🦋 Fix disconnect on cell deletion

Project.toml

@@ -2,7 +2,7 @@ name = "Pluto"
 uuid = "c3e4b0f8-55cb-11ea-2926-15256bba5781"
 license = "MIT"
 authors = ["Fons van der Plas <[email protected]>", "Mikołaj Bochenski <[email protected]>"]
-version = "0.5.2"
+version = "0.5.3"
 
 [deps]
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"

assets/editor.js

@@ -294,6 +294,9 @@ document.addEventListener("DOMContentLoaded", () => {
     }
 
     function requestRunAllRemoteCells() {
+        for (var uuid in window.localCells) {
+            window.localCells[uuid].classList.add("running")
+        }
         client.send("runall", {})
     }
 

src/notebookserver/Client.jl

@@ -1,11 +1,16 @@
 mutable struct Client
     id::Symbol
     stream::Any
+    stream_accesstoken::Channel{Nothing}
     connected_notebook::Union{Notebook,Nothing}
     pendingupdates::Channel
 end
 
-Client(id::Symbol, stream) = Client(id, stream, nothing, Channel(128))
+Client(id::Symbol, stream) = let
+    at = Channel{Nothing}(1)
+    put!(at, nothing)
+    Client(id, stream, at, nothing, Channel(128))
+end
 
 
 struct UpdateMessage

src/react/Run.jl

@@ -65,7 +65,7 @@ end
 
 
 "See `run_reactive`."
-function run_reactive_async!(initiator, notebook::Notebook, cells::Array{Cell, 1})
+function run_reactive_async!(initiator, notebook::Notebook, cells::Array{Cell, 1})::Task
 	@async begin
 		# because this is being run async, we need to catch exceptions manually
 		try

src/webserver/Dynamic.jl

@@ -107,7 +107,7 @@ function clientupdate_notebook_list(initiator::Client, notebook_list)
 end
 
 
-function handle_changecell(initiator::Client, notebook, cell, newcode)
+function handle_changecell(initiator::Client, notebook, cell, newcode)::Task
     # i.e. Ctrl+Enter was pressed on this cell
     # we update our `Notebook` and start execution
 
@@ -136,18 +136,22 @@ responses[:addcell] = (initiator::Client, body, notebook::Notebook) -> begin
     insert!(notebook.cells, new_index, new_cell)
 
     putnotebookupdates!(notebook, clientupdate_cell_added(initiator, notebook, new_cell, new_index))
-    nothing
 end
 
 responses[:deletecell] = (initiator::Client, body, notebook::Notebook, cell::Cell) -> begin
     to_delete = cell
 
-    changecell_succes = handle_changecell(initiator, notebook, to_delete, "")
+    # replace the cell's code with "" and do a reactive run
+    runtask = handle_changecell(initiator, notebook, to_delete, "")
 
-    filter!(c->c.uuid ≠ to_delete.uuid, notebook.cells)
-
-    putnotebookupdates!(notebook, clientupdate_cell_deleted(initiator, notebook, to_delete))
-    nothing
+    # wait for the reactive run to finish, then delete the cells
+    # we wait async, to make sure that the web server remains responsive
+    @async begin
+        wait(runtask)
+
+        filter!(c->c.uuid ≠ to_delete.uuid, notebook.cells)
+        putnotebookupdates!(notebook, clientupdate_cell_deleted(initiator, notebook, to_delete))
+    end
 end
 
 responses[:movecell] = (initiator::Client, body, notebook::Notebook, cell::Cell) -> begin
@@ -170,14 +174,12 @@ responses[:movecell] = (initiator::Client, body, notebook::Notebook, cell::Cell)
     end
 
     putnotebookupdates!(notebook, clientupdate_cell_moved(initiator, notebook, to_move, new_index))
-    nothing
 end
 
 responses[:changecell] = (initiator::Client, body, notebook::Notebook, cell::Cell) -> begin
     newcode = body["code"]
 
     handle_changecell(initiator, notebook, cell, newcode)
-    nothing
 end
 
 responses[:runall] = (initiator::Client, body, notebook::Notebook) -> begin
@@ -200,10 +202,8 @@ responses[:getallcells] = (initiator::Client, body, notebook::Notebook) -> begin
     # [clientupdate_cell_added(notebook, c, i) for (i, c) in enumerate(notebook.cells)]
 
     putnotebookupdates!(notebook, updates...)
-    nothing
 end
 
 responses[:getallnotebooks] = (initiator::Client, body, notebook=nothing) -> begin
     putplutoupdates!(clientupdate_notebook_list(initiator, values(notebooks)))
-    nothing
 end

src/webserver/WebServer.jl

@@ -48,6 +48,7 @@ function flushclient(client)
         next_to_send = take!(client.pendingupdates)
         didsomething = true
 
+        token = take!(client.stream_accesstoken)
         try
             if client.stream !== nothing
                 if isopen(client.stream)
@@ -62,6 +63,7 @@ function flushclient(client)
             @warn "Failed to write to WebSocket of $(client.id) " exception=(ex,bt)
             return false
         end
+        put!(client.stream_accesstoken, token)
     end
     # put!(flushtoken, nothing)
     true