Merge pull request #984 from YektaY/pva_nttable

ENH: PyDMNTTable Widget

Author: jbellister-slac

docs/source/data_plugins/p4p_plugin.rst

@@ -28,7 +28,7 @@ P4P is the only option (and will be chosen automatically if this variable is not
 in the future.
 
 Supported Types
----------------
+===============
 
 Currently this data plugin supports all `normative types`_. The values and control variables are pulled out of
 the data received and sent through the existing PyDM signals to be read by widgets via the channels they are
@@ -39,6 +39,29 @@ currently possible in this version of the plugin. For example, defining a group
 result in the named fields being sent to the widgets. Full support for structured data is planned to be supported
 as part of a future release.
 
+NTTables
+--------
+
+The plugin accepts NTTables. It will convert NTTables in python dictionaries which are then passed to the pydm widgets. 
+Not all widgets will accept a dictionary (or the whole NTTable) as an input. 
+A specified section of the NTTable can be passed to a those pydm widgets which do not accept dictionaries.
+If the PV is passing an NTTable and the user wants to pass only a specific subfield of the NTTable this can be achieved via appending a ``/`` 
+followed by the key or name of the column header of the subfield of the NTTable.
+For example::
+
+    pva://MTEST/subfield
+
+multiple layers of subfields also works::
+
+    pva://MTEST/sub-field/subfield_of_a_subfield
+
+Note: currenty subfields can only be used to read a subset of data from an NTTables 
+and can't be used to write to the subfield. A follow up release will add an ability to 
+write to the subfield.    
+
+Image decompression
+-------------------
+
 Image decompression is performed when image data is specified using an ``NTNDArray`` with the ``codec`` field set.
 The decompression algorithm to apply will be determined by what the ``codec`` field is set to. In order
 for decompression to happen, the python package for the associated codec must be installed in the environment

docs/source/widgets/nt_table.rst

@@ -0,0 +1,13 @@
+#######################
+PyDMNTTable
+#######################
+
+.. autoclass:: pydm.widgets.nt_table.PythonTableModel
+   :members:
+   :inherited-members:
+   :show-inheritance:
+
+.. autoclass:: pydm.widgets.nt_table.PyDMNTTable
+   :members:
+   :inherited-members:
+   :show-inheritance:

pydm/data_plugins/__init__.py

@@ -14,8 +14,7 @@
 from qtpy.QtWidgets import QApplication
 
 from .. import config
-from ..utilities import (import_module_by_filename, log_failures,
-                         protocol_and_address)
+from ..utilities import (import_module_by_filename, log_failures, parsed_address)
 from .plugin import PyDMPlugin
 
 logger = logging.getLogger(__name__)
@@ -77,15 +76,20 @@ def plugin_for_address(address: str) -> Optional[PyDMPlugin]:
     Find the correct PyDMPlugin for a channel
     """
     # Check for a configured protocol
-    protocol, addr = protocol_and_address(address)
+    try:
+        protocol = parsed_address(address).scheme
+    except AttributeError:
+        protocol = None 
+    
     # Use default protocol
     if protocol is None and config.DEFAULT_PROTOCOL is not None:
         logger.debug("Using default protocol %s for %s",
                      config.DEFAULT_PROTOCOL, address)
         # If no protocol was specified, and the default protocol
         # environment variable is specified, try to use that instead.
         protocol = config.DEFAULT_PROTOCOL
-    # Load proper plugin module
+
+    # Load proper plugin module    
     if protocol:
         initialize_plugins_if_needed()
         try:
@@ -98,6 +102,7 @@ def plugin_for_address(address: str) -> Optional[PyDMPlugin]:
                  "will receive no data. To specify a default protocol, "
                  "set the PYDM_DEFAULT_PROTOCOL environment variable."
                  "".format(addr=address))
+    
     return None
 
 

pydm/data_plugins/epics_plugins/p4p_plugin_component.py

@@ -1,6 +1,6 @@
 import logging
 import numpy as np
-
+import collections
 from p4p.client.thread import Context, Disconnected
 from p4p.wrapper import Value
 from .pva_codec import decompress
@@ -19,7 +19,6 @@ def __init__(self, channel: PyDMChannel, address: str,
                  protocol: Optional[str] = None, parent: Optional[QObject] = None):
         """
         Manages the connection to a channel using the P4P library. A given channel can have multiple listeners.
-
         Parameters
         ----------
         channel : PyDMChannel
@@ -33,7 +32,7 @@ def __init__(self, channel: PyDMChannel, address: str,
         """
         super().__init__(channel, address, protocol, parent)
         self._connected = False
-        self.monitor = P4PPlugin.context.monitor(name=address,
+        self.monitor = P4PPlugin.context.monitor(name=self.address,
                                                  cb=self.send_new_value,
                                                  notify_disconnect=True)
         self.add_listener(channel)
@@ -49,6 +48,7 @@ def __init__(self, channel: PyDMChannel, address: str,
         self._upper_warning_limit = None
         self._lower_warning_limit = None
         self._timestamp = None
+        self.nttable_data_location = PyDMPlugin.get_subfield(channel)
 
     def clear_cache(self) -> None:
         """ Clear out all the stored values of this connection. """
@@ -65,6 +65,8 @@ def clear_cache(self) -> None:
         self._lower_warning_limit = None
         self._timestamp = None
 
+        self.nttable_data_location = None 
+
     def send_new_value(self, value: Value) -> None:
         """ Callback invoked whenever a new value is received by our monitor. Emits signals based on values changed. """
         if isinstance(value, Disconnected):
@@ -79,9 +81,45 @@ def send_new_value(self, value: Value) -> None:
                 self.write_access_signal.emit(True)
 
             self._value = value
+            has_value_changed_yet = False
             for changed_value in value.changedSet():
-                if changed_value == 'value':
-                    new_value = value.value
+                if changed_value == 'value' or changed_value.split('.')[0] == 'value':
+                    # NTTable has a changedSet item for each column that has changed
+                    # Since we want to send an update on any table change, let's track
+                    # if the value item has been updated yet
+                    if has_value_changed_yet:
+                        continue
+                    else:
+                        has_value_changed_yet = True
+                    
+                    if 'NTTable' in value.getID():
+                        new_value = value.value.todict()
+                    else:
+                        new_value = value.value
+                    
+                    if self.nttable_data_location:
+                        msg = f"Invalid channel... {self.nttable_data_location}"
+
+                        for value in self.nttable_data_location:
+                            if isinstance(new_value, collections.Container) and not isinstance(new_value, str):
+                                
+                                if type(value) == str:
+                                    try:
+                                        new_value = new_value[value] 
+                                        continue
+                                    except TypeError:
+                                        logger.debug('Type Error when attempting to use the given key, code will next attempt to convert the key to an int')
+                                    except KeyError:
+                                        logger.exception(msg)
+                                    
+                                    try:
+                                        new_value = new_value[int(value)] 
+                                    except ValueError:
+                                        logger.exception(msg, exc_info=True)
+                            else:
+                                logger.exception(msg, exc_info=True)
+                                raise ValueError(msg)
+
                     if new_value is not None:
                         if isinstance(new_value, np.ndarray):
                             if 'NTNDArray' in value.getID():
@@ -95,6 +133,8 @@ def send_new_value(self, value: Value) -> None:
                             self.new_value_signal[int].emit(new_value)
                         elif isinstance(new_value, str):
                             self.new_value_signal[str].emit(new_value)
+                        elif isinstance(new_value, dict):
+                            self.new_value_signal[dict].emit(new_value)
                         else:
                             raise ValueError(f'No matching signal for value: {new_value} with type: {type(new_value)}')
                 # Sometimes unchanged control variables appear to be returned with value changes, so checking against
@@ -149,7 +189,6 @@ def put_value(self, value):
     def add_listener(self, channel: PyDMChannel):
         """
         Adds a listener to this connection, connecting the appropriate signals/slots to the input PyDMChannel.
-
         Parameters
         ----------
         channel : PyDMChannel
@@ -183,6 +222,10 @@ def add_listener(self, channel: PyDMChannel):
                 channel.value_signal[np.ndarray].connect(self.put_value, Qt.QueuedConnection)
             except KeyError:
                 pass
+            try:
+                channel.value_signal[dict].connect(self.put_value, Qt.QueuedConnection)
+            except KeyError:
+                pass
 
     def close(self):
         """ Closes out this connection. """

pydm/data_plugins/plugin.py

@@ -5,14 +5,14 @@
 from numpy import ndarray
 from typing import Optional, Callable
 
-from ..utilities.remove_protocol import protocol_and_address
+from ..utilities.remove_protocol import parsed_address
 from qtpy.QtCore import Signal, QObject, Qt
 from qtpy.QtWidgets import QApplication
 from .. import config
-
+import re
 
 class PyDMConnection(QObject):
-    new_value_signal = Signal([float], [int], [str], [ndarray], [bool])
+    new_value_signal = Signal([float], [int], [str], [bool], [object])
     connection_state_signal = Signal(bool)
     new_severity_signal = Signal(int)
     write_access_signal = Signal(bool)
@@ -55,14 +55,14 @@ def add_listener(self, channel):
             except TypeError:
                 pass
             try:
-                self.new_value_signal[ndarray].connect(channel.value_slot, Qt.QueuedConnection)
+                self.new_value_signal[bool].connect(channel.value_slot, Qt.QueuedConnection)
             except TypeError:
                 pass
             try:
-                self.new_value_signal[bool].connect(channel.value_slot, Qt.QueuedConnection)
+                self.new_value_signal[object].connect(channel.value_slot, Qt.QueuedConnection)
             except TypeError:
                 pass
-
+        
         if channel.severity_slot is not None:
             self.new_severity_signal.connect(channel.severity_slot, Qt.QueuedConnection)
 
