Need help with (recursive) xsd group - xsd

I have this xsd:
<?xml version="1.0" encoding="utf-8" ?>
<xs:schema xmlns="http://myschema.com/schema"
targetNamespace="http://myschema.com/schema"
xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:complexType name="aType" mixed="true">
<xs:group ref="aElements" minOccurs="0" maxOccurs="unbounded"/>
</xs:complexType>
<xs:group name="aElements">
<xs:choice>
<xs:element name="a" type="aType"/>
</xs:choice>
</xs:group>
<xs:element name="b">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:group ref="aElements"/>
</xs:choice>
</xs:complexType>
</xs:element>
</xs:schema>
and I try to validate this xml document against it:
<?xml version="1.0" encoding="utf-8" ?>
<b xmlns="http://myschema.com/schema">
<a/>
</b>
However, Visual Studio 2008's xml validator complains about the <a> element:
The element 'b' in namespace 'http://myschema.com/schema' has invalid child element 'a' in namespace 'http://myschema.com/schema'. List of possible elements expected: 'a'.
What is the problem?
Edit: Oops, when dumbing down the example I caused forgot to make the element optional inside the element, causing infinite recursion. The problem is still there with this mod, though.
ANSWER: The answer was that the xs:schema tag should include the elementFormDefault="qualified" attribute.

you define aElements with aType, and aType with aElements. i'm not an xsd expert, but how is that supposed to work?

You could make your life much easier using an editor for XSD development. We've been using Liquid XML Studio for ages, it makes life much easer.

Related

Use XML Schema to extend an element with attributes rather than a complexType

So I found this post which is very similar to what I want to achieve, but I can't quite figure out if it's not possible to do what I am attempting, or if I'm just missing something...
Use XML Schema to extend an element rather than a complexType
The gist is that I have an XSD that contains a defined Element. I would prefer not to edit this original xsd file. Is there any way for me to extend the Element so that I also can add my own attributes, "attributeC"?
The other post creates a new complexType of fooType, and places the element inside of it, and extends fooType to contain more elements. By doing so, they are able to achieve an Element that contains fooElement, and two other added elements. The issue is that I'd like to add to the Element itself, not add to the element at the same level.
XSD1
<xs:schema xmlns:bas="http://www.base.com"
xmlns="https://www.adding.com"
attributeFormDefault="qualified"
elementFormDefault="qualified"
targetNamespace="https://www.adding.com"
xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:import schemaLocation="XSD2.xsd" namespace="http://www.base.com" />
<xs:complexType name="FileSpecType">
<xs:sequence>
<xs:element ref="bas:FileSpec"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="FullFileSpecType">
<xs:complexContent mixed="false">
<xs:extension base="FileSpecType">
<xs:attribute name="attributeC" type="xs:string" />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="FileSpec" type="FileSpecType" />
This code ends up generating a new FileSpec
<FileSpec AttributeC="attCval" />>
<bas:FileSpec/>
</FileSpec>
What I want to achieve is more like...
<bas:FileSpec AttributeA="attAval" AttributeB="attBval" AttributeC="attCval/>
Can anybody point me in the right direction to solve my issues?
I'm thinking I could define my own dataType=FileSpec and add my own reference to external attributes, but that'd require manually copying over each attribute that exists in my original XSD2 FileSpec so I'd prefer to avoid that if possible. Then I think I could take that new FileSpec that I created and redefine the older FileSpec with it. Is this possible to do? It sounds like a lot of work that must have a simpler solution.
Its somewhat unclear what you are trying to do, if this does not cover it, please post the schema you are including as well as the XML you are trying to produce including the containing element.
You can extend an existing xs:complexType like this.
<?xml version="1.0" encoding="utf-8" ?>
<!--Created with Liquid Studio 2020 (https://www.liquid-technologies.com)-->
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:complexType name="BaseType">
<xs:attribute name="attributeA" type="xs:string" />
</xs:complexType>
<xs:complexType name="ExtendedType">
<xs:complexContent>
<xs:extension base="BaseType">
<xs:attribute name="attributeB" />
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="RootElm">
<xs:complexType>
<xs:sequence>
<xs:element name="BaseElm" type="BaseType" />
<xs:element name="ExtendedElm" type="ExtendedType" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
This allows you to produce XML that looks like this
<?xml version="1.0" encoding="utf-8"?>
<!-- Created with Liquid Studio 2020 (https://www.liquid-technologies.com) -->
<RootElm xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<BaseElm attributeA="XX" />
<ExtendedElm attributeA="YY" attributeB="ZZ" />
</RootElm>
There is another way to make use of the ExtendedType when ever its valid to use a BaseType
<?xml version="1.0" encoding="utf-8"?>
<!-- Created with Liquid Studio 2020 (https://www.liquid-technologies.com) -->
<RootElm xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<BaseElm xsi:type="ExtendedType" attributeB="XX" attributeA="YY" />
<ExtendedElm attributeA="XX" attributeB="YY" />
</RootElm>
Notice the xsi:type="ExtendedType" in the BaseElm, this tells the XML processor that this element actually contains data for the ExtendedType.

