I would like to validate the following conditions on a numeric field:
1) That the user did not enter a non-numeric string where he was
required to enter a number.
2) That the numeric value is zero or greater.
There seems to be a conflict between these two requirements:
If the user enters a non-numeric string (e.g "ABC"), by the time it
reaches the validation function within the ActiveRecord object, it has
already been marshalled into a numeric format. "ABC" will be converted
to zero. According to condition #2, this is an acceptable value.
According to condition #1, it is not.
Is there anyway I can execute the validation methods on the raw string
values, before they are "casted" into the ActiveRecord types?
Otherwise, can you suggest an elegant solution for this problem?