Why can you can just use simple callbacks for this pattern? David
On Fri, Oct 17, 2014 at 3:04 PM, Stephen Wakely <[email protected]> wrote: > This is a good pattern that will help in a lot of situations, but I don't > think it will catch everything. > > Unless I am missing something (very possible - I'm only just getting to > grips with this stuff) this relies on the parent and children knowing the > topic to pub/sub on. > > So for example say I have a list of a 1000 clients and each of these > clients has a sub component that let's you enter a new invoice to raise for > the client. When that invoice is entered the sub component needs to inform > the parent that it needs to update it's total. To push that info to the > correct client the sub component would need an ID value of the client that > needs updating. This ID would still need to be passed down the component > tree. If an ID is being passed down, you may as well just pass a channel > down instead. > > What would be awesome would be if you could specify some kind of > local-shared data that was only available to a component and all its > children. > > As a learning exercise I have been trying to hack something like this myself > into Om but so far have failed miserably. It has been an enlightening > experience though. > > > > -------- Original message -------- > From: David Nolen > Date:17/10/2014 4:28 PM (GMT+00:00) > To: [email protected] > Subject: Re: [ClojureScript] Om - Passing channels down through hierarchy > > This is not entirely true. core.async supports pub/sub on topics > making one global publish and one global notification channel a good > strategy. > > I recently wrote about this: > https://github.com/swannodette/om/wiki/Advanced-Tutorial > > David > > On Fri, Oct 17, 2014 at 11:11 AM, Stephen Wakely > <[email protected]> wrote: >> This would only work if there was only one global channel needed. >> >> It wouldn't work if you needed separate channels for different branches of >> the tree - say if you had multiple items in a list and each of those items >> needed a channel to pass to sub-components. >> >> On 17 October 2014 16:02, Jamie Orchard-Hays <[email protected]> wrote: >>> >>> I have a base component that creates a channel and then I pass the >>> channel >>> via the :opts key-value to its children. However, another user posted >>> recently that the :shared data could be modified as it is passed down the >>> hierarchy. It seems to me this would be a DRYer way to pass the channel >>> down >>> to descendants as you would not have to explicitly pass the channel in >>> :opts >>> at each descendant. >>> >>> Thoughts? >>> >>> Cheers, >>> >>> Jamie >>> >>> On Oct 16, 2014, at 11:21 PM, Brian Crescimanno >>> <[email protected]> wrote: >>> >>> > Hi everyone, >>> > >>> > I've been playing with Om the past few days both due to my own interest >>> > in Om itself as well as my long-standing desire to learn ClojureScript. >>> > With >>> > that in mind, I'm relatively new to both. >>> > >>> > After following the Om "Basic Tutorial" I set about creating my own >>> > demo >>> > app (a drag-and-drop rank-voting UI). One of the concepts I saw >>> > introduced >>> > in the tutorial was using Core.async channels to deal with events and I >>> > initially copied that paradigm into my app. Within a few minutes, I >>> > was >>> > realizing that I must be going down an anti-pattern path. >>> > >>> > One of the things I like best about Om so far is that it seems to >>> > encourage me to always be thinking about pieces of functionality as >>> > actual >>> > "components" rather than the traditional MVC paradigm. As I went along, >>> > I >>> > realized I was passing a channel down (via :init-state) through 4+ >>> > levels of >>> > component nesting. Any time I have to write the same block of code >>> > more >>> > than twice, I question it. >>> > >>> > After thinking on it a while, I assume it's probably better to pass the >>> > right cursor and modify the cursor directly from the interior >>> > components. >>> > In my case, my hierarchy looked like: >>> > >>> > items-view >>> > item-view >>> > item-detail >>> > vote-button >>> > >>> > ...with the bottom 3 all sharing the same cursor. >>> > >>> > That said, I wanted to ask around to folks using Om what the >>> > "idiomatic" >>> > approach is. I quickly started to think that the Basic Tutorial was >>> > likely >>> > introducing Core.async to help people get familiar with ClojureScript >>> > and >>> > not anticipating the anti-pattern it was establishing. But, since I >>> > don't >>> > know idiomatic approaches yet; I thought I would ask if there was >>> > something >>> > I'm missing in terms of using async channels more effectively. >>> > >>> > Thanks for the advice! >>> > >>> > Brian >>> > >>> > -- >>> > Note that posts from new members are moderated - please be patient with >>> > your first post. >>> > --- >>> > You received this message because you are subscribed to the Google >>> > Groups "ClojureScript" group. >>> > To unsubscribe from this group and stop receiving emails from it, send >>> > an email to [email protected]. >>> > To post to this group, send email to [email protected]. >>> > Visit this group at http://groups.google.com/group/clojurescript. >>> >>> -- >>> Note that posts from new members are moderated - please be patient with >>> your first post. >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "ClojureScript" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at http://groups.google.com/group/clojurescript. >> >> >> -- >> Note that posts from new members are moderated - please be patient with >> your >> first post. >> --- >> You received this message because you are subscribed to the Google Groups >> "ClojureScript" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/clojurescript. > > -- > Note that posts from new members are moderated - please be patient with your > first post. > --- > You received this message because you are subscribed to the Google Groups > "ClojureScript" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/clojurescript. > > -- > Note that posts from new members are moderated - please be patient with your > first post. > --- > You received this message because you are subscribed to the Google Groups > "ClojureScript" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/clojurescript. -- Note that posts from new members are moderated - please be patient with your first post. --- You received this message because you are subscribed to the Google Groups "ClojureScript" group. 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