Is there a difference between XSD:Pattern and C# Regex?

Question

I can't really go into to much depth of my project for a number of constraining reasons.

Essentially I am trying to pre-validate an object before serializing it and then validating it against a schema. The schema has validation for a name, which I know isn't ideal and your better off not validating a name - but I can't seem to replicate a valid regex for what the schema is trying to do.

<xsd:simpleType name="CharsetD">
  <xsd:restriction base="xsd:string">
    <xsd:pattern value="[A-Za-z \-&apos;]*"/>
  </xsd:restriction>
</xsd:simpleType>

<xsd:element minOccurs="0" maxOccurs="2" name="Fore">
  <xsd:simpleType>
    <xsd:restriction base="CharsetD">
      <xsd:minLength value="1"/>
      <xsd:maxLength value="35"/>
      <xsd:pattern value="[A-Za-z].*"/>
    </xsd:restriction>
  <xsd:simpleType>
</xsd:element>

I simply thought in the above case that I could try and just use the xsd:pattern for the charset.

I tried to use [A-Za-z \-']* which returned a name such as Luke2 as valid, but the schema validation said it wasn't because it contained a number.

My question is, how can I replicate the above in a single c# regex? Also, is there any differences between how the schema pattern operates compared to if I used it in .NET that I can note for the future?

Answer 1

I have found the problem, albeit disguised as I haven't really worked extensively with XML Schema

The difference

The CharsetD type doesn't just use the pattern, as this alone isn't good enough to validate names with numbers, so when I tried to use just the pattern - it allowed numbers. There is a line on the type however which constrains numbers, and therefore why the schema returns an error where the regex doesn't.

<xsd:restriction base="xsd:string">

Solution

I created a different single regex which would cater the string restriction that is applied in my schema.

^[\p{L} \.\-]+$