Re: ClojureScript can't call JavaScript functions relying on `this`

2011-08-29 Thread Chouser 
On Sun, Aug 28, 2011 at 9:22 PM, Kevin Lynagh klyn...@gmail.com wrote:
 I am having trouble using ClojureScript to call JavaScript functions
 that exploit prototype injection.
 If I'm reading `defmethod :emit invoke` correctly,

    
 https://github.com/clojure/clojurescript/blob/master/src/clj/cljs/compiler.clj#L513

 ClojureScript always seems to compile f(x) JavaScript calls as

    f.call(null, x)

 which trip up any functions that rely on `this` to have certain
 properties.
 I have two questions:

 1) why are function calls compiled to the `f.call(null, ...)` form
 rather than just `f(...)`? Is it to support the Closure Compiler?

 2) What is the appropriate way to use JavaScript functions that rely
 on `this`?
 Is there some way to emit `f.call(f, ...)`, or do I need to use `(js*
 f(...))`?

 For reference, here is a minimal JavaScript example of the JavaScript
 prototype injection pattern:

    var p_injection = function(){};
    p_injection.one = function(){ return 1; };

    var MyClass = function(){};

    var x = new MyClass();
    x.two = function(){  return this.one() + 1; };
    x.__proto__ = p_injection;
    x.two(); // 2
    x.two.call(null); // error, object has no method one()

Have you tried calling the method using the interop form?

(. x (two))

--Chouser

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Re: ClojureScript can't call JavaScript functions relying on `this`

2011-08-29 Thread Kevin Lynagh 
Chouser,

Yes, that does it---I didn't even think about my use of (apply js/f
args), thanks!

Is there a way to use the interop form with variable-arity JavaScript
functions without using `apply`?
This issue came up with my ClojureScript wrapper for D3; I'm using
this macro

(defmacro shim [name]
  Define a proxy to native D3 method
  `(defn ~name [sel#  args#]
 (apply (. sel# ~name) args#)))

to define proxy functions.
If I can't use `apply` because of the `this = null` problem, do I have
to write out a case for each arity?

thanks,
kevin

On Aug 29, 6:24 am, Chouser chou...@gmail.com wrote:
 On Sun, Aug 28, 2011 at 9:22 PM, Kevin Lynagh klyn...@gmail.com wrote:
  I am having trouble using ClojureScript to call JavaScript functions
  that exploit prototype injection.
  If I'm reading `defmethod :emit invoke` correctly,

     https://github.com/clojure/clojurescript/blob/master/src/clj/cljs/com...

  ClojureScript always seems to compile f(x) JavaScript calls as

     f.call(null, x)

  which trip up any functions that rely on `this` to have certain
  properties.
  I have two questions:

  1) why are function calls compiled to the `f.call(null, ...)` form
  rather than just `f(...)`? Is it to support the Closure Compiler?

  2) What is the appropriate way to use JavaScript functions that rely
  on `this`?
  Is there some way to emit `f.call(f, ...)`, or do I need to use `(js*
  f(...))`?

  For reference, here is a minimal JavaScript example of the JavaScript
  prototype injection pattern:

     var p_injection = function(){};
     p_injection.one = function(){ return 1; };

     var MyClass = function(){};

     var x = new MyClass();
     x.two = function(){  return this.one() + 1; };
     x.__proto__ = p_injection;
     x.two(); // 2
     x.two.call(null); // error, object has no method one()

 Have you tried calling the method using the interop form?

 (. x (two))

 --Chouser

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ClojureScript can't call JavaScript functions relying on `this`

2011-08-28 Thread Kevin Lynagh 
I am having trouble using ClojureScript to call JavaScript functions
that exploit prototype injection.
If I'm reading `defmethod :emit invoke` correctly,


https://github.com/clojure/clojurescript/blob/master/src/clj/cljs/compiler.clj#L513

ClojureScript always seems to compile f(x) JavaScript calls as

f.call(null, x)

which trip up any functions that rely on `this` to have certain
properties.
I have two questions:

1) why are function calls compiled to the `f.call(null, ...)` form
rather than just `f(...)`? Is it to support the Closure Compiler?

2) What is the appropriate way to use JavaScript functions that rely
on `this`?
Is there some way to emit `f.call(f, ...)`, or do I need to use `(js*
f(...))`?

For reference, here is a minimal JavaScript example of the JavaScript
prototype injection pattern:

var p_injection = function(){};
p_injection.one = function(){ return 1; };

var MyClass = function(){};

var x = new MyClass();
x.two = function(){  return this.one() + 1; };
x.__proto__ = p_injection;
x.two(); // 2
x.two.call(null); // error, object has no method one()




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