How do I define one-to-many relationships across different XSD Files, and why does xs:extends not work in this situation?

I have been developing some xml schema files over the past few days, and learned of a specific element to extend simpletypes and complextype elements.
I am currently using the visual studio 2012 professional edition, and I am currently testing relationships of XSD files (I daresay parent-child relationships , or one to many relationships) between these files, for example (I am using objects from Google DFA API):
RichMediaAsset
∟ RichMediaExpandingHtmlAsset
∟ RichMediaExpandingHtmlAsset
∟ RichMediaFloatingHtmlAsset
...
All these classes "extend" or "Inherit" from RichMediaAsset (which is the base, or abstract). I have defined RichMediaAsset as the following in XSD
<?xml version="1.0" standalone="yes"?>
<xs:schema id="RedirectCreativeBase" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<!-- simpleTypes=primitive -->
<!-- extBooleanMethodPrefix=is -->
<xs:complexType name="RichMediaAssetWrapper" abstract="true">
<xs:sequence>
<xs:element name="fileName" type="xs:string" minOccurs="0" />
<xs:element name="fileSize" type="xs:int" minOccurs="0" />
<xs:element name="id" type="xs:long" minOccurs="0" />
<xs:element name="parentAssetId" type="xs:long" minOccurs="0" />
<xs:element name="type" type="xs:string" minOccurs="0" />
</xs:sequence>
</xs:complexType>
</xs:schema>
I have defined the second file, RichMediaExpandingHtmlAsset as follows:
<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="RichMediaExpandingHtmlAssetWrapper" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:include schemaLocation="./RichMediaAsset.xsd"/>
<xs:complexType name="RichMediaExpandingHtmlAssetWrapper" abstract="false" >
<xs:extension base="RichMediaAssetWrapper"> <!-- Not happy here -->
<xs:sequence>
<!-- content to be included,extending RichMediaAsset's complex type called RichMediaAssetWrapper -->
</xs:sequence>
</xs:extension>
</xs:complexType>
</xs:schema>
The part which I mentioned VS2012 is not happy with is defined as follows:
Warning 1 The 'http://www.w3.org/2001/XMLSchema:extension' element is not supported in this context. C:\eclipse\Workspace\aem_adservices_google_dfa\aem.adservices.google.dfa\xsd\Creative\RichMediaExpandingHtmlAsset.xsd 5 6 Miscellaneous Files
Warning 2 The element 'complexType' in namespace 'http://www.w3.org/2001/XMLSchema' has invalid child element 'extension' in namespace 'http://www.w3.org/2001/XMLSchema'. List of possible elements expected: 'annotation, simpleContent, complexContent, group, all, choice, sequence, attribute, attributeGroup, anyAttribute' in namespace 'http://www.w3.org/2001/XMLSchema'. C:\eclipse\Workspace\aem_adservices_google_dfa\aem.adservices.google.dfa\xsd\Creative\RichMediaExpandingHtmlAsset.xsd 5 6 Miscellaneous Files
The question now: Is this a possible bug of 2012, have I made an error, is this simply not supported (even though I checked the usage examples at w3schools.com), or is there better ways for me to define the one to many relationships?
I found the issue with my XSD. It was in fact missing a tag. In these cases, xs:complexContent or xs:simpleContent must be defined in order to define extensions or restrictions on a complex/simple type respectively that contains mixed content or elements only.
Here is my solution, and the errors in my code also disappeared.
<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="RichMediaExpandingHtmlAssetWrapper" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:include schemaLocation="./RichMediaAsset.xsd"/>
<xs:complexType name="RichMediaExpandingHtmlAssetWrapper" abstract="false" >
<xs:complexContent>
<xs:extension base="RichMediaAssetWrapper">
<xs:sequence>
...
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
</xs:schema>
Sources: ComplexContent; SimpleContent

