On 19/06/16 02:27, Carsten Haitzler wrote: > On Fri, 17 Jun 2016 09:41:39 +0100 Tom Hacohen <t...@osg.samsung.com> said: > >> On 17/06/16 03:28, Carsten Haitzler wrote: >>> On Thu, 16 Jun 2016 19:13:20 +0100 Tom Hacohen <t...@osg.samsung.com> said: >>> >>>> On 03/06/16 20:17, Cedric BAIL wrote: >>>> <snip> >>>>>>> also promises should become eo objects with event cb's >>>>>>> so they work just like everything else. i can ref, unref, delete and >>>>>>> whatever them like everything else. >>>>> >>>>> As said above, this does work. Example with event : >>>>> eo_promise = efl_file_set(image, "toto.jpg", NULL); >>>>> eo_event_callback_array_add(eo_promise, promise_callbacks1(), NULL); >>>>> eo_event_callback_array_add(eo_promise, promise_callbacks2(), NULL); >>>>> >>>>> In this 3 lines, there is already 2 case in which that fail. First if, >>>>> the object is done before the callback is set, data are lost and there >>>>> is no way to get any event. Ofcourse, we can override the behavior of >>>>> events on this eo_promise completely. Now let's imagine, that we >>>>> actually do always store the events, so that everytime someone >>>>> register a callback we can send the event. Still you can't auto del >>>>> the object at any point in time, you have to force the user to >>>>> implement the eo_del and to always provide both a then and cancel >>>>> callback. >>>>> >>>>> Other possibility, it is an event on the object itself. >>>>> eo_event_callback_array_add(image, promise_callbacks1(), NULL); >>>>> efl_file_set(image, "toto.jpg", NULL); >>>>> eo_event_callback_array_add(image, promise_callbacks2(), NULL); >>>>> >>>>> Same again, this can not work. The first group of event handler, >>>>> promise_callbacks1(), may actually be triggered by a previously >>>>> running promise on the object, so you have to first forcefully stop >>>>> the previous operation. This would add complexity. And still the >>>>> second callback has the same issue as the previous case, if it is a >>>>> normal eo event, it could have been triggered before any callback get >>>>> registered and the event be lost... Same story short, doesn't work. >>>>> >>>> >>>> I'm currently reading through the thread, and I didn't see anything >>>> mentioned about this other than a casual remark you made, so just wanted >>>> to make it crystal clear regarding implementing it as an Eo object. >>>> The whole point/magic of inheritance is that you can and are supposed to >>>> override functions if needed. Overriding callback add to call the >>>> callback immediately upon addition (if already done) is how I would >>>> implement promise callbacks. It's clean, easy and as intended. This is >>>> definitely not a problem. >>> >>> just for convenience i think having a special eo_promise_then(obj, cb1, cb2, >>> data); may be best as its the simplest and is not pretending to ADD a cb in >>> the name. it sets it explicitly. this needs special treatment like the eo >>> event callbacks of course. >>> >>> but using an eo event is possible by override indeed, but here is the issue. >>> you have to wait until either "then" or "else" or both are set. since you >>> set one then set another... you will have to always add one of them as a >>> NULL or dummy cb just to do this. having a single method/func set both >>> makes more sense. in fact this likely needs manual binding/.handling per >>> language anyway. i'm really only thinking of eo events for EXTRA features >>> like progress events on a promise that happen before the success/fail cb's >>> above. >>> >>> >> >> This is explained better in my reply to the initial post of this thread, >> but essentially you don't. What you are missing, and why life-cycle can >> be pretty broken, and why this doesn't matter is that you can register a >> few "then" and a few "cancel" in promises. That is actually the power of >> promises, that you can chain them and use them for a few things. This is >> dealt with nicely. See the post I mentioned. > > register a few then/else cb's on the same promise? at least that should not be > possible (it should not work). on;y one else/then cb (zero or one of each). > >
Why not? Anyhow, as I said, that is very common in js land and how race and all are probably implemented. -- Tom. ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohomanageengine _______________________________________________ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel