Merge pull request #21 from prjemian/issue_19

Issue 19: let user choose to write waveform strings as string or array of integers

src/pvWebMonitor/pvlist.xsd

@@ -6,7 +6,7 @@ XML Schema to validate the pvlist.xml file
 # See LICENSE file for details.
  -->
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
-
+  
   <xs:element name="pvwatch">
     <xs:complexType>
       <xs:sequence>
@@ -22,14 +22,15 @@ XML Schema to validate the pvlist.xml file
     <!-- used to tell humans what the terms mean in a pvlist.xml file -->
     <xs:attribute name="name" use="required" type="xs:NCName" />
   </xs:complexType>
-
+  
   <xs:complexType name="pv_type">
     <!-- defines the declaration of one PV to be monitored -->
     <xs:attribute name="PV" type="xs:NMTOKEN" use="required" />
     <xs:attribute name="description" type="xs:string" use="required" />
     <xs:attribute name="display_format" type="xs:string" use="optional" default="%s" />
     <xs:attribute name="mne" type="xs:NCName" use="required" />
     <xs:attribute name="_ignore_" type="xs:boolean" use="optional" default="false" />
+    <xs:attribute name="as_string" type="xs:boolean" use="optional" default="false" />
   </xs:complexType>
 
   <xs:attributeGroup name="version_type">
@@ -43,5 +44,5 @@ XML Schema to validate the pvlist.xml file
       </xs:simpleType>
     </xs:attribute>
   </xs:attributeGroup>
-
+  
 </xs:schema>

src/pvWebMonitor/pvwatch.py

@@ -126,30 +126,34 @@ def get_pvlist(self):
                 pv = key.get("PV")
                 desc = key.get("description")
                 fmt = key.get("display_format", "%s")  # default format
+                as_string = key.get("as_string", False)  # default format
+                # :see: http://cars9.uchicago.edu/software/python/pyepics3/pv.html?highlight=as_string#pv.get
                 try:
-                    self.add_pv(mne, pv, desc, fmt)
+                    self.add_pv(mne, pv, desc, fmt, as_string)
                 except:
                     msg = "%s: problem connecting: %s" % (pvlist_file, etree.tostring(key))
                     utils.logException(msg)
 
-    def add_pv(self, mne, pv, desc, fmt):
+    def add_pv(self, mne, pv, desc, fmt, as_string):
         '''Connect to a EPICS (PyEpics) process variable'''
         if pv in self.pvdb:
             msg = "key '%s' already defined by id=%s" % (pv, self.pvdb[pv]['id'])
             raise KeyError(msg)
 
         ch = epics.PV(pv)
         entry = {
-            'name': pv,           # EPICS PV name
-            'id': mne,            # symbolic name used in the python code
-            'description': desc,  # text description for humans
-            'timestamp': None,    # client time last monitor was received
-            'counter': 0,         # number of monitor events received
-            'units': "",          # engineering units
-            'ch': ch,             # EPICS PV channel
-            'format': fmt,        # format for display
-            'value': None,        # formatted value
-            'raw_value': None     # unformatted value
+            'name': pv,             # EPICS PV name
+            'id': mne,              # symbolic name used in the python code
+            'description': desc,    # text description for humans
+            'timestamp': None,      # client time last monitor was received
+            'counter': 0,           # number of monitor events received
+            'units': "",            # engineering units
+            'ch': ch,               # EPICS PV channel
+            'format': fmt,          # format for display
+            'value': None,          # formatted value
+            'raw_value': None,      # unformatted value
+            'char_value': None,     # string value
+            'as_string': as_string, # whether to return the string representation of the value
         }
         self.pvdb[pv] = entry
         self.xref[mne] = pv            # mne is local mnemonic, define actual PV in pvlist.xml
@@ -207,11 +211,15 @@ def update_pvdb(self, pv, raw_value):
             msg = '!!!ERROR!!! %s was not found in pvdb!' % pv
             raise PvNotRegistered, msg
         entry = self.pvdb[pv]
-        # ch = entry['ch']
+        ch = entry['ch']
         entry['timestamp'] = utils.getTime()
         entry['counter'] += 1
         entry['raw_value'] = raw_value
-        entry['value'] = entry['format'] % raw_value
+        entry['char_value'] = ch.char_value
+        if entry['as_string']:
+            entry['value'] = ch.char_value
+        else:
+            entry['value'] = entry['format'] % raw_value
 
     def EPICS_monitor_receiver(self, *args, **kws):
         '''Response to an EPICS (PyEpics) monitor on the channel'''
@@ -233,7 +241,7 @@ def buildReport(self):
 
         sorted_id_list = sorted(self.xref)
         fields = ("name", "id", "description", "timestamp", "record_type",
-                  "counter", "units", "value", "raw_value", "format")
+                  "counter", "units", "value", "char_value", "raw_value", "format")
 
         for mne in sorted_id_list:
             pv = self.xref[mne]