delphi dbgrid boolean value, accept f fa fal fals false , how to accept more values?

Question

I'm using mssql and Delphi 2009. When a form contains a dbgrid that is connected to boolean field, the values are displayed as True, or False. The Delphi dbgrid has the ability to translate

f
fa
fal
fals
false
t
tr
tru
true

to be true or false. I want to add values so it can accept other strings, and match them to true or false. Where could these values be added?

Answer 1

This is the default behavior for TBooleanField.DisplayValues. Look at the db unit source:
db.TBooleanField.SetAsString and db.TBooleanField.SetDisplayValues.

If you set TField.DisplayValues := 'Yes;No'; for example: Y, Ye, Yes will represent True; N, No will represent False.

You cannot add more values to it. Unless you utilize OnSetText as suggested by the other answer, or use a TDbGrid.PickList.

Personally, I would use a CheckBox for Boolean field value representation on the TDBGrid.
There are plenty of examples out there on how to do that.

Answer 2

You could write an OnSetText event for your boolean field, and interpret any given text as True or False.