append file: check if the new file was already added

src/metadata_manager/MetadataManager.py

@@ -140,7 +140,6 @@ class MetadataManager (tango.LatestDeviceImpl):
         self.attr_lastDatafile_read = ''
         self.attr_dataFolder_read = ''
         self.attr_sampleParameters_read = ['']
-        self.attr_datafileList_read = ['']
         self.attr_datasetNameList_read = ['']
         #----- PROTECTED REGION ID(MetadataManager.init_device) ENABLED START -----#
         # init members
@@ -323,7 +322,7 @@ class MetadataManager (tango.LatestDeviceImpl):
         
     def write_lastDatafile(self, attr):
         data = attr.get_write_value()
-        if data and data != self.attr_lastDatafile_read:
+        if data and (not (data in self.attr_datafileList_read)):
             self.attr_datafileList_read.append(data)
         self.attr_lastDatafile_read = data