Many thanks, Ambrose! That was very helpful indeed ; ) Gonna make it work.
On Mon, Sep 12, 2016 at 4:15 PM Ambrose Laing <[email protected]> wrote:
> Something like this can be made to work, if you don't care about relaxing
> the type safety which is provided by your current approach:
>
>
> initialModel =
> { form : Dict.fromList
> [ ("applicant",
>
> { label = "Applicant name"
> , selected = True
> , value = ""
>
> })
> , ("year",
>
> { label = "Year"
> , selected = True
> , value = ""
>
> })
> , ("state",
>
> { label = "State"
> , selected = True
> , value = ""
>
> })
> …
> ]
> …
> }
>
>
> type Msg
> = Update String String
>
>
>
> update msg model =
> case
> msg of
> Update fieldName query ->
> let
> entry =
> Dict.get fieldName model.form
>
> newEntry =
> { entry | value = query }
>
> form = Dict.insert fieldName newEntry model.form
> in
>
> ( { model | form = form }, Cmd.none )
>
>
> You should make it safer by including run-time checks that the first
> string argument (fieldName) is one of your 20 possibilities, before doing
> the above replacement, and if it isn't then you should specify what to do
> (maybe ignore it).
>
> On Monday, September 12, 2016 at 12:08:25 PM UTC-4, Eduardo Cuducos wrote:
>>
>> Hi all,
>>
>> I'm writing an application that has a “advanced search” form. In my
>> context it means a form with approx. 20 input fields.
>>
>> As a newbie the only way I could think of coding this is quite
>> repetitive. I bet that there is a more cleaver and a DRY way to do it, but
>> I couldn't figure out how. Any ideias?
>>
>> This is the terrible idea I have in mind:
>>
>> 1. My initial model would have 20 form fields definition like that:
>>
>> initialModel =
>> { form :
>> { applicant =
>> { label = "Applicant name"
>> , selected = True
>> , value = ""
>> , msg = UpdateApplicant
>> }
>> , year =
>> { label = "Year"
>> , selected = True
>> , value = ""
>> , msg = UpdateYear
>> }
>> , state =
>> { label = "State"
>> , selected = True
>> , value = ""
>> , msg = UpdateState
>> }
>> …
>> }
>> …
>> }
>>
>>
>> 2. Consequently my type Msg would have another 20 very similar fields:
>>
>> type Msg
>> = UpdateApplicant String
>> | UpdateYear String
>> | UpdateState
>> | …
>>
>> 3. And my update would have 20 very similar cases:
>>
>> update msg model =
>> case msg of
>> UpdateApplicant query ->
>> let
>> applicant =
>> model.form.applicant
>>
>> newApplicant =
>> { applicant | value = query }
>>
>> currentForm =
>> model.form
>>
>> form =
>> { currentForm | applicant = newApplicant }
>> in
>> ( { model | form = form }, Cmd.none )
>>
>> UpdateYear query ->
>> let
>> year =
>> model.form.year
>>
>> newYear =
>> { year | value = query }
>>
>> currentForm =
>> model.form
>>
>> form =
>> { currentForm | year = newYear }
>> in
>> ( { model | form = form }, Cmd.none )
>>
>> UpdateState query ->
>> let
>> state =
>> model.form.state
>>
>> newState =
>> { state | value = query }
>>
>> currentForm =
>> model.form
>>
>> form =
>> { currentForm | state = newState }
>> in
>> ( { model | form = form }, Cmd.none )
>>
>> Many thanks,
>>
>> --
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