feat: disable download and delete buttons if no sequences

src/apps/muscles/app.jl

@@ -51,6 +51,7 @@ const bonito_app = NamedApp(:inherit, Backbone.app)
     @out new_clipboard_item = false
 
     @in delete_sequence_click = false
+    @out no_sequences_yet = true
 
     @onchange isready begin
         _, url = init_model(__model__)
@@ -151,6 +152,8 @@ const bonito_app = NamedApp(:inherit, Backbone.app)
         notify(start_time)
         notify(time_interval)
         notify(series_length)
+        # enable the download and delete buttons
+        no_sequences_yet = false
         # toggle edit mode on
         editmode = true
     end
@@ -280,6 +283,8 @@ const bonito_app = NamedApp(:inherit, Backbone.app)
             end
             # reset
             fileuploads = empty!(fileuploads)
+            # enable the download and delete buttons
+            no_sequences_yet = false
         end
     end
 
@@ -309,6 +314,8 @@ const bonito_app = NamedApp(:inherit, Backbone.app)
             selected_sequence_name = ""
             # update the view
             sequence_name = ""
+            # disable the download and delete buttons (view)
+            no_sequences_yet = true
             # update the model
             model.sequence[] = sequence
         else
@@ -338,7 +345,7 @@ function muscle_view(bonito_url=""; channel=":channel")
                       label="Upload motor program(s)", autoupload=true, hideuploadbtn=true,
                       class="no-file-listing", id="uploader", url="/____/upload/$channel")),
         item(btn("Download motor program", @click(:export_sequence_click), color="primary",
-                 loading=:export_sequence_click,
+                 loading=:export_sequence_click, disable=:no_sequences_yet,
                  [tooltip("Download the current motor program as a JSON file")])),
         dropdown(:selected_sequence_name, :sequence_names, "Motor program",
                  class="sequence-list"),
@@ -362,7 +369,8 @@ function muscle_view(bonito_url=""; channel=":channel")
             textfield("Start time", :start_time, type="number", step="any",
                       disable=:editmode_disable),
         ]),
-        item(btn("Delete motor program", @click(:delete_sequence_click), color="negative")),
+        item(btn("Delete motor program", @click(:delete_sequence_click), color="negative",
+                 disable=:no_sequences_yet)),
     ])
 
     Html.div(style=col, [