There was some discussion about this here
https://groups.google.com/forum/#!topic/clojurescript/_a5dPeElqG4 which
might help get you started.
What I do is basically something like this (untested so may need some work):
(defmixin listener
(will-unmount [owner]
(async/close! (om/get-state owner :listener-chan)))
(listen [owner callback]
(let [my-chan (async/chan)]
(go-loop []
(if-let [data (async/<! my-chan)]
(callback data)
(recur)))
(om/set-state! owner :listener-chan my-chan)
(async/tap global-mult my-chan))) ; note #1
and used like this:
(defcomponentk test-component []
(:mixins listener)
(will-mount [_]
(listen (fn [data] (println "Got data:" data))
...)
Then instead of calling om/build, you would do (->test-component data)
note #1:
global-mult is obtained using (async/mult sender-ch), where sender-ch is
the channel you put data on that you want to distribute to your components.
How sender-ch and global-mult is passed to your components is up to you
(you could use Om's shared state, for example).
Also, you don't have to use a mult if you don't want to multicast data to
all your listeners (or you could use many purpose-specific mults and pass
it into listen). In my real code I use pub/sub.
Hopefully this will give you some ideas to get you started.
On 30 October 2014 20:33, Colin Yates <[email protected]> wrote:
> I assumed so but thought I should check that there wasn't some fancy
> garbage collection thing happening.
>
> Do you happen to have a quick example of how to use the om-tools mixin
> to automatically unsubscribe?
>
> Thanks!
>
> On 30 October 2014 20:24, Daniel Kersten <[email protected]> wrote:
> > Yes, you should terminate the go block in will-unmont, otherwise if your
> > component is mounted multiple times, you will end up with multiple go
> blocks
> > consuming from the channel. If you are transacting on a cursor, then this
> > will just eat up resources, but if you are accessing owner (eg to get/set
> > local state) then you also risk accessing stale react components.
> >
> > I personally use an om-tools mixin to handle both subscribing and
> > unsubscribing to core.async pubs. This way I don't have to remember to
> > unsubscribe in unmount myself.
> >
> > On 30 October 2014 18:01, Colin Yates <[email protected]> wrote:
> >>
> >> (om/core.async newbie warning)
> >>
> >> I see a common pattern (including in the om tutorials) of using channels
> >> to communicate. Specifically I see code similar to:
> >>
> >> [code]
> >> om/IWillMount
> >> (will-mount [_]
> >> (let [nav (om/get-shared owner :nav-chan)]
> >> (go (loop []
> >> (let [page (<! nav)]
> >> (om/transact! app :page (fn [x] page))
> >> (recur))))
> >> [/code]
> >>
> >> What happens when that component is unmounted? Do I need to stop
> listening
> >> to that channel and if so how do I do that?
> >>
> >> I am not claiming there is a problem, I am simply asking if there is a
> >> potential problem and for clarity on the mechanics.
> >>
> >> For context, I am mounting/unmounting quite a bit as they navigate
> through
> >> the app.
> >>
> >> Thanks!
> >>
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