XSD my data type

I would like to ask about .XSD document. I cannot find anything about creating my own type, for example:
<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:complexType name="Client">
<xs:sequence>
<xs:element name="FirstName" type="string"/>
<xs:element name="SecondName" type="string"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="Contact">
<xs:sequence>
<xs:element name="contacts" type="Client" minOccurs="1"/>
</xs:sequence>
</xs:complexType>
</xsd:schema>
And I would like to know is that right way to define my own type contact?
A few points that were not quite right.
The xsd: namespace alias on the closing schema tag should be just xs:
The primitive string types need there types qualifying, ie xs:string.
From a style point of view ComplexTypes should end Type.
If you want to use the schema (presumably via the Contact) then you need to declare a root element.
<?xml version="1.0" encoding="utf-8" ?>
<!--Created with Liquid XML Studio 2012 Developer Edition (Trial) 10.0.1.3941 (http://www.liquid-technologies.com)-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:complexType name="ClientType">
<xs:sequence>
<xs:element name="FirstName" type="xs:string" />
<xs:element name="SecondName" type="xs:string" />
</xs:sequence>
</xs:complexType>
<xs:complexType name="ContactType">
<xs:sequence>
<xs:element name="contacts" type="ClientType" minOccurs="1" />
</xs:sequence>
</xs:complexType>
<xs:element name="Client" type="ClientType" />
</xs:schema>
Basically XML Schemas are complex things to write without a tool. I'd seriously look into getting a good schema designer, I'd recommend Liquid XML Studio.

XSD: specify a choice must have at least one from a list but no more than one of each

This has been driving me mad for hours. I've read every relevant XSD question on SO and the rest of the Internet it seems and still the answer eludes me.
I need an XML schema that requires at least one of list of elements be present, but each element may appear only 0 or 1 times.
This is similar to this question:
XML schema construct for "any one or more of these elements but must be at least one"
but I was unable to constrain the upper limit: I am apparently using maxOccursincorrectly.
Here's where I left off with my schema:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:complexType name="Selects">
<xs:sequence minOccurs="2" maxOccurs="4">
<xs:choice>
<xs:element name="aaa" minOccurs="1" maxOccurs="1"/>
<xs:element name="bbb" minOccurs="1" maxOccurs="1"/>
<xs:element name="ccc" minOccurs="1" maxOccurs="1"/>
<xs:element name="ddd" minOccurs="1" maxOccurs="1"/>
</xs:choice>
</xs:sequence>
</xs:complexType>
<xs:element name="baseElement">
<xs:complexType>
<xs:sequence>
<xs:element name="MyChoice" type="Selects"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
I've tried the minOccurs and maxOccurs on the choice and the element with no luck. Here is XML that validates, though I don't want it to:
<?xml version="1.0" encoding="UTF-8"?>
<baseElement xsi:noNamespaceSchemaLocation="myTest.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<MyChoice>
<ddd/>
<ddd/>
</MyChoice>
</baseElement>
Here's an example of what I would like, if possible:
<?xml version="1.0" encoding="UTF-8"?>
<baseElement xsi:noNamespaceSchemaLocation="myTest.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<MyChoice>
<ddd/>
<aaa/>
<ccc/>
</MyChoice>
</baseElement>
I would like it to complain about the multiple ddd elements but allow any or all of the others in any order. I get an error if I only have one element under MyChoice so at least something works.
What am I doing wrong? How do I prevent multiple of the same element from validating?
UPDATE
This was my solution (from comments on answer below):
Actually, xs:all did the trick. I swapped the choice for all and added minOccurs="0" maxOccurs="1" to each element. With xs:all, minOccurs must be either 0 or 1 and maxOccurs must be 1. Thanks for your help - I'm good to go now!
Just move the <xs:sequence minOccurs="2" maxOccurs="4"> from around the choice to the point where you want to use it further down. (you can also remove the min/max occurs = 1 as this is what xs:choice does)
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:complexType name="Selects">
<xs:choice>
<xs:element name="aaa" />
<xs:element name="bbb" />
<xs:element name="ccc" />
<xs:element name="ddd" />
</xs:choice>
</xs:complexType>
<xs:element name="baseElement">
<xs:complexType>
<xs:sequence minOccurs="2" maxOccurs="4">
<xs:element name="MyChoice" type="Selects" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
This validates the following:
<baseElement xsi:noNamespaceSchemaLocation="myTest.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<MyChoice>
<bbb></bbb>
</MyChoice>
<MyChoice>
<ccc></ccc>
</MyChoice>
</baseElement>
UPDATE
I think you are reaching the limit of what you can achieve with XSD. I can't see any way you can do this other than by defining a "version" of the MyChoice type for every single combination possible (which will then need different names MyChoice1, MyChoice2 etc)
You can also use xs:all
<xs:complexType name="Selects">
<xs:all minOccurs=2 maxOccurs=4>
<xs:element name="aaa" />
<xs:element name="bbb" />
<xs:element name="ccc" />
<xs:element name="ddd" />
</xs:all>
</xs:complexType>
but this will not prevent you from having four <ddd/>'s

