On Jan 14, 2013, at 10:40 PM, Brandon Benvie wrote:
> The proxy target is important because it specifies some invariants about the
> proxy (typeof, builtin brand, behavior of forwarding for unspecified traps,
> values of internal properties like [[DateValue]], [[NumberValue]], etc.).
>
Sure, but the target still exists. I't just created implicitly (as new
Object()) if not provided.
1. Explicit target:
var p = new Proxy(handler, {x: 10});
2. Implicit target:
var p = new Proxy(handler); // which is the same as:
var p = new Proxy(handler, {});
Then only difference from the current API, that the target is the second
argument to the Proxy constructor which allows to ditch cases like: var p = new
Proxy({}, handler), where you're forced always pass this empty object.
But, here can be the trade-off, having this target as the first argument,
because it correlates with the methods from ES5 like var o =
Object.defineProperties({}, descriptors);.
Dmitry
>
> On Tue, Jan 15, 2013 at 1:09 AM, Andrea Giammarchi
> <[email protected]> wrote:
> and `this` is the handler, not the target ...
>
> var
> handler,
> target = {test:123},
> proxy = new Proxy(target, handler = {
> get: function ($target, key) {
> alert($target === target); // true
> alert(this === handler); // true
> return $target[key];
> }
> })
> ;
> alert(proxy.test); // 123
>
> and no, I don;'t think everyone gonna proxy empty objects but if that's the
> case you want that because either you are looking for a singleton, otherwise
> what's the point to have same target per each new handler? Your concern is
> the othr way round too, isn't it?
>
> If you use new Proxy you want a different target, I guess, otherwise you are
> most likely looking for same handler, different targets, which makes more
> sense, imho
>
> new Proxy({/*fresh new target*/}, sameHandler)
>
>
>
>
>
> On Mon, Jan 14, 2013 at 9:55 PM, Dmitry Soshnikov
> <[email protected]> wrote:
>
> On Jan 14, 2013, at 9:51 PM, Andrea Giammarchi wrote:
>
>> uhm, you might be slightly behind current specs ... these changed proxy
>> quite a lot so that first argument is the target, and second argument is the
>> behavior.
>>
>> var myProxy = new Proxy(target, handler);
>>
>
> Oh, I'm aware about current pre-spec MDC article and API. And this is why
> saying. In most use-cases you probably wanna proxy an empty object, and this
> is why in current API you end up in code like this:
>
> var p = new Proxy({}, handler);
>
> And I'm saying about these "{}" always as the first argument.
>
> Dmitry
>
>> at least that's how Firefox implemented it right now :D
>>
>> var
>> target = {test:123},
>> proxy = new Proxy(target, {
>> get: function ($target, key) {
>> alert($target === target); // true
>> return $target[key];
>> }
>> })
>> ;
>> alert(proxy.test); // 123
>>
>>
>> On Mon, Jan 14, 2013 at 9:32 PM, Dmitry Soshnikov
>> <[email protected]> wrote:
>> Hello,
>>
>> Don't know whether it was mentioned/asked before (sorry if so), but just a
>> note: probably it makes more sense making the target argument as optional
>> and the second one in the Proxy constructor's API.
>>
>> Proxy(handler[, target]):
>>
>> 1. If target is undefined, let the target be new Object();
>> ...
>>
>> In this case we'll cover (probably the most used) use-case of direct-proxies:
>>
>> var p = new Proxy({
>> get: function(target, name, value) {
>> ...
>> }
>> });
>>
>> Thanks,
>> Dmitry
>> _______________________________________________
>> es-discuss mailing list
>> [email protected]
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>
>
>
> _______________________________________________
> es-discuss mailing list
> [email protected]
> https://mail.mozilla.org/listinfo/es-discuss
>
>
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
