regular expression for date format itself in XSD pattern restriction

Question

I am trying to make a regular expression for date format in XSD 1.0 pattern restriction.

I want to check if the date 'format' is invalid, NOT date value.

Date format I want to check are;

Year:  YYYY or YY
Month: MM or M or MMM or MMMM
Day: D or DD
and has zero or unbounded of . / ; (just space) ! @

For example, below value is vaild;

MMM. D. YYYY
MM/DD/YYYY
DD/MM.YYYY
YYMM DD

below is not valid;

dd%mmYYYY
20140404
YYYY-MM-YYYY-DD

I made a regular expression but have a problem. It checks 'YYYY-MM-YYYY' as valid (YYYY is repeated)

([!@#%_\-=`~,\.\/;: ]*(YYYY|YY|M|MM|MMM|MMMM|D|DD)[!@#%_\-=`~,\.\/;: ]*)+

How can I make the regular expression check if there is only one YYYY|YY|M|..D|DD?

XML schema 1.0 / Xercers-J

Answer 1

OK, as much as it puts a bad taste in my mouth to even paste this into the answer box, I think this may be what you're looking for (your scroll bar is going to get a reasonable workout today)...

(([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(DD?)?)?)?)?))|([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(M{1,4})?)?)?)?))|([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(YY(YY)?)?)?)?)?))|([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(DD?)?)?)?)?))|([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(M{1,4})?)?)?)?))|([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(YY(YY)?)?)?)?)?)))[!@#%_\-=`~,\.\/;: ]*

Got all that? This is it broken down into the 9 possibilities of the order in which the token types (Year, Month or Day) can appear (if I understand you correctly)... I can explain if you ask, but don't wanna waste time if nobody is interested - even someone stumbling on this answer and commenting and asking for an explanation is enough - just let me know.

(

([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(DD?)?)?)?)?))|

([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(M{1,4})?)?)?)?))|

([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(YY(YY)?)?)?)?)?))|

([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(DD?)?)?)?)?))|

([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(YY(YY)?([!@#%_\-=`~,\.\/;: ]*(M{1,4})?)?)?)?))|

([!@#%_\-=`~,\.\/;: ]*(DD?([!@#%_\-=`~,\.\/;: ]*(M{1,4}([!@#%_\-=`~,\.\/;: ]*(YY(YY)?)?)?)?)?))

)[!@#%_\-=`~,\.\/;: ]*