Add lamassu-admin-elm to this repo (#185)

lamassu-admin-elm/src/FieldSet/Rest.elm

@@ -0,0 +1,95 @@
+module FieldSet.Rest exposing (..)
+
+import Json.Decode as D
+import Json.Encode as E
+import FieldSet.Types exposing (..)
+
+
+fieldPasswordDecoder : Bool -> FieldValue
+fieldPasswordDecoder present =
+    if present then
+        FieldPassword PasswordHidden
+    else
+        FieldPassword PasswordEmpty
+
+
+badInt : D.Decoder Int
+badInt =
+    D.oneOf [ D.int ]
+
+
+fieldValueDecoder : String -> D.Decoder FieldValue
+fieldValueDecoder fieldType =
+    case fieldType of
+        "string" ->
+            D.map FieldString D.string
+
+        "password" ->
+            D.map fieldPasswordDecoder D.bool
+
+        "integer" ->
+            D.map FieldInteger badInt
+
+        _ ->
+            D.fail ("Unsupported field type: " ++ fieldType)
+
+
+fieldDecoder : D.Decoder Field
+fieldDecoder =
+    (D.field "fieldType" D.string)
+        |> D.andThen
+            (\fieldType ->
+                D.map6 Field
+                    (D.field "code" D.string)
+                    (D.field "display" D.string)
+                    (D.oneOf [ D.field "placeholder" D.string, D.succeed "" ])
+                    (D.field "required" D.bool)
+                    (D.field "value" (fieldValueDecoder fieldType))
+                    (D.field "value" (fieldValueDecoder fieldType))
+            )
+
+
+encodeFieldValue : FieldValue -> E.Value
+encodeFieldValue fieldValue =
+    case fieldValue of
+        FieldString value ->
+            E.string value
+
+        FieldPassword value ->
+            case value of
+                Password s ->
+                    E.string s
+
+                _ ->
+                    E.null
+
+        FieldInteger value ->
+            E.int value
+
+
+maybeString : Maybe String -> E.Value
+maybeString maybeString =
+    case maybeString of
+        Nothing ->
+            E.null
+
+        Just s ->
+            E.string s
+
+
+encodeField : Field -> Maybe E.Value
+encodeField field =
+    if isDirty field then
+        Just
+            (E.object
+                [ ( "code", E.string field.code )
+                , ( "value", encodeFieldValue field.value )
+                ]
+            )
+    else
+        Nothing
+
+
+isDirty : Field -> Bool
+isDirty field =
+    field.value /= field.loadedValue