yesbabyyes 14y ago
And of course, in CoffeeScript you would just use the fat arrow: somethingElse = render: => # do some rendering
- Cushman 14y ago
  Careful, that's not the same as (->).bind(somethingElse). => binds to the current value of this at execution-- in that function, @ will compile to `var _this = this`, not `somethingElse` as we'd expect. I just tested and it looks like you can hack it by doing _this = somethingElse = render: => @renderMe # @ is somethingElse but that is definitely a bug.
  - raganwald 14y ago
    I've written some transpilers, and I nearly always use a "magic variable" like __this_12345 just to prevent problems like--umm--this. If every single one you use has a quasi-random number or string appended, a lot of headaches melt away.
Xcelerate 14y ago
I'm not so sure it's poor practice. Rich Hickey makes an excellent point about not confounding data and functions. And Javascript provides excellent structures for avoiding mutability altogether (if one wishes to) thanks to first-class functions. Javascript was always an amalgam of C-syntax, object-oriented "ideas", and functional "ideas". To "think with the language features" is to tie to together two disparate programming paradigms that in my opinion perform better independently than in combination. So I just happen to focus more on the functional aspects of Javascript (and CoffeeScript provides syntactic support to make this much easier).
- MatthewPhillips 14y ago
  Not poor practice in that Functional Programming is poor practice (it's great practice!). Poor practice in that JS is object oriented and JS engines optimize for OO style, see https://developers.google.com/v8/design https://developers.google.com/v8/design for example. So avoid `this` if you don't care how fast your code runs.
MatthewPhillips 14y ago
> See underscore's bind() Better, just use Function.prototype.bind, 0 bytes gzipped with Vanilla JS.

by notb 14y ago

yesbabyyes 14y ago

And of course, in CoffeeScript you would just use the fat arrow: somethingElse = render: => # do some rendering

Cushman 14y ago
Careful, that's not the same as (->).bind(somethingElse). => binds to the current value of this at execution-- in that function, @ will compile to `var _this = this`, not `somethingElse` as we'd expect. I just tested and it looks like you can hack it by doing _this = somethingElse = render: => @renderMe # @ is somethingElse but that is definitely a bug.
- raganwald 14y ago
  I've written some transpilers, and I nearly always use a "magic variable" like __this_12345 just to prevent problems like--umm--this. If every single one you use has a quasi-random number or string appended, a lot of headaches melt away.

Xcelerate 14y ago

I'm not so sure it's poor practice. Rich Hickey makes an excellent point about not confounding data and functions. And Javascript provides excellent structures for avoiding mutability altogether (if one wishes to) thanks to first-class functions. Javascript was always an amalgam of C-syntax, object-oriented "ideas", and functional "ideas". To "think with the language features" is to tie to together two disparate programming paradigms that in my opinion perform better independently than in combination. So I just happen to focus more on the functional aspects of Javascript (and CoffeeScript provides syntactic support to make this much easier).

MatthewPhillips 14y ago
Not poor practice in that Functional Programming is poor practice (it's great practice!). Poor practice in that JS is object oriented and JS engines optimize for OO style, see https://developers.google.com/v8/design https://developers.google.com/v8/design for example. So avoid `this` if you don't care how fast your code runs.

MatthewPhillips 14y ago

> See underscore's bind() Better, just use Function.prototype.bind, 0 bytes gzipped with Vanilla JS.