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. ------------------------------------------------------------------------------ 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
