XML schema restriction pattern for not allowing empty strings

Question

In my XML schema I have element of type string that I don't want to be empty (if it contains white-spaces etc I also consider it empty)

I applied restrinction I found at http://blogs.msdn.com/b/neerajag/archive/2005/08/12/450723.aspx

<xsd:restriction base = "xsd:string">
  <xs:minLength value="1" />
  <xs:pattern value=".*[^\s].*" />
</xsd:restriction>

What exactly does that pattern do and will do what I expect?

Answer 1

doesn't this do exactly what you want?

 <xs:restriction base="xs:token">
  <xs:minLength value="1"/>
 </xs:restriction>

If the string contains only whitespace (line feeds, carriage returns, tabs, leading and trailing spaces), the processor will remove them so validation will fail; if there's anything else, validation will succeed. (note though: internal sequences of two or more spaces will be removed - make sure you're ok with that)

Answer 2

The pattern:

• zero or more characters .* (. matches any character).
• matches something not in the listed set of characters. \s is whitespace, so [^\s] is "match something that isn't a whitespace. The initial ^ in the match negates the normal match any one of these characters.
• zero or more characters.