Regarding the outmsg and translating types, you've got 2 options - you can
either keep the outmsg in the scope of the module, or you can pass the
outmsg to the update function from the upper level:
*Outmsg in scope of module*
module MyModule exposing(..)
type Msg
= DoSomething
| DoSomethingElse
type OutMsg
= None
| SomethingHappened String
update : Msg -> Model -> ( Model, OutMsg, Cmd Msg )
update msg model =
case msg of
DoSomething ->
( model, None, Cmd.none )
DoSomethingElse ->
( model, SomethingHappened "I ate a block of cheese" , Cmd.none
)
*outmsg in the scope of parent via config*
module MyModule exposing(..)
type Msg
= DoSomething
| DoSomethingElse
type alias Config msg =
{ onSomethingHappened : String -> msg
, onNoOp : msg
}
update : Config msg -> Msg -> Model -> ( Model, msg , Cmd Msg )
update config msg model =
case msg of
DoSomething ->
( model, config.onNoOp , Cmd.none )
DoSomethingElse ->
( model, config.onSomethingHappened "I ate a block of cheese" ,
Cmd.none )
I'm using Nothing and NoOp in the respective examples - you might want to
use "Maybe" instead, and return Nothing or Just xxx .
How do I trigger a Cmd on the top-level from the update function of a
> module? Must be something to do with Cmd.map...?
Wherever you're managing the returned outmsg in the top level, generate the
Cmd from there.
On Tuesday, September 20, 2016 at 9:30:12 AM UTC-4, Rupert Smith wrote:
>
> On Sunday, September 18, 2016 at 9:33:14 PM UTC+1, Erik Lott wrote:
>>
>> I'm not sure what the outmessage package is that you linked to, but you
>> don't need a package to manage this. An outmsg is just a messge that is
>> returned from the update function, to notify the function caller of
>> something important that happened internally. If you're new to elm, it's
>> probably better to wire an OutMsg yourself, just so you know exactly what's
>> going on with the code. If you haven't yet seen the Sortable Table
>> Example <https://github.com/evancz/elm-sortable-table>, you should have
>> a close look at the code. You'll see great examples of the update and view
>> method returning useful messages.
>>
>
> Yes, I have struggled a bit to figure out how to do that, because I have
> split the code into module, and the return type of the 'update' function in
> a module is different to the return type of the 'update' function in the
> top-level module. How does one translate between those types?
>
> I can see how it is done for a view, using Html.App.map.
>
> How do I trigger a Cmd on the top-level from the update function of a
> module? Must be something to do with Cmd.map...?
>
>
--
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.
