ChangeSet.py

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#
# Copyright 2009, MeVis Medical Solutions AG
#
# The user may use this file in accordance with the license agreement provided with
# the Software or, alternatively, in accordance with the terms contained in a
# written agreement between the user and MeVis Medical Solutions AG.
#
# For further information use the contact form at https://www.mevislab.de/contact
#
 
 
 
# -- system imports ----------------------------------------------------------------------------{{{-
import os
import sys
import traceback
# ----------------------------------------------------------------------------------------------}}}-
 
# -- local imports -----------------------------------------------------------------------------{{{-
import mevis
# ----------------------------------------------------------------------------------------------}}}-
 
# -- class ChangeSet ---------------------------------------------------------------------------{{{-
 
class ChangeSet :
  # -- member variables ------------------------------------------------------------------------{{{-
  
  __changeDict = None
  
  __changeStack = None
  
  __ctx = None
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def __init__ ----------------------------------------------------------------------------{{{-
  
  def __init__ (self, context):
    self.__changeDict = {}
    self.__changeStack = []
    self.__ctx = context
    self.__enableAutoRevert = True
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def __del__ -----------------------------------------------------------------------------{{{-
  
  def __del__ (self):
    self.autoRevert()
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def _logInfo ----------------------------------------------------------------------------{{{-
  def _logInfo (self, message):
    mevis.MLAB.log(message)
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def _logError ---------------------------------------------------------------------------{{{-
  def _logError (self, message):
    mevis.MLAB.logError(message)
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def setFieldValue -----------------------------------------------------------------------{{{-
  
  def setFieldValue (self, fieldName, fieldValue, verbose=False):
    retVal = True
    field = self.__ctx.field(fieldName)
    if not field:
      if verbose:
        self._logError("Field (%s) not found in the used context!" % (fieldName))
      retVal = False
    else:
      fieldType = field.type
      if (fieldType in ('Trigger')) or fieldValue is None:
        if verbose:
          self._logInfo("Touched field %s" % (fieldName))
        field.touch()
      else:
        # Store old field value.
        oldFieldValue = getFieldValue(field)
        if fieldName not in self.__changeDict:
          self.__changeDict[fieldName] = oldFieldValue
          self.__changeStack.append(fieldName)
        self.__changeDict.setdefault(fieldName, oldFieldValue)
        setFieldValue(field, fieldValue)
        if verbose:
          self._logInfo("Set field %s to value %s" % (fieldName, fieldValue))
    return retVal
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def addField ----------------------------------------------------------------------------{{{-
  
  def addField (self, fieldName, verbose=False):
    field = self.__ctx.field(fieldName)
    if not field:
      if verbose:
        self._logError("Field (%s) not found in the used context!" % (fieldName))
      return False
    self.__changeDict.setdefault(fieldName, getFieldValue(field))
    return True
  # --------------------------------------------------------------------------------------------}}}-
 
  # -- def autoRevert --------------------------------------------------------------------------{{{-
  
  def autoRevert (self):
    if self.__enableAutoRevert and self.__ctx:      # the module might not exist anymore, so check
      self.revert()
  # --------------------------------------------------------------------------------------------}}}-
  
  # -- def revert ------------------------------------------------------------------------------{{{-
  
  def revert (self):
    # For each changed field restore the original value.
    while len(self.__changeStack) > 0:
      fieldName = self.__changeStack.pop(-1)
      field = self.__ctx.field(fieldName)
      setFieldValue(field, self.__changeDict[fieldName])
    self.__changeDict = {}
  # --------------------------------------------------------------------------------------------}}}-
  
  def enableAutoRevert (self, enable ):
    # Enable/disable revert on destruction. Can be disabled for debugging purposes (to leave the
    # network state as it was on error occurrence).
    self.__enableAutoRevert = enable
  # --------------------------------------------------------------------------------------------}}}-    
# ----------------------------------------------------------------------------------------------}}}-
 
def getFieldValue(field):
  if 'Vector6' in field.type:
    return field.stringValue()
  elif 'MLBase' in field.type:
    return field.object()
  else:
    return field.value
  
def setFieldValue(field, fieldValue):
  if 'Vector6' in field.type:
    if isinstance(fieldValue, (str, bytes)):
      field.setStringValue(fieldValue)
    else:
      field.setVectorValue(fieldValue)
  elif 'MLBase' in field.type:
    field.setObject(fieldValue)
  else:
    field.value = fieldValue