Use elm/file to simplify file export

dist/index.html

@@ -32,24 +32,6 @@
       })
     });
 
-    /* Port for initiating download of graph export file */
-    app.ports.download.subscribe(function(msg) {
-      /* taken from https://stackoverflow.com/a/33542499/403702 */
-      var blob = new Blob([msg.data], {
-        type: 'text/plain'
-      });
-      if (window.navigator.msSaveOrOpenBlob) {
-        window.navigator.msSaveBlob(blob, msg.filename);
-      } else {
-        var elem = window.document.createElement('a');
-        elem.href = window.URL.createObjectURL(blob);
-        elem.download = msg.filename;
-        document.body.appendChild(elem);
-        elem.click();
-        document.body.removeChild(elem);
-      }
-    });
-
     /* Port for calling external graphviz library (viz.js). Given graphviz source
      * String (without layout info) it will generate output in graphviz "plain" format,
      * enriched by layout information (x,y) of individual nodes.

elm.json

@@ -8,6 +8,7 @@
         "direct": {
             "elm/browser": "1.0.1",
             "elm/core": "1.0.2",
+            "elm/file": "1.0.1",
             "elm/html": "1.0.0",
             "elm/json": "1.1.2",
             "elm/parser": "1.1.0",
@@ -18,6 +19,7 @@
         },
         "indirect": {
             "avh4/elm-fifo": "1.0.4",
+            "elm/bytes": "1.0.7",
             "elm/time": "1.0.0",
             "elm/url": "1.0.0",
             "elm/virtual-dom": "1.0.2"
@@ -31,4 +33,4 @@
             "elm/random": "1.0.0"
         }
     }
-}
+}

src/Main.elm

@@ -4,6 +4,7 @@ import Browser
 import Browser.Dom
 import Browser.Events
 import Export
+import File.Download
 import Graph exposing (NodeId)
 import GraphUtil
 import GraphViz.VizJs
@@ -229,19 +230,16 @@ update msg model =
 
         Download exportFormat ->
             let
-                ( fileExtension, graphToString ) =
+                ( graphToString, fileName ) =
                     case exportFormat of
                         Types.Dot ->
-                            ( "gv", Export.toDot )
+                            ( Export.toDot, "graph.dot" )
 
                         Types.Tgf ->
-                            ( "tgf", Export.toTgf )
+                            ( Export.toTgf, "graph.tgf" )
             in
             ( model
-            , Ports.download
-                { filename = "graph." ++ fileExtension
-                , data = graphToString model.graph
-                }
+            , File.Download.string fileName "text/plain" (graphToString model.graph)
             )
 
         ReceiveLayoutInfoFromGraphviz jsonVal ->

src/Ports.elm

@@ -1,6 +1,5 @@
 port module Ports exposing
-    ( download
-    , receiveGraphVizPlain
+    ( receiveGraphVizPlain
     , requestBoundingBoxesForContext
     , requestBoundingBoxesForEverything
     , requestEdgeTextBoundingBox
@@ -76,9 +75,6 @@ port requestBoundingBox : String -> Cmd msg
 port setBoundingBox : (BBox -> msg) -> Sub msg
 
 
-port download : { filename : String, data : String } -> Cmd msg
-
-
 {-| Request to transform Graphviz dot String to Graphviz plain.
 The resulting plain output will contain additional info about node layout which we'll parse out and adjust node positions for nicer layout.
 -}