I may be being stupid but the current Date Class does not appear to protect 
itself against a ByteString that is not in valid date format, e.g. by raising 
an Error.

 

e.g. the code  ‘ABC’ asDate opens the Debugger on #isLetter was sent to nil 
because it appears to expect more letters after $C but the peek returns nil 
instead.

This seems to me to require a more defensive programming approach.

 

I would like to validate a user input as a valid date in a number of different 
formats before converting it to a Date and storing it in my model.

 

I’ve tried using the Date parser, e.g.

 

Date readFrom: '04/02/2013' readStream pattern: 'dd/mm/yyyy'.

 

 

This is fine for simply parsing a valid string but rates a DateError if it 
doesn’t match the .  So entering ‘04/13/2013’ cleverly raises ‘DateError: There 
is no 13th month’.

 

My thought was I could use this to return a simple true/false result in a 
ByteString extension in my application for example as follows:

 

ByteString >> isValdiDate

 

(Date readFrom: self pattern: ‘dd/mm/yyyy’) on: DateError do: [^ false].

^ true

 

However this doesn’t intercept the DateError which is simply reported in the 
Debugger as before.   This may be my lack of uncderstaning of the Exception 
handling in Pharo.

 

Any and all thoughts welcome.

 

R

 

 

 

 

 

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