rework SECoP: redesign message class, fix command reply

seaweb.py

@@ -168,7 +168,7 @@ def reply():
         logging.error('%s', traceback.format_exc())
         circularlog.log()
         msg = dict(type='error', request=path[1:], error=repr(e))
-    resp = flask.Response(json.dumps(msg, cls=MyEncoder), mimetype='application/json')
+    resp = flask.Response(json.dumps(msg), mimetype='application/json')
     resp.headers['Access-Control-Allow-Origin'] = '*'
     return resp
 
@@ -860,22 +860,33 @@ class DummyInstrument(Instrument):
         return self.register(DummyClient(self.host_port))
 
 
-class SecopMsg:
-    par = None
-    value = None
+class SecopMsg(tuple):
+    asynch = False
 
-    def __init__(self, line):
-        sl = line.split(' ', 2)
+    def __new__(cls, line):
+        sl = (line+'  ').split(' ', 2)
         if len(sl[0].split(',')) > 1:
-            self.type = 'idn'
-            self.value = line
+            return tuple.__new__(cls, ('idn', None, line))
         else:
-            self.type = sl[0]
-            if len(sl) > 1:
-                self.par = sl[1]
-                if len(sl) > 2:
-                    self.value = json.loads(sl[2])
-        self.asynch = self.type in ('update', 'error_update')
+            typ, par, val = sl
+            val = val.strip() or None
+            if val:
+                val = json.loads(val)
+            if typ in ('update', 'error_update'):
+                cls = SecopAsyncMsg
+            return tuple.__new__(cls, (typ, par, val))
+
+    @property
+    def type(self):
+        return self[0]
+
+    @property
+    def par(self):
+        return self[1]
+
+    @property
+    def value(self):
+        return self[2]
 
     def __repr__(self):
         value = repr(self.value)
@@ -883,14 +894,9 @@ class SecopMsg:
             value = value[:50] + '...'
         return "SecopMsg('%s %s %s')" % (self.type, self.par, value)
 
-    def toJSON(self):
-        return json.dumps([self.type, self.par, self.value])
 
-
-class MyEncoder(json.JSONEncoder):
-    def default(self, obj):
-        toJSON = getattr(obj, 'toJSON')
-        return toJSON() if toJSON else super().default(obj)
+class SecopAsyncMsg(SecopMsg):
+    asynch = True
 
 
 def SecopEncode(cmd, par=None, value=None):
@@ -924,7 +930,7 @@ def convert_event(messages):
         if msg.type == 'update':
             updates.append(dict(name=msg.par, value=msg.value[0]))
         elif msg.type == 'error_update':
-            updates.append(dict(name=msg.par, value=f'{msg.value[0]} - {msg.value[1]}'))
+            updates.append(dict(name=msg.par, error=f'{msg.value[0]} - {msg.value[1]}'))
             # updates.append(dict(name=msg.par, value=str(msg.value[0])))
     return [dict(type='update', updates=updates)]
 
@@ -1074,8 +1080,8 @@ class SecopClient:
         else:
             replytype = None
          # cmd = "change " + command
-        print(command, replytype)
-        return node.cmd_reply(command, replytype)
+        reply = node.cmd_reply(command, replytype)
+        return dict(type='accept-command', result=reply)
 
     def poll(self):
         messages = []