Question

I am trying to read an XSD file using Nokogiri Ruby parser and it throws following error
Nokogiri::XML::SyntaxError (Element ‘{http://www.w3.org/2001/XMLSchema}element’: The content is not valid. Expected is (annotation?, ((simpleType | complexType)?, (unique | key | keyref)*)).):

Does any one know what is wrong with the xsd?

<?xml version="1.0" encoding="utf-8"?>
<xsd:schema elementFormDefault="qualified" version="1.0" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:element name="company_donation_request" type="company_donation_requestType" />
  <xsd:complexType name="company_donation_requestType">
    <xsd:sequence>
      <xsd:element name="order" type="orderType"></xsd:element> 
      <xsd:element name="donation" type="donationType"></xsd:element>
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="donationType">
    <xsd:sequence>
      <xsd:element name="campaign_key" type="xsd:string" minOccurs="1" maxOccurs="1" >
        <xsd:restriction base="xsd:string">
            <xsd:minLength value="2"/>
            <xsd:maxLength value="255"/>
        </xsd:restriction>
      </xsd:element>
      <xsd:element name="amount" type="xsd:decimal" minOccurs="1" maxOccurs="1" ></xsd:element>
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="orderType">
    <xsd:sequence>
      <xsd:element name="id" type="xsd:string" minOccurs="1" maxOccurs="1" >
        <xsd:restriction base="xsd:string">
            <xsd:minLength value="2"/>
            <xsd:maxLength value="255"/>
        </xsd:restriction>
      </xsd:element>
      <xsd:element name="fulfillment_date" type="xsd:dateTime" minOccurs="1" maxOccurs="1" >
        <xsd:restriction base="xsd:string">
            <xsd:minLength value="2"/>
            <xsd:maxLength value="255"/>
        </xsd:restriction>
      </xsd:element>
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>

Answer 1

You’re getting the error because xsd:restriction is not allowed as a child of xsd:element. Try adding your xsd:restriction to an xsd:simpleType and then specifying that type in your xsd:element.

You could add the xsd:simpleType directly to the xsd:element, but since you’re using the same restriction 3 times, it makes more sense to put it in a simpleType outside of the elements.

Here’s an example. I named the simpleType “stackOverflowTest”:

<xsd:schema elementFormDefault="qualified" version="1.0" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:element name="company_donation_request" type="company_donation_requestType" />
  <xsd:complexType name="company_donation_requestType">
    <xsd:sequence>
      <xsd:element name="order" type="orderType"></xsd:element> 
      <xsd:element name="donation" type="donationType"></xsd:element>
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="donationType">
    <xsd:sequence>
      <xsd:element name="campaign_key" type="stackOverflowTest" minOccurs="1" maxOccurs="1"/>
      <xsd:element name="amount" type="xsd:decimal" minOccurs="1" maxOccurs="1"/>
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="orderType">
    <xsd:sequence>
      <xsd:element name="id" type="stackOverflowTest" minOccurs="1" maxOccurs="1"/>      
      <xsd:element name="fulfillment_date" type="stackOverflowTest" minOccurs="1" maxOccurs="1"/>      
    </xsd:sequence>
  </xsd:complexType>
  <xsd:simpleType name="stackOverflowTest">
    <xsd:restriction base="xsd:string">
      <xsd:minLength value="2"/>
      <xsd:maxLength value="255"/>
    </xsd:restriction>  
  </xsd:simpleType>
</xsd:schema>

Hope this helps.