XSD/XML Schemas: resolving `Namespace ” is not available to be referenced in this schema` (via: StackOverflow)
Posted by jpluimers on 2013/09/01
While working on my Delphi: First try on an XSD for .groupproj files, I bumped into an error `Namespace ” is not available to be referenced in this schema`.
I added a targetNamespace attribute to the GroupProj.xsd so the .grouproj files would use the right namespace.
That resulted into two funny errors:
- Namespace ” is not available to be referenced in this schema.
Visual Studio (which I normally use for editing XSD) would only throw this error on these elements:
<xsd:element ...>
So it would not throw them on nodes using the empty namespace.
That was really confusing! - When validating .grouproj files using this GroupProj.xsd, I would get this error for all .groupproj files:
System.Xml.Schema.XmlSchemaValidationException: Type ‘<type>’ is not declared. (in this case for ‘<type>’ ‘ProjectType’).
That was odd too: the ‘ProjectType’ was indeed declared, and should be valid.
I could hardly find any information about the latter error, but the former gave a few useful hits.
Thanks User weston – Stack Overflow. for answering this: it made me smack to my head (like usual, a case of EBCAK).
To resolve Namespace ” is not available to be referenced in this schema. You can set the default ” namespace without the need to change the rest of the file:
So after adding the below default xmlns to the XSD, not only the first, but also the second error were gone!
xmlns="http://schemas.microsoft.com/developer/msbuild/2003"
This is the work in progress on GroupProj.xsd:
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| <?xml version="1.0" encoding="utf-8"?> | |
| <!– This very small subset of "http://schemas.microsoft.com/developer/msbuild/2003". | |
| Normally that namespace is defined in Microsoft.Build.xsd/Microsoft.Build.Core.xsd/Microsoft.Build.Commontypes.xsd. | |
| Actually this subset is not a trimmed down version of the original, but started from scracth to | |
| only contains types used by Delphi/RAD Studio/C++ Builder. | |
| In the future, I might add some better restrictions here and there, but so far it is sufficient engough to | |
| – validate .groupproj documents | |
| – use the Delphi XML Data Binding Wizard to generate a Delphi unit that allows generation and reading of .groupproj files. | |
| The default values for `minOccurs` and `maxOccurs` are 1, so make `maxOccurs` larger to allow `repeating` in the Delphi XML Data Binding Wizard. | |
| –> | |
| <xsd:schema attributeFormDefault="unqualified" elementFormDefault="qualified" version="1.0" | |
| targetNamespace="http://schemas.microsoft.com/developer/msbuild/2003" | |
| xmlns="http://schemas.microsoft.com/developer/msbuild/2003" | |
| xmlns:xsd="http://www.w3.org/2001/XMLSchema"> | |
| <xsd:element name="Project" type="ProjectType"/> | |
| <xsd:complexType name="ProjectType"> | |
| <xsd:sequence> | |
| <xsd:element name="PropertyGroup" type="PropertyGroupType"/> | |
| <!– Delphi XE2 sometimes has an empty `ItemGroup` element –> | |
| <xsd:element name="ItemGroup" type="ItemGroupType" minOccurs="0" maxOccurs="unbounded"/> | |
| <xsd:element name="ProjectExtensions" type="ProjectExtensionsType"/> | |
| <xsd:element name="Target" type="TargetType" maxOccurs="unbounded"/> | |
| <xsd:element name="Import" type="ImportType"/> | |
| </xsd:sequence> | |
| </xsd:complexType> | |
| <xsd:complexType name="ImportType"> | |
| <xsd:attribute name="Project" type="xsd:string"/> | |
| <xsd:attribute name="Condition" type="xsd:string"/> | |
| </xsd:complexType> | |
| <xsd:complexType name="TargetType"> | |
| <xsd:sequence> | |
| <xsd:choice> | |
| <xsd:element name="MSBuild" type="MSBuildType"/> | |
| <xsd:element name="CallTarget" type="CallTargetType"/> | |
| </xsd:choice> | |
| </xsd:sequence> | |
| <xsd:attribute name="DependsOnTargets" type="xsd:string" use="optional"/> | |
| <xsd:attribute name="Name" type="xsd:string"/> | |
| </xsd:complexType> | |
| <xsd:complexType name="MSBuildType"> | |
| <xsd:attribute name="Projects" type="xsd:string"/> | |
| <!– http://www.infopathdev.com/blogs/greg/archive/2004/09/16/The-Difference-Between-Optional-and-Not-Required.aspx –> | |
| <xsd:attribute name="Targets" type="xsd:string" use="optional"/> | |
| </xsd:complexType> | |
| <xsd:complexType name="CallTargetType"> | |
| <xsd:attribute name="Targets" type="xsd:string"/> | |
| </xsd:complexType> | |
| <xsd:complexType name="ProjectExtensionsType"> | |
| <xsd:sequence> | |
| <xsd:element name="Borland.Personality" type="xsd:string"/> | |
| <xsd:element name="Borland.ProjectType" type="xsd:string"/> | |
| <xsd:element name="BorlandProject" type="BorlandProjectType"/> | |
| </xsd:sequence> | |
| </xsd:complexType> | |
| <xsd:complexType name="BorlandProjectType"> | |
| <xsd:choice> | |
| <xsd:sequence> | |
| <xsd:element name="Default.Personality" type="xsd:string"/> | |
| </xsd:sequence> | |
| <!– Delphi 2010 can have a nested `BorlandProject` element –> | |
| <xsd:element name="BorlandProject" type="BorlandProjectType"/> | |
| </xsd:choice> | |
| </xsd:complexType> | |
| <xsd:complexType name="ItemGroupType"> | |
| <xsd:sequence> | |
| <xsd:element name="Projects" type="ProjectsType" minOccurs="0" maxOccurs="unbounded"/> | |
| </xsd:sequence> | |
| </xsd:complexType> | |
| <xsd:complexType name="ProjectsType"> | |
| <xsd:sequence> | |
| <xsd:element name="Dependencies" type="xsd:string"/> | |
| </xsd:sequence> | |
| <xsd:attribute name="Include" type="xsd:string"/> | |
| </xsd:complexType> | |
| <xsd:complexType name="PropertyGroupType"> | |
| <xsd:sequence> | |
| <xsd:element name="ProjectGuid" type="guid"/> | |
| </xsd:sequence> | |
| </xsd:complexType> | |
| <xsd:simpleType name="guid"> | |
| <xsd:annotation> | |
| <xsd:documentation xml:lang="en"> | |
| The representation of a GUID, generally the id of an element. | |
| </xsd:documentation> | |
| </xsd:annotation> | |
| <xsd:restriction base="xsd:string"> | |
| <xsd:pattern value="\{[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}\}"/> | |
| </xsd:restriction> | |
| </xsd:simpleType> | |
| </xsd:schema> |
–jeroen
via: How do I use inheritance (ie xs:extension) in my own xml schema? – Stack Overflow.
The Wiert Corner - irregular stream of stuff 
uligerhardt said
s/through/throw/ please. :-)
jpluimers said
Thanks: fixed. I was pretty tired writing that (: