Does pattern validation differs in XSD?

Question

I am trying to validate a XML element with XSD pattern validation using below pattern and it's not working. The required behavior is to allow all characters excepts the ones mentioned in pattern expression.

<xsd:pattern value="^[^&gt;&lt;{}|^`\[\]\\\\]*$"/>

Valid data : TESTING
Invalid data : TE{ST]`I<NG

But above pattern is giving validation error for valid data(TESTING) also in XSD but same works fine if I use this pattern in java regualr expression match package. Please help.

Your character class is possibly not valid, or at least is not doing what you think. `[>]` means match any of `&`, `g`, `t`, `;`. It does not mean match the HTML symbol `>`. — Tim Biegeleisen, Jun 25 '19 at 05:03
@TimBiegeleisen You can't use `<` and `>` literals in XML. Need to use the entities instead. — Robby Cornelissen, Jun 25 '19 at 05:06
@RobbyCornelissen OK...but is that character class valid? I've never seen a flavor of regex which allows for multiple characters. — Tim Biegeleisen, Jun 25 '19 at 05:07
@TimBiegeleisen That character class is valid and will work as intended. The problem is with the `^` and `$` anchors. — Robby Cornelissen, Jun 25 '19 at 05:17
I learn something new every day ^ ^. So, the parser probably converts `>` into `>` internally, to use in the class. — Tim Biegeleisen, Jun 25 '19 at 05:18

Robby Cornelissen · Accepted Answer · 2019-06-25T05:29:40.250

Unlike stated in multiple comments and answers to this question, entities like > and < can be used without any problems in XML Schema regular expressions.

However, anchors like the caret (^) and dollar ($) are not supported.

Given the following schema, with the anchors removed from the pattern:

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" > 
  <xsd:element name="test" type="test"/> 

  <xsd:simpleType name="test"> 
    <xsd:restriction base="xsd:string"> 
      <xsd:pattern value="[^&gt;&lt;{}|^`\[\]\\\\]*"/> 
    </xsd:restriction> 
  </xsd:simpleType> 
</xsd:schema>

This will validate correctly:

<test>testing</test>

While these will not:

<test>{testing</test>

<test>&gt;testing</test>

Does pattern validation differs in XSD?

1 Answers1