Ui improvements

- don't show custom fields in edit menu if there are none. This
reduces load of ui elements. The first custom field must be created in
manage-data page.

- Add more validation to the money type

modules/webapp/src/main/elm/Comp/CustomFieldInput.elm

@@ -13,6 +13,7 @@ import Api.Model.CustomField exposing (CustomField)
 import Api.Model.ItemFieldValue exposing (ItemFieldValue)
 import Comp.DatePicker
 import Data.CustomFieldType exposing (CustomFieldType)
+import Data.Money
 import Date exposing (Date)
 import DatePicker exposing (DatePicker)
 import Html exposing (..)
@@ -130,14 +131,14 @@ initWith value =
                 Data.CustomFieldType.Numeric ->
                     let
                         ( fm, _ ) =
-                            updateFloatModel value.value identity
+                            updateFloatModel value.value string2Float
                     in
                     NumberField fm
 
                 Data.CustomFieldType.Money ->
                     let
                         ( fm, _ ) =
-                            updateFloatModel value.value identity
+                            updateFloatModel value.value Data.Money.fromString
                     in
                     MoneyField fm
 
@@ -174,35 +175,32 @@ type alias UpdateResult =
     }
 
 
-updateFloatModel : String -> (Float -> Float) -> ( FloatModel, FieldResult )
-updateFloatModel msg rounding =
-    case String.toFloat msg of
-        Just n ->
-            let
-                fieldVal =
-                    if String.endsWith "." msg || String.endsWith ".0" msg then
-                        msg
-
-                    else
-                        String.fromFloat (rounding n)
-            in
-            ( { input = fieldVal
-              , result = Ok (rounding n)
+updateFloatModel : String -> (String -> Result String Float) -> ( FloatModel, FieldResult )
+updateFloatModel msg parse =
+    case parse msg of
+        Ok n ->
+            ( { input = msg
+              , result = Ok n
               }
-            , Value (String.fromFloat (rounding n))
+            , Value msg
             )
 
-        Nothing ->
+        Err err ->
             ( { input = msg
-              , result = Err ("Not a number: " ++ msg)
+              , result = Err err
               }
             , NoResult
             )
 
 
-roundScale2 : Float -> Float
-roundScale2 input =
-    (round (input * 100) |> toFloat) / 100
+string2Float : String -> Result String Float
+string2Float str =
+    case String.toFloat str of
+        Just n ->
+            Ok n
+
+        Nothing ->
+            Err ("Not a number: " ++ str)
 
 
 update : Msg -> Model -> UpdateResult
@@ -218,7 +216,7 @@ update msg model =
         ( NumberMsg str, NumberField _ ) ->
             let
                 ( fm, res ) =
-                    updateFloatModel str identity
+                    updateFloatModel str string2Float
 
                 model_ =
                     { model | fieldModel = NumberField fm }
@@ -228,7 +226,9 @@ update msg model =
         ( MoneyMsg str, MoneyField _ ) ->
             let
                 ( fm, res ) =
-                    updateFloatModel str roundScale2
+                    updateFloatModel
+                        str
+                        Data.Money.fromString
 
                 model_ =
                     { model | fieldModel = MoneyField fm }

modules/webapp/src/main/elm/Comp/CustomFieldMultiInput.elm

@@ -7,6 +7,7 @@ module Comp.CustomFieldMultiInput exposing
     , init
     , initCmd
     , initWith
+    , nonEmpty
     , setValues
     , update
     , view
@@ -59,6 +60,11 @@ type alias FieldSelect =
     }
 
 
+nonEmpty : Model -> Bool
+nonEmpty model =
+    not (List.isEmpty model.availableFields && List.isEmpty model.visibleFields)
+
+
 initWith : List CustomField -> Model
 initWith fields =
     { fieldModels = Dict.empty

modules/webapp/src/main/elm/Comp/ItemDetail/View.elm

@@ -729,6 +729,10 @@ renderEditForm settings model =
             else
                 span [ class "invisible hidden" ] []
 
+        showCustomFields =
+            fieldVisible Data.Fields.CustomFields
+                && Comp.CustomFieldMultiInput.nonEmpty model.customFieldsModel
+
         customFieldSettings =
             Comp.CustomFieldMultiInput.ViewSettings True "field"
     in
@@ -777,14 +781,20 @@ item visible. This message will disappear then.
                       """
                         ]
                     ]
-            , optional [ Data.Fields.CustomFields ] <|
+            , if showCustomFields then
                 h4 [ class "ui dividing header" ]
                     [ Icons.customFieldIcon ""
                     , text "Custom Fields"
                     ]
-            , optional [ Data.Fields.CustomFields ] <|
+
+              else
+                span [ class "hidden invisible" ] []
+            , if showCustomFields then
                 Html.map CustomFieldMsg
                     (Comp.CustomFieldMultiInput.view customFieldSettings model.customFieldsModel)
+
+              else
+                span [ class "hidden invisible" ] []
             , optional [ Data.Fields.DueDate, Data.Fields.Date ] <|
                 h4 [ class "ui dividing header" ]
                     [ Icons.itemDatesIcon ""

modules/webapp/src/main/elm/Data/Money.elm

@@ -0,0 +1,43 @@
+module Data.Money exposing
+    ( Money
+    , format
+    , fromString
+    , roundMoney
+    )
+
+
+type alias Money =
+    Float
+
+
+fromString : String -> Result String Money
+fromString str =
+    let
+        points =
+            String.indexes "." str
+
+        len =
+            String.length str
+    in
+    case points of
+        index :: [] ->
+            if index == (len - 3) then
+                String.toFloat str
+                    |> Maybe.map Ok
+                    |> Maybe.withDefault (Err "Two digits required after the dot.")
+
+            else
+                Err ("Two digits required after the dot: " ++ str)
+
+        _ ->
+            Err "One single dot + digits required for money."
+
+
+format : Float -> String
+format money =
+    String.fromFloat (roundMoney money)
+
+
+roundMoney : Float -> Float
+roundMoney input =
+    (round (input * 100) |> toFloat) / 100