ENH: Archiver Timeplot address setters

pydm/widgets/archiver_time_plot.py

@@ -4,6 +4,7 @@
 from collections import OrderedDict
 from typing import List, Optional
 from pyqtgraph import DateAxisItem, ErrorBarItem
+from pydm.utilities import remove_protocol
 from pydm.widgets.channel import PyDMChannel
 from pydm.widgets.timeplot import TimePlotCurveItem
 from pydm.widgets import PyDMTimePlot
@@ -40,7 +41,7 @@ class ArchivePlotCurveItem(TimePlotCurveItem):
     archive_data_received_signal = Signal()
 
     def __init__(self, channel_address: Optional[str] = None, use_archive_data: bool = True, **kws):
-        super(ArchivePlotCurveItem, self).__init__(channel_address, **kws)
+        super(ArchivePlotCurveItem, self).__init__(**kws)
         self.use_archive_data = use_archive_data
         self.archive_channel = None
         self.archive_points_accumulated = 0
@@ -52,8 +53,7 @@ def __init__(self, channel_address: Optional[str] = None, use_archive_data: bool
         self.error_bar_item = ErrorBarItem()
         self.error_bar_needs_set = True
 
-        if channel_address is not None and use_archive_data:
-            self.setArchiveChannel(channel_address)
+        self.address = channel_address
 
     def to_dict(self) -> OrderedDict:
         """Returns an OrderedDict representation with values for all properties needed to recreate this curve."""
@@ -65,20 +65,32 @@ def to_dict(self) -> OrderedDict:
         dic_.update(super(ArchivePlotCurveItem, self).to_dict())
         return dic_
 
-    def setArchiveChannel(self, address: str) -> None:
+    @property
+    def address(self):
+        return super().address
+
+    @address.setter
+    def address(self, new_address: str) -> None:
         """Creates the channel for the input address for communicating with the archiver appliance plugin."""
-        archiver_prefix = "archiver://pv="
-        if address.startswith("ca://"):
-            archive_address = address.replace("ca://", archiver_prefix, 1)
-        elif address.startswith("pva://"):
-            archive_address = address.replace("pva://", archiver_prefix, 1)
-        else:
-            archive_address = archiver_prefix + address
+        TimePlotCurveItem.address.__set__(self, new_address)
 
+        if not new_address:
+            self.archive_channel = None
+            return
+        elif self.archive_channel and new_address == self.archive_channel.address:
+            return
+
+        # Prepare new address to use the archiver plugin and create the new channel
+        archive_address = "archiver://pv=" + remove_protocol(new_address)
         self.archive_channel = PyDMChannel(
             address=archive_address, value_slot=self.receiveArchiveData, value_signal=self.archive_data_request_signal
         )
 
+        # Clear the archive data of the previous channel and redraw the curve
+        if self.archive_points_accumulated:
+            self.initializeArchiveBuffer()
+            self.redrawCurve()
+
     @Slot(np.ndarray)
     def receiveArchiveData(self, data: np.ndarray) -> None:
         """Receive data from archiver appliance and place it into the archive data buffer.

pydm/widgets/timeplot.py

@@ -115,14 +115,23 @@ def address(self):
         return self.channel.address
 
     @address.setter
-    def address(self, new_address):
-        if new_address is None or len(str(new_address)) < 1:
+    def address(self, new_address: str):
+        """Creates the channel for the input address for communicating with the address' plugin."""
+        if not new_address:
             self.channel = None
             return
+        elif self.channel and new_address == self.channel.address:
+            return
+
         self.channel = PyDMChannel(
             address=new_address, connection_slot=self.connectionStateChanged, value_slot=self.receiveNewValue
         )
 
+        # Clear the data from the previous channel and redraw the curve
+        if self.points_accumulated:
+            self.initialize_buffer()
+            self.redrawCurve()
+
     @property
     def plotByTimeStamps(self):
         return self._plot_by_timestamps