I would argue if you have a matrix/cell pattern and you have to go several levels you have a design problem.
David On Fri, Oct 17, 2014 at 3:11 PM, Stephen Wakely <[email protected]> wrote: > Yes you can. But that does rely on passing the callbacks down the chain > which could be several layers deep. > > -------- Original message -------- > From: David Nolen > Date:17/10/2014 8:08 PM (GMT+00:00) > To: [email protected] > Subject: Re: [ClojureScript] Om - Passing channels down through hierarchy > > 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. > 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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