Adds JSON decoding.

7 files changed, 86 insertions, 14 deletions

diff --git a/elm.json b/elm.json
index 7bb17ea..462aa2c 100644
--- a/elm.json
+++ b/elm.json
@@ -6,6 +6,7 @@
     "elm-version": "0.19.1",
     "dependencies": {
         "direct": {
+            "NoRedInk/elm-json-decode-pipeline": "1.0.1",
             "elm/browser": "1.0.1",
             "elm/core": "1.0.2",
             "elm/html": "1.0.0",
diff --git a/src/Comm/LoadStory.elm b/src/Comm/LoadStory.elm
new file mode 100644
index 0000000..869d21b
--- /dev/null
+++ b/src/Comm/LoadStory.elm
@@ -0,0 +1,34 @@
+module Comm.LoadStory exposing (request)
+
+-- Elm -------------------------------------------------------------------------
+import Http
+
+-- Tonkadur --------------------------------------------------------------------
+import Tonkadur.Json
+
+-- Local Module ----------------------------------------------------------------
+import Struct.Event
+
+--------------------------------------------------------------------------------
+-- TYPES -----------------------------------------------------------------------
+--------------------------------------------------------------------------------
+
+--------------------------------------------------------------------------------
+-- LOCAL -----------------------------------------------------------------------
+--------------------------------------------------------------------------------
+
+--------------------------------------------------------------------------------
+-- EXPORTED --------------------------------------------------------------------
+--------------------------------------------------------------------------------
+request : String -> (Cmd Struct.Event.Type)
+request story_url =
+   (Http.get
+      {
+         url = story_url,
+         expect =
+            (Http.expectJson
+               Struct.Event.LoadStory
+               (Tonkadur.Json.decoder)
+            )
+      }
+   )
diff --git a/src/ElmModule/Init.elm b/src/ElmModule/Init.elm
index 885153a..08c2540 100644
--- a/src/ElmModule/Init.elm
+++ b/src/ElmModule/Init.elm
@@ -5,6 +5,8 @@ import Struct.Flags
 import Struct.Event
 import Struct.Model
 
+import Comm.LoadStory
+
 --------------------------------------------------------------------------------
 -- LOCAL -----------------------------------------------------------------------
 --------------------------------------------------------------------------------
@@ -15,4 +17,4 @@ import Struct.Model
 init : Struct.Flags.Type -> (Struct.Model.Type, (Cmd Struct.Event.Type))
 init flags =
    -- TODO: read flags and request story.
-   ((Struct.Model.new), Cmd.none)
+   ((Struct.Model.new), (Comm.LoadStory.request "/story/0.json"))
diff --git a/src/ElmModule/Update.elm b/src/ElmModule/Update.elm
index 3dbad82..d7617bd 100644
--- a/src/ElmModule/Update.elm
+++ b/src/ElmModule/Update.elm
@@ -1,10 +1,12 @@
 module ElmModule.Update exposing (update)
 
 -- Elm -------------------------------------------------------------------------
+import Html
 
 -- Local Module ----------------------------------------------------------------
 import Struct.Event
 import Struct.Model
+import Struct.UI
 
 import Update.Story
 
@@ -22,6 +24,24 @@ update : (
    )
 update event model =
    case event of
-      Struct.Event.None -> (model, Cmd.none)
       (Struct.Event.ChoiceSelected ix) ->
          ((Update.Story.select_choice ix model), Cmd.none)
+
+      Struct.Event.None -> (model, Cmd.none)
+      (Struct.Event.LoadStory http_result) ->
+         case http_result of
+            (Ok story) ->
+               ((Update.Story.start {model | tonkadur = story}), Cmd.none)
+
+            (Err error) ->
+               (
+                  {model |
+                     ui =
+                        -- TODO: display the actual error.
+                        (Struct.UI.display_error
+                           (Html.text "Failed to load story")
+                           model.ui
+                        )
+                  },
+                  Cmd.none
+               )
diff --git a/src/Struct/Event.elm b/src/Struct/Event.elm
index 4493b1a..77fb564 100644
--- a/src/Struct/Event.elm
+++ b/src/Struct/Event.elm
@@ -1,6 +1,10 @@
 module Struct.Event exposing (..)
 
 -- Elm -------------------------------------------------------------------------
+import Http
+
+-- Tonkadur --------------------------------------------------------------------
+import Tonkadur.Types
 
 -- Local Module ----------------------------------------------------------------
 
@@ -10,6 +14,7 @@ module Struct.Event exposing (..)
 type Type =
    None
    | ChoiceSelected Int
+   | LoadStory (Result Http.Error Tonkadur.Types.State)
 
 --------------------------------------------------------------------------------
 -- LOCAL -----------------------------------------------------------------------
diff --git a/src/Tonkadur/Types.elm b/src/Tonkadur/Types.elm
index 929d848..bf8ae56 100644
--- a/src/Tonkadur/Types.elm
+++ b/src/Tonkadur/Types.elm
@@ -17,7 +17,6 @@ type alias TextData =
       effect_parameters : (List Value)
    }
 
-
 type RichText =
    StringText String
    | AugmentedText TextData
@@ -252,18 +251,26 @@ append_option option state =
 
 get_default : State -> String -> Value
 get_default state type_name =
-   case type_name of
-      "bool" -> (BoolValue False)
-      "float" -> (FloatValue 0.0)
-      "int" -> (IntValue 0)
-      "text" -> (TextValue (StringText ""))
-      "string" -> (StringValue "")
-      "list" -> (ListValue (Dict.empty))
-      "ptr" -> (PointerValue [])
-      other ->
-         case (Dict.get other state.user_types) of
+   case (maybe_get_default_primitive type_name) of
+      (Just value) -> value
+      Nothing ->
+         case (Dict.get type_name state.user_types) of
             (Just default) -> default
-            Nothing -> (StringValue ("Unknown type '" ++ other ++ "'"))
+            Nothing -> (StringValue ("Unknown type '" ++ type_name ++ "'"))
+
+-- Used during the decoding process, prior to 'state' being available, hence
+-- its separation from 'get_default'.
+maybe_get_default_primitive : String -> (Maybe Value)
+maybe_get_default_primitive type_name =
+   case type_name of
+      "bool" -> (Just (BoolValue False))
+      "float" -> (Just (FloatValue 0.0))
+      "int" -> (Just (IntValue 0))
+      "text" -> (Just (TextValue (StringText "")))
+      "string" -> (Just (StringValue ""))
+      "list" -> (Just (ListValue (Dict.empty)))
+      "ptr" -> (Just (PointerValue []))
+      _ -> Nothing
 
 apply_at_address : (
       (List String) ->
diff --git a/src/Update/Story.elm b/src/Update/Story.elm
index 4d1bfaa..68ed403 100644
--- a/src/Update/Story.elm
+++ b/src/Update/Story.elm
@@ -1,5 +1,6 @@
 module Update.Story exposing
    (
+      start,
       select_choice,
       input_string,
       input_integer,
@@ -135,6 +136,8 @@ step model =
 --------------------------------------------------------------------------------
 -- EXPORTED --------------------------------------------------------------------
 --------------------------------------------------------------------------------
+start : Struct.Model.Type -> Struct.Model.Type
+start model = (step model)
 
 select_choice : Int -> Struct.Model.Type -> Struct.Model.Type
 select_choice ix model = model