XML schema of XHTML Basic 1.1 (xhtml-basic11-modules-1.xsd file) contains such a redefine:
<xs:redefine schemaLocation="http://www.w3.org/MarkUp/SCHEMA/xhtml-image-1.xsd">
<xs:annotation>
<xs:documentation>
Image module
Elements defined here:
* img
</xs:documentation>
<xs:documentation source="http://www.w3.org/TR/xhtml-modularization/abstract_modules.html#s_imagemodule"/>
</xs:annotation>
<xs:attributeGroup name="xhtml.img.attlist">
<xs:attributeGroup ref="xhtml.img.attlist">
<xs:annotation>
<xs:documentation>
Original Image Attributes (in Image Module)
</xs:documentation>
</xs:annotation>
</xs:attributeGroup>
</xs:attributeGroup>
</xs:redefine>
Is that any different from simply including the image module? It seams to me like it doesn't change anything, but I'm no XML Schema expert.
My initial answer was:
Including the image module would have added everything that is defined there to the schema, whereas using xsd:redefine only the attributeGroup xhtml.img.attlist is imported.
but it is not the case - everything in the referenced schema is included, so the answer appear to be that there is no reason for that xsd:redefine.
Related
Given a schema that defines an element of a certain type, is it possible to allow that type to be extended, but still have that extension element be strongly typed? In other words, add some kind of extension point that can be used from an external schema to add elements that can only be used in this location?
Let's say the schema looks kinda like:
<xs:schema …>
<xs:element name="Match" type="tns:TNodeConstraint" />
<xs:complexType name="TNodeConstraint">
<xs:group ref="tns:Expression" />
</xs:complexType>
<xs:group name="Expression">
<xs:choice>
<xs:element name="