Progressing with pickling. Pickling of PropModels doesn't work which cause

many classes that use it not to pickle.

SimPEG/Directives.py

@@ -8,6 +8,34 @@ class InversionDirective(object):
     def __init__(self, **kwargs):
         Utils.setKwargs(self, **kwargs)
 
+    # Pickleing support methods
+    def __getstate__(self):
+        '''
+        Method that makes the dictionary of the object pickleble, removes non-pickleble elements of the object.
+
+        Used when doing:
+            pickle.dump(pickleFile,object)
+        '''
+        odict = self.__dict__.copy()
+        # Remove fields that are not needed
+        del odict['hook']
+        del odict['setKwargs']
+        # Return the dict
+        return odict
+
+    def __setstate__(self,odict):
+        '''
+        Function that sets a pickle dictionary in to an object.
+
+        Used when doing:
+            object = pickle.load(pickleFile)
+        '''
+        # Update the dict
+        self.__dict__.update(odict)
+        # Re-hook the methods to the object
+        Utils.codeutils.hook(self,Utils.codeutils.hook)
+        Utils.codeutils.hook(self,Utils.codeutils.setKwargs)
+
     @property
     def inversion(self):
         """This is the inversion of the InversionDirective instance."""