xmlxsd

what is the xsd format to validate for placeholder substitution

I want to be able to specify a attribute in xml can be a specific value or an xml substitution

e.g.

<my_element value1="barney" value2="${otherPerson}" />

I tried

  <xs:simpleType name="MyTypeWithPlaceholder">
    <xs:union memberTypes="MyType PlaceholderType"/>
  </xs:simpleType>

  <xs:simpleType name="MyType ">
    <xs:restriction base="xs:string">
      <xs:enumeration value="barney"/>
      <xs:enumeration value="fred"/>
      <xs:enumeration value="wilma"/>
      <xs:enumeration value="betty"/>
    </xs:restriction>
  </xs:simpleType>

  <xs:simpleType name="PlaceholderType">
    <xs:restriction base="xs:string">
      <xs:pattern value="\$\{[a-z][A-Z]\}"/>
    </xs:restriction>
  </xs:simpleType>

That did not seem to work.

Or is this out of scope with XML and the tools I am using should just recognize the ${xyz} is a variable?

Solution

  • You need a quantifier on the letter ranges, to indicate that they can occur more than just once.

    And when you have the lower-case range followed by the upper-case range, then the regex is saying there will be one lower-case letter and then one upper-case letter.

    I would combine them and use + to indicate that there must be at least one letter, but could be many:

    \$\{[a-zA-Z]+\}