I just ran across what I consider a significant deficiency in Flex. To correct this problem would require an addition of two attributes to the mx:DataGridColumn class.
I could make a change to my version of the language, or perhaps I could create an inherited class. However, I feel strongly that the problem is so fundamental that it should be changed in the language. How do I go about making this happen? The problem is this; It appears that when sorting a DataGrid by clicking a column that Flex currently does its best to determine the data type and sorts based on that data type. The problem is that it gets confused when there are nulls in date, numeric, or boolean fields. When it gets confused it ralph's on its shoes (blows up). Based on my research, including reading a bit of the file sortField.as, this is by design. There is a way around it but it requires instantiating a compare function for each column that might get a null, and might be one of non string data types. The workaround is to create a function, and use the "sortCompareFunction" attribute to call a that function. There is even a kludgier workaround to make the function generic by using the "headerRelease" attribute of the DataGrid to update a public variable with the column number. Since it seems as though this is an ubiquitous problem, it should be solved in the language itself. The best approach that I came up with is to have two new attributes for the mx:DataGridColumn; sortDataType - Basically specify the type of data contained in the column that would be honored by the sort routine irrespective of the values contained in the column. Values would be any valid data type. sortNullCollatingSequence - This would define whether nulls get sorted to the top or bottom of the list. Values would be low - which would indicate that nulls would sort lower than the lowest normal value, and high - which would indicate that nulls would sort higher than the highest normal value. This is one possible solution, there may be better ones but in my opinion the current method should be improved. I would like to see it implemented quickly as I believe it is a serious problem. How do I go about getting this taken seriously, and not assigned an "enhancement request number" and never looked at again? Paul
