How to write regex in XSD

Question

I am writing XSD pattern restriction and I have the following strings that are valid

• ^user
• ^user.name
• {$username}
• {$user1.name}

And the below are invalid

• user
• User
• USER
• {username}
• {user@name}

The rule is to start the string with either ^ or {. If we start with { then next character should be $ and the word should end with }. No uppercase or @ symbol allowed.

I have tried this <xs:pattern value="[\\^\\{].*\\w+\\}?"/> this work partially but doesnt satisfy all conditions

Any help is appreciated.

Answer 1

You may use

<xs:attribute name="label">
  <xs:simpleType>
    <xs:restriction base="xs:string">
      <xs:pattern value="\^[a-z]+(\.[a-z]+)?|\{\$[a-z]+(\.[a-z]+)?}"/>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>

XSD regex are always anchored, so the two alternatives in the above regex must match the whole string.

They match

• \\^[az]+(\\.[az]+)? - ^ char, then 1+ lowercase ASCII letters, then an optional sequence of . and 1+ lowercase ASCII letters
• | - or
• \\{\\$ - {$ substring
• [az]+(\\.[az]+)? - 1+ lowercase ASCII letters, then an optional sequence of . and 1+ lowercase ASCII letters
• } - a } char.