Cannot resolve the ‘schemaLocation’ attribute

Question

Cannot resolve the ‘schemaLocation’ attribute

Vijay Singh 21

Platform : Windows Server 2019, .NET Framework 4.6.1, Visual Studio 2019

Hi,

I am getting warning Cannot resolve the ‘schemaLocation’ attribute while loading xsd file UBL-SignatureAggregateComponents-2.1.xsd
in XmlSchemaSet

This is my code to load xsd

   public void OpenXSD(string filename, out string result)  
    {  
        private XmlSchemaSet m_schemaSet;  

        result = "";  
        //create xml reader  
        XmlReader reader = XmlReader.Create(filename);  

        if (reader == null)  
        {  
            result = "Cannot Create instance of XmlReader, please select the valid XSD schema file";  
            return;  
        }  
        //create schema from reader with validation callback  
        XmlSchema schema = XmlSchema.Read(reader, new ValidationEventHandler(ValidationCallback));  


        //Add schema to XmlSchemaSet  
        m_schemaSet.Add(schema);  

        //compile XmlSchemaSet  
        if (!m_schemaSet.IsCompiled)  
            m_schemaSet.Compile();  

        //return the result of compile  
        if (m_msg == "ok")  
            result = schema.TargetNamespace;  
        else  
            result = "Error : " + m_msg;  

        if (reader != null)  
            reader.Close();  

        m_msg = "ok";  
    }

While loading file UBL-SignatureAggregateComponents-2.1.xsd this file is importing file UBL-xmldsig-core-schema-2.1.xsd. Some how this file is not getting loaded which has been marked as bold italic text below.

<xsd:import namespace="http://www.w3.org/2000/09/xmldsig#"
schemaLocation="UBL-xmldsig-core-schema-2.1.xsd"/>

When I import file UBL-xmldsig-core-schema-2.1.xsd individually our program is successful.

Exception detail

In the exception detail you can see Xml_DtdIsProhibitedEx for the file UBL-xmldsig-core-schema-2.1.xsd. Please suggest how this issue can be resolve.

How to change c# code so that file UBL-xmldsig-core-schema-2.1.xsd get loaded in UBL-SignatureAggregateComponents-2.1.xsd successfully?

Thanks and regards,
Vijay

Here I have added content of file UBL-xmldsig-core-schema-2.1.xsd and UBL-xmldsig-core-schema-2.1.xsd.

Content of file UBL-SignatureAggregateComponents-2.1.xsd

<xsd:schema xmlns="urn:oasis:names:specification:ubl:schema:xsd:SignatureAggregateComponents-2"
xmlns:sac="urn:oasis:names:specification:ubl:schema:xsd:SignatureAggregateComponents-2"
xmlns:sbc="urn:oasis:names:specification:ubl:schema:xsd:SignatureBasicComponents-2"
xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
xmlns:ccts="urn:un:unece:uncefact:documentation:2"
targetNamespace="urn:oasis:names:specification:ubl:schema:xsd:SignatureAggregateComponents-2"
elementFormDefault="qualified"
attributeFormDefault="unqualified"
version="2.1">

<xsd:import namespace="urn:oasis:names:specification:ubl:schema:xsd:SignatureBasicComponents-2"
schemaLocation="UBL-SignatureBasicComponents-2.1.xsd"/>
<xsd:import namespace="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2"
schemaLocation="UBL-CommonBasicComponents-2.1.xsd"/>

<xsd:import namespace="http://www.w3.org/2000/09/xmldsig#"
schemaLocation="UBL-xmldsig-core-schema-2.1.xsd"/>

<xsd:import namespace="http://uri.etsi.org/01903/v1.3.2#"
schemaLocation="UBL-XAdESv132-2.1.xsd"/>
<xsd:import namespace="http://uri.etsi.org/01903/v1.4.1#"
schemaLocation="UBL-XAdESv141-2.1.xsd"/>

<xsd:element name="SignatureInformation" type="SignatureInformationType"/>


<xsd:complexType name="SignatureInformationType">
<xsd:annotation>
<xsd:documentation>
<ccts:Component>
<ccts:ComponentType>ABIE</ccts:ComponentType>
<ccts:DictionaryEntryName>Signature Information. Details</ccts:DictionaryEntryName>
<ccts:Definition>This class captures a single signature and optionally associates to a signature in the document with the corresponding identifier.</ccts:Definition>
<ccts:ObjectClass>Signature Information</ccts:ObjectClass>
</ccts:Component>
</xsd:documentation>
</xsd:annotation>
<xsd:sequence>
<xsd:element ref="cbc:ID" minOccurs="0" maxOccurs="1">
<xsd:annotation>
<xsd:documentation>
<ccts:Component>
<ccts:ComponentType>BBIE</ccts:ComponentType>
<ccts:DictionaryEntryName>Signature Information. Identifier</ccts:DictionaryEntryName>
<ccts:Definition>This specifies the identifier of the signature distinguishing it from other signatures.</ccts:Definition>
<ccts:Cardinality>0..1</ccts:Cardinality>
<ccts:ObjectClass>Signature Information</ccts:ObjectClass>
<ccts:PropertyTerm>Identifier</ccts:PropertyTerm>
<ccts:RepresentationTerm>Identifier</ccts:RepresentationTerm>
<ccts:DataType>Identifier. Type</ccts:DataType>
</ccts:Component>
</xsd:documentation>
</xsd:annotation>
</xsd:element>
<xsd:element ref="sbc:ReferencedSignatureID" minOccurs="0" maxOccurs="1">
<xsd:annotation>
<xsd:documentation>
<ccts:Component>
<ccts:ComponentType>BBIE</ccts:ComponentType>
<ccts:DictionaryEntryName>Signature Information. Referenced Signature Identifier. Identifier</ccts:DictionaryEntryName>
<ccts:Definition>This associates this signature with the identifier of a signature business object in the document.</ccts:Definition>
<ccts:Cardinality>0..1</ccts:Cardinality>
<ccts:ObjectClass>Signature Information</ccts:ObjectClass>
<ccts:PropertyTerm>Referenced Signature Identifier</ccts:PropertyTerm>
<ccts:RepresentationTerm>Identifier</ccts:RepresentationTerm>
<ccts:DataType>Identifier. Type</ccts:DataType>
</ccts:Component>
</xsd:documentation>
</xsd:annotation>
</xsd:element>
<xsd:element ref="ds:Signature" minOccurs="0" maxOccurs="1">
<xsd:annotation>
<xsd:documentation>This is a single digital signature as defined by the W3C specification.</xsd:documentation>
</xsd:annotation>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
</xsd:schema>

Content of file UBL-xmldsig-core-schema-2.1.xsd

<?xml version="1.0" encoding="utf-8"?>
<!--
Library: OASIS Universal Business Language (UBL) 2.1 OS
http://docs.oasis-open.org/ubl/os-UBL-2.1/
Release Date: 04 November 2013
Module: UBL-xmldsig-core-schema-2.1.xsd
Generated on: 2010-08-13 19:10(UTC)

This is a copy of http://www.w3.org/TR/xmldsig-core/xmldsig-core-schema.xsd
modified only to remove these PUBLIC and SYSTEM identifiers from the DOCTYPE:

    PUBLIC "-//W3C//DTD XMLSchema 200102//EN"   
           "http://www.w3.org/2001/XMLSchema.dtd"

-->
<!DOCTYPE schema
[
<!ATTLIST schema
xmlns:ds CDATA #FIXED "http://www.w3.org/2000/09/xmldsig#">
<!ENTITY dsig 'http://www.w3.org/2000/09/xmldsig#'>
<!ENTITY % p ''>
<!ENTITY % s ''>
]>

<!-- Schema for XML Signatures
http://www.w3.org/2000/09/xmldsig#
$Revision: 1.1 $ on $Date: 2002/02/08 20:32:26 $ by $Author: reagle $

Copyright 2001 The Internet Society and W3C (Massachusetts Institute  
of Technology, Institut National de Recherche en Informatique et en  
Automatique, Keio University). All Rights Reserved.  
http://www.w3.org/Consortium/Legal/  

This document is governed by the W3C Software License [1] as described  
in the FAQ [2].  

[1] http://www.w3.org/Consortium/Legal/copyright-software-19980720  
[2] http://www.w3.org/Consortium/Legal/IPR-FAQ-20000620.html#DTD

-->

</schema>

2 answers

Your answer

Answer 1

Hello @Vijay Singh ,

When you're using embedded files, the default XmlTextReader is not able to find referenced files. After creating the XmlTextReader, you must supply it with a XmlResolver that is aware of handling embedded files.
To get rid of the error, change type="Addresses" to name="Addresses" in your PERSON.xsd file.
It is better to go with the code below to get schemas compiled. The important things are to make sure you establish a base uri (since you're reading from a stream), to use an XmlSchemaSet instead, and a custom resolver (to read files as embedded resources).
https://stackoverflow.com/questions/33476683/compiling-two-embedded-xsds-error-cannot-resolve-schemalocation-attribute
https://stackoverflow.com/questions/7982275/how-can-i-resolve-the-schemalocation-attribute-of-an-xsd-when-all-of-my-xsds

Other references:
https://stackoverflow.com/questions/7982275/how-can-i-resolve-the-schemalocation-attribute-of-an-xsd-when-all-of-my-xsds
https://stackoverflow.com/questions/4584080/schema-validation-xml
https://learn.microsoft.com/en-us/dotnet/api/system.xml.xmlreader.create?view=net-5.0

Best regards,
Leila

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Answer 2

Leila Kong 3,706

Hello @Vijay Singh ,

Just checking in to see if the information provided was helpful.
Please post back at your convenience if we can assist further.

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Cannot resolve the ‘schemaLocation’ attribute

2 answers

Your answer