Re: [elm-discuss] Re: port module for JS interop.. without main/view ?
Just to clarify, inbound messages to Elm are batched (enqueued) and then
executed on nextTick.
And to echo Luke, observables would make more sense. A Promise-based
interface would mean supporting only request-response semantics.
Observables not only allow for request-response, but also publish-subscribe
semantics.
For example, suppose you have an Elm worker that processes stock tickers.
You send an inbound message to subscribe to one or more ticker symbols. An
outgoing port would continue to stream updates until you send a message to
unsubscribe from a particular ticker symbol (or all). I'm not sure how
you'd pull that off with Promises.
On Wednesday, July 27, 2016 at 9:44:27 PM UTC-4, Yonatan Kogan wrote:
>
> For us, we have multiple inbound ports and some outbound ports (inbound to
> elm from js, outbound to js from elm) so it's more useful.
>
> The send from Elm to JS is synchronous (newly in 0.17 I believe?) but
> going from JS to Elm is not, as it seems like Elm waits until nextTick to
> pick up the message (understandably). We still want to be able to say
> "after elm has processed this" though. The analogy would be "after this
> Ajax request has returned," so a Promise interface seems to make sense
> (again, I know nothing about Observables).
>
> I don't think this is stable, but it does seem like the following is
> effectively the same:
>
> ```js
> elmApp.ports.portName.send(message);
> setTimeout(function() {
> // use newly updated data
> });
> ```
>
> Also, writing that code highlights for me that our need is somewhat
> specific to elm updating a redux/flux store and we then want to take action
> on the updated store.
>
> On Wed, Jul 27, 2016 at 12:36 PM, Jörg Winter > wrote:
>
>> Just to clarify, I talk about calling Elm from JS.
>>
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>
>
>
> --
> Yonatan Kogan
>
>
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Re: [elm-discuss] Re: port module for JS interop.. without main/view ?
For us, we have multiple inbound ports and some outbound ports (inbound to
elm from js, outbound to js from elm) so it's more useful.
The send from Elm to JS is synchronous (newly in 0.17 I believe?) but going
from JS to Elm is not, as it seems like Elm waits until nextTick to pick up
the message (understandably). We still want to be able to say "after elm
has processed this" though. The analogy would be "after this Ajax request
has returned," so a Promise interface seems to make sense (again, I know
nothing about Observables).
I don't think this is stable, but it does seem like the following is
effectively the same:
```js
elmApp.ports.portName.send(message);
setTimeout(function() {
// use newly updated data
});
```
Also, writing that code highlights for me that our need is somewhat
specific to elm updating a redux/flux store and we then want to take action
on the updated store.
On Wed, Jul 27, 2016 at 12:36 PM, Jörg Winter wrote:
> Just to clarify, I talk about calling Elm from JS.
>
> --
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> "Elm Discuss" group.
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>
--
Yonatan Kogan
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Re: [elm-discuss] Re: port module for JS interop.. without main/view ?
Just to clarify, I talk about calling Elm from JS. -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [elm-discuss] Re: port module for JS interop.. without main/view ?
Do you think a correlating by Id is necessary ? If it is the simple case of having only 1 inbound and 1 outbound port in Elm and doing nothing async in Elm ... isn't a send/receive in JS basically synchronous ? A promise could still make sense but that Id would not be necessary. Some explanation in the Elm Guide would help a lot here. -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [elm-discuss] Re: port module for JS interop.. without main/view ?
We're doing this at work and I've strongly considered writing some promise
layer (disclaimer: I know nothing about observables). I was going to do
this by building a javascript module to manage the interface between JS and
elm that would assign every message into elm a unique ID (monotonically
increasing counter that's module-scoped in JS) and then have elm write out
it's response along with the unique id. The JS module moderating the
interface could then look up the promise it had returned by id and resolve
/ reject it as needed. I think this could be done pretty cleanly on the elm
side as well by enforcing that both input and output ports have a type
that's something like
```
type portMessage =
{ id : Int
, message: Json.Decode.Value
}
```
On Tue, Jul 26, 2016 at 2:34 PM, Jörg Winter wrote:
> Thanks!
>
> Guess you mean somehow combining (join, merge..) 2 Observables (sending +
> receiving to/from a port) to correlate the request(=send) with the
> reply(=subscribe-callback) ?
>
> --
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>
--
Yonatan Kogan
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[elm-discuss] Re: port module for JS interop.. without main/view ?
Thanks! Guess you mean somehow combining (join, merge..) 2 Observables (sending + receiving to/from a port) to correlate the request(=send) with the reply(=subscribe-callback) ? -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[elm-discuss] Re: port module for JS interop.. without main/view ?
ok.. admittedly going a bit offtopic here.. Did you actually mean Rx Subject ? otherwise, how would Observable help with correlating a port-send to a port-subscription event ? -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[elm-discuss] Re: port module for JS interop.. without main/view ?
Sure! Here's a gist containing such an example: https://gist.github.com/lukewestby/4983afbec4e0851db165d8298de05053 As far as wrapping things in a Promise, I think you would have better luck wrapping things up in an Observable. Ports going into and coming out of an Elm application are continuous, whereas we know Promises to be singular. It would take a bit of extra effort to be able to identify which call to `send` is responsible for which result from `subscribe`. It is possible, but using an Observable interface here might work better. -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[elm-discuss] Re: port module for JS interop.. without main/view ?
Great. That example shows only subscribing/receiving from Elm but not sending any input to Elm. Could you post an example showing send + subscribe ? Maybe such a Elm call (send with result) could be packaged a a JS promise too (?) -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[elm-discuss] Re: port module for JS interop.. without main/view ?
In the event that you want to use Elm.MyModule.worker() in the future, this module will let you set things up without worrying about the view part http://package.elm-lang.org/packages/lukewestby/worker/latest On Sunday, July 24, 2016 at 4:19:30 PM UTC-5, Jörg Winter wrote: > > Hey thanks for that blog-post about this use-case, exactly what I aimed > for initially. > > Meanwhile I discovered that the Elm.embed(node) interop-variant actually > makes sense for me so I can use Elm's view afterall. > Works great so far. > > -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[elm-discuss] Re: port module for JS interop.. without main/view ?
Hey thanks for that blog-post about this use-case, exactly what I aimed for initially. Meanwhile I discovered that the Elm.embed(node) interop-variant actually makes sense for me so I can use Elm's view afterall. Works great so far. -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[elm-discuss] Re: port module for JS interop.. without main/view ?
You do need a main, at the very least to pass init, update and subscriptions to the runtime that will iterate your app. View can return a single DOM node and be satisfied. It won't actually be displayed, but needs to be there. Elm works well in this scenario. Here's an example I did a while back: https://medium.com/@prozacchiwawa/the-im-stupid-elm-language-nugget-10-3a9c119ed6f9#.k0ywnnh2f On Saturday, July 23, 2016 at 3:20:26 PM UTC-7, Jörg Winter wrote: > > So I have this port module which lets me invoke elm-actions from JS and > get back results into JS > (Basically I just want to use this elm module like a library of elm > functions, no Html rendering needed!) > > It seems I have to give it a main function and use Html.App.program, which > in turn requires me to define a view function. > > Is there any way to expose ports to JS -without- defining a full blown > main + view ? > Just using Elm for implementing a library ? > > -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to elm-discuss+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