Generate Nested Types instead of Global Types with xsd.exe

Using xsd.exe in a C# class, is there a way to produce a xsd file with Nested Type, instead of Global Types?
I want to use this xsd file, with SSIS - Sql Server Integration Services, and look SSIS is not reading my xsd very well.
I want to generate the xsd like this, with Nested Types :
<?xml version="1.0" encoding="utf-8"?>
<xs:schema targetNamespace="http://tempuri.org/XMLSchema.xsd" elementFormDefault="qualified" xmlns="http://tempuri.org/XMLSchema.xsd" xmlns:mstns="http://tempuri.org/XMLSchema.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="Country">
<xs:complexType>
<xs:sequence>
<xs:element name="City">
<xs:complexType>
<xs:sequence>
<xs:element name="CityName" type="xs:string" />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="CoutryName" type="xs:string" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
but xsd.exe produce this , with Global Types, and SSIS don't read it. I need to change this xsd manually to be like above.
<?xml version="1.0" encoding="utf-8"?>
<xs:schema targetNamespace="http://tempuri.org/XMLSchema.xsd" elementFormDefault="qualified" xmlns="http://tempuri.org/XMLSchema.xsd" xmlns:mstns="http://tempuri.org/XMLSchema.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="Country">
<xs:complexType>
<xs:sequence>
<xs:element name="City" type="City">
</xs:element>
<xs:element name="CoutryName" type="xs:string" />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:complexType name="City">
<xs:sequence>
<xs:element name="CityName" type="xs:string" />
</xs:sequence>
</xs:complexType>
</xs:schema>
Any suggestion? Or other tool that I can use.
Thanks a lot.
I'll further assume that not "very well" means you're not seeing CountryName in your XML Source output.
The documentation on MSDN is a good reading, although in my opinion it fails to describe why you would encounter the behavior you see.
I believe that it has to do with the way XML Source outputs are being determined. SSIS infers a data set from the XML structure; the top level entity, that corresponds to the root element, is not mapped to an output, so all the attributes associated with it, in your case CountryName, will not show up.
The easiest way to prove it, is to add another root element that wraps your Country (equivalent to having a dummy "root" class that has a Country-type property).
<xs:element name="root">
<xs:complexType>
<xs:sequence>
<xs:element ref="Country"/>
</xs:sequence>
</xs:complexType>
</xs:element>
If you add the above schema fragment to your schema, you should get your expected results. At the beginning I thought that it has to do with the issue described here; while you can still use the tool to visualize the data set as described by the MSDN link above, in your case, the authoring style you suggested (basically a russian-doll) can't change the outcome.

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