+ # compute the 'accepts' part of a method, from a list of column names, and a fields dict
+ # use exclude=True to exclude the column names instead
+ # typically accepted_fields (Node.fields,['hostname','model',...])
+ @staticmethod
+ def accepted_fields (update_columns, fields_dict, exclude=False):
+ result={}
+ for (k,v) in fields_dict.iteritems():
+ if (not exclude and k in update_columns) or (exclude and k not in update_columns):
+ result[k]=v
+ return result
+
+ # filter out user-provided fields that are not part of the declared acceptance list
+ # keep it separate from split_fields for simplicity
+ # typically check_fields (<user_provided_dict>,{'hostname':Parameter(str,...),'model':Parameter(..)...})
+ @staticmethod
+ def check_fields (user_dict, accepted_fields):
+# avoid the simple, but silent, version
+# return dict ([ (k,v) for (k,v) in user_dict.items() if k in accepted_fields ])
+ result={}
+ for (k,v) in user_dict.items():
+ if k in accepted_fields: result[k]=v
+ else: raise PLCInvalidArgument ('Trying to set/change unaccepted key %s'%k)
+ return result
+