Slightly more robust (but still not robust) UI

RaftFable/src/App.fs

@@ -2,7 +2,6 @@ namespace RaftFable
 
 open System
 open System.Collections.Generic
-open System.Security.Cryptography
 open Fable.Core.JS
 open Raft
 open Browser.Dom
@@ -66,8 +65,8 @@ module App =
                     try
                         clients.Add (client, HashSet ())
                     with :? ArgumentException ->
-                        failwith "got a response a second time - need to handle this in the UI"
-                | RegisterClientResponse.NotLeader hint -> failwith "asked a non-leader, have to handle it"
+                        failwith "TODO: got a response a second time - need to handle this in the UI"
+                | RegisterClientResponse.NotLeader hint -> failwith "TODO: asked a non-leader, have to handle it"
             )
 
     let handleClientResponse (response : ClientResponse) : unit =
@@ -75,8 +74,8 @@ module App =
             clients
             (fun () ->
                 match response with
-                | ClientResponse.SessionExpired -> failwith "session expired, have to handle it"
-                | ClientResponse.NotLeader hint -> failwith "asked a non-leader, have to handle it"
+                | ClientResponse.SessionExpired -> failwith "TODO: session expired, have to handle it"
+                | ClientResponse.NotLeader hint -> failwith "TODO: asked a non-leader, have to handle it"
                 | ClientResponse.Success (client, sequence) ->
                     match clients.TryGetValue client with
                     | false, _ ->
@@ -140,15 +139,25 @@ module App =
     // TODO: what happens when we try and log client data on a node that doesn't know about the client?
 
     let reloadActions () =
-        // TODO: fix this button, it doesn't work properly
+        // TODO: fix this button, it doesn't work properly in the failure case
+        match Ui.getUserPrefs parseByte handleRegisterClientResponse handleClientResponse clusterSize ui with
+        | Error error ->
+            let error = sprintf "Unable to parse actions: %s" error
+            window.alert error
+            promise { return () }
+
+        | Ok newPrefs ->
+
         let newCluster, newNetwork = InMemoryCluster.make<byte> clusterSize
         cluster <- newCluster
         network <- newNetwork
 
-        userPrefs.Value <- Ui.getUserPrefs parseByte handleRegisterClientResponse handleClientResponse clusterSize ui
+        userPrefs.Value <-
+            { newPrefs with
+                ActionHistory = []
+            }
 
-        startupActions
-        |> fun s -> (fullyRerender parseByte userPrefs cluster network, s)
+        (promise { return () }, userPrefs.Value.ActionHistory)
         ||> List.fold (fun (inPromise : Promise<unit>) action ->
             promise {
                 let! _ = inPromise
@@ -218,7 +227,4 @@ module App =
             NetworkAction.ClientRequest (server, ClientRequest.RegisterClient handleRegisterClientResponse)
             |> perform parseByte userPrefs cluster network
 
-    ui.ShowConsumedMessages.onchange <-
-        fun _event ->
-            printfn "rerendering"
-            fullyRerender parseByte userPrefs cluster network
+    ui.ShowConsumedMessages.onchange <- fun _event -> fullyRerender parseByte userPrefs cluster network

RaftFable/src/Ui.fs

@@ -201,7 +201,7 @@ module Ui =
         let actionList =
             prefs.ActionHistory |> Seq.map NetworkAction.toString |> String.concat "\n"
 
-        ui.ActionHistoryList.textContent <- actionList
+        ui.ActionHistoryList.value <- actionList
 
     let render<'a>
         (perform : NetworkAction<'a> -> Fable.Core.JS.Promise<unit>)
@@ -399,25 +399,23 @@ module Ui =
         (handleClientDataResponse : ClientResponse -> unit)
         (clusterSize : int)
         (ui : UiElements)
-        : UserPreferences<'a>
+        : Result<UserPreferences<'a>, string>
         =
-        {
-            LeaderUnderConsideration = ui.SelectedLeaderId.valueAsNumber |> int |> (fun i -> i * 1<ServerId>)
-            ShowConsumedMessages = ui.ShowConsumedMessages.``checked``
-            ActionHistory =
-                // TODO write these back out again, and give a button to Load
-                ui.ActionHistoryList.textContent.Split "\n"
-                |> Seq.filter (not << System.String.IsNullOrEmpty)
-                |> Seq.map (
-                    NetworkAction.tryParse<'a>
-                        parse
-                        None
-                        handleRegisterClientResponse
-                        handleClientDataResponse
-                        clusterSize
-                )
-                |> Result.allOkOrError
-                // TODO handle this
-                |> Result.get
-                |> List.ofSeq
-        }
+        let actionHistory =
+            ui.ActionHistoryList.value.Split "\n"
+            |> Seq.filter (not << System.String.IsNullOrEmpty)
+            |> Seq.map (
+                NetworkAction.tryParse<'a> parse None handleRegisterClientResponse handleClientDataResponse clusterSize
+            )
+            |> Result.allOkOrError
+            |> Result.map List.ofSeq
+
+        match actionHistory with
+        | Result.Ok actionHistory ->
+            {
+                LeaderUnderConsideration = ui.SelectedLeaderId.valueAsNumber |> int |> (fun i -> i * 1<ServerId>)
+                ShowConsumedMessages = ui.ShowConsumedMessages.``checked``
+                ActionHistory = actionHistory
+            }
+            |> Result.Ok
+        | Result.Error e -> Result.Error (snd e |> String.concat "\n")