better handling for 'dead' messages from kernel

Author: maximsch2

TODO.md

@@ -1,6 +1,9 @@
+- Completion on file names and directories should work better
+- Better control for scrolling: if I have large ouput in the last cell that suddenly gets replaced, then my scroll position is screwed up
+	- Maybe shuold keep scroll position fixed while changing output!
+- Unclosed parenthesis still break highlighting (""" for python, and ' + " for R cells)
+- Initial scroll position is bad for empty notebooks
 - Support set_next_input
-- Correctly handle 'dead' message from the kernel
 - Add an option of saving a backup copy of notebook json file (use git to have all copies?):
     - For now it is possible to use inb_open_as_ipynb command
-- Completion on file names and directories should work better
 - Support image preview in some external program

ipy_connection.py

@@ -257,8 +257,7 @@ def __init__(self, notebook_id, baseurl):
         self.message_callbacks = dict()
         self.start_kernel()
         _thread.start_new_thread(self.process_messages, ())
-        self.status_callback = None
-        self.pager_callback = None
+        self.status_callback = lambda x: None
         self.encoding = 'utf-8'
 
     @property
@@ -280,11 +279,14 @@ def start_kernel(self):
         url = "http://" + self.baseurl + "/kernels?notebook=" + self.notebook_id
         req = urlopen(url, data=b"")  # data="" makes it POST request
         req.read()
+        self.create_websockets()
 
     def restart_kernel(self):
         url = "http://" + self.baseurl + "/kernels/" + self.kernel_id + "/restart"
         req = urlopen(url, data=b"")
         req.read()
+        self.create_websockets()
+        self.status_callback("idle")
 
     def interrupt_kernel(self):
         url = "http://" + self.baseurl + "/kernels/" + self.kernel_id + "/interrupt"
@@ -336,17 +338,17 @@ def register_callbacks(self, msg_id, output_callback,
     def process_messages(self):
         while True:
             m = self.message_queue.get()
-            try:
-                parent_id = m["parent_header"]["msg_id"]
-            except:
-                print(("No 'parent_header' in the message: " + str(m)))
-                continue
             content = m["content"]
             msg_type = m["header"]["msg_type"]
 
+            if ("parent_header" in m) and ("msg_id" in m["parent_header"]):
+                parent_id = m["parent_header"]["msg_id"]
+            else:
+                parent_id = None
+
             if msg_type == "status":
-                if self.status_callback:
-                    self.status_callback(content)
+                if "execution_state" in content:
+                    self.status_callback(content["execution_state"])
 
             elif parent_id in self.message_callbacks:
                 callbacks = self.message_callbacks[parent_id]
@@ -383,17 +385,25 @@ def grab_output(msg_type, content):
         return grab_output
 
     def create_websockets(self):
+        if self.shell is not None:
+            self.shell.close()
+
+        if self.iopub is not None:
+            self.iopub.close()
+
         url = "ws://" + self.baseurl + "/kernels/" + self.kernel_id + "/"
         self.shell = websocket.WebSocketApp(url=url + "shell",
                                             on_message=lambda ws, msg: self.on_shell_msg(msg),
-                                            on_open=lambda ws: ws.send("hallo_shell"))
+                                            on_open=lambda ws: ws.send(""),
+                                            on_error=lambda ws, err: print(err))
         self.iopub = websocket.WebSocketApp(url=url + "iopub",
                                             on_message=lambda ws, msg: self.on_iopub_msg(msg),
-                                            on_open=lambda ws: ws.send(""))
+                                            on_open=lambda ws: ws.send(""),
+                                            on_error=lambda ws, err: print(err))
 
         _thread.start_new_thread(self.shell.run_forever, ())
         _thread.start_new_thread(self.iopub.run_forever, ())
-        sleep(2)
+        sleep(1)
         self.running = True
 
     def create_message(self, msg_type, content):

ipy_view.py

@@ -216,7 +216,6 @@ def rewrite_prompt_number(self, edit):
     def output_result(self, edit):
         output = self.cell.output
         output = "\n".join(map(lambda s: " " + s, output.splitlines()))
-        print("output: '" + output + "'")
         self.write_to_region(edit, "inb_output", output)
 
     def draw(self, edit):
@@ -292,20 +291,20 @@ def __init__(self, view, notebook_id, baseurl):
         self.notebook_id = notebook_id
         self.kernel = create_kernel(baseurl, notebook_id)
         self.kernel.status_callback = self.on_status
-        self.on_status({"execution_state": "idle"})
+        self.on_status("idle")
         self.notebook = self.kernel.get_notebook()
         self.modified = False
         self.show_modified_status(False)
 
-        view.set_name("IPy Notebook - " + self.notebook.name)
+        self.set_name(self.notebook.name)
 
 
     def get_name(self):
         return self.notebook.name
 
     def set_name(self, new_name):
         self.notebook.name = new_name
-        view.set_name("IPy Notebook - " + self.notebook.name)
+        self.view.set_name("IPy Notebook - " + self.notebook.name)
 
     def get_cell_separator(self):
         return "\n\n"
@@ -472,10 +471,16 @@ def update_notebook_from_buffer(self):
         for cell in self.cells:
             cell.update_code()
 
-    def on_status(self, content):
+    def restart_kernel(self):
+        for cell in self.cells:
+            if isinstance(cell, CodeCellView):
+                cell.running = False
+        self.kernel.restart_kernel()
+
+
+    def on_status(self, execution_state):
         def set_status():
-            status = "kernel: " + content["execution_state"]
-            self.view.set_status("ExecutionStatus", status)
+            self.view.set_status("ExecutionStatus", "kernel: " + execution_state)
         sublime.set_timeout(set_status, 0)
 
     def handle_completions(self, view, prefix, locations):

subl_ipy_notebook.py

@@ -79,8 +79,8 @@ def run(self, edit, text):
 class InbRestartKernelCommand(sublime_plugin.TextCommand):
     def run(self, edit):
         nbview = manager.get_nb_view(self.view)
-        if nbview and nbview.kernel:
-            nbview.kernel.restart_kernel()
+        if nbview:
+            nbview.restart_kernel()
 
 
 class InbInterruptKernelCommand(sublime_plugin.TextCommand):