@@ -134,14 +134,14 @@ def remove_listener(self, channel, destroying: Optional[bool] = False) -> None:
             except TypeError:
                 pass
             try:
-                self.new_value_signal[ndarray].disconnect(channel.value_slot)
+                self.new_value_signal[bool].disconnect(channel.value_slot)
             except TypeError:
                 pass
             try:
-                self.new_value_signal[bool].disconnect(channel.value_slot)
+                self.new_value_signal[object].disconnect(channel.value_slot)
             except TypeError:
                 pass
-
+        
         if self._should_disconnect(channel.severity_slot, destroying):
             try:
                 self.new_severity_signal.disconnect(channel.severity_slot)
@@ -250,19 +250,52 @@ def __init__(self):
         self.channels = weakref.WeakSet()
         self.lock = threading.Lock()
 
+    @staticmethod
+    def get_full_address(channel):
+        parsed_addr = parsed_address(channel.address)
+
+        if parsed_addr:
+            full_addr = parsed_addr.netloc + parsed_addr.path
+        else: 
+            full_addr = None
+
+        return full_addr
+
     @staticmethod
     def get_address(channel):
-        return protocol_and_address(channel.address)[1]
+        parsed_addr = parsed_address(channel.address)
+        addr = parsed_addr.netloc
+        protocol = parsed_addr.scheme
+
+        if protocol == 'calc' or protocol == 'loc':
+            addr = parsed_addr.netloc + '?' + parsed_addr.query
+        
+        return addr
+    
+    @staticmethod
+    def get_subfield(channel):
+        parsed_addr = parsed_address(channel.address)
+
+        if parsed_addr:
+            subfield = parsed_addr.path
+
+            if subfield != '':
+                subfield = subfield[1:].split('/')
+        else:
+            subfield = None
+        
+        return subfield
 
     @staticmethod
     def get_connection_id(channel):
-        return PyDMPlugin.get_address(channel)
+        return PyDMPlugin.get_full_address(channel)
 
     def add_connection(self, channel):
         from pydm.utilities import is_qt_designer
         with self.lock:
             connection_id = self.get_connection_id(channel)
             address = self.get_address(channel)
+
             # If this channel is already connected to this plugin lets ignore
             if channel in self.channels:
                 return

pydm/tests/test_data_plugins_import.py

@@ -39,13 +39,13 @@ def test_plugin_directory_loading(qapp, caplog):
         os.remove(os.path.join(cur_dir, 'plugin_foo.py'))
 
 
-def test_plugin_for_address(test_plugin):
+def test_plugin_for_address(test_plugin, monkeypatch):
     # Get by protocol
     assert isinstance(plugin_for_address('tst://tst:this'),
                       test_plugin)
     assert plugin_for_address('tst:this') is None
     # Default protocol
-    config.DEFAULT_PROTOCOL = 'tst'
+    monkeypatch.setattr(config, 'DEFAULT_PROTOCOL', 'tst')
     assert isinstance(plugin_for_address('tst:this'),
                       test_plugin)
 

pydm/tests/utilities/test_remove_protocol.py

@@ -1,5 +1,6 @@
 from ...utilities.remove_protocol import remove_protocol
-
+from ...utilities.remove_protocol import protocol_and_address
+from ...utilities.remove_protocol import parsed_address
 
 def test_remove_protocol():
     out = remove_protocol('foo://bar')
@@ -10,3 +11,22 @@ def test_remove_protocol():
 
     out = remove_protocol('foo://bar://foo2')
     assert (out == 'bar://foo2')
+
+def test_protocol_and_address():
+    out = protocol_and_address('foo://bar')
+    assert (out == ('foo', 'bar'))
+
+    out = protocol_and_address('foo:/bar')
+    assert (out == (None, 'foo:/bar'))
+
+def test_parsed_address():
+    out = parsed_address(1)
+    assert (out == None)
+
+    out = parsed_address('foo:/bar')
+    assert (out == None)
+
+    out = parsed_address('foo://bar')
+    assert (out == ('foo', 'bar', '', '', '', ''))
+
+

pydm/utilities/__init__.py

@@ -17,7 +17,7 @@
 from . import colors, macro, shortcuts
 from .connection import close_widget_connections, establish_widget_connections
 from .iconfont import IconFont
-from .remove_protocol import protocol_and_address, remove_protocol
+from .remove_protocol import protocol_and_address, remove_protocol, parsed_address
 from .units import convert, find_unit_options, find_unittype
 
 logger = logging.getLogger(__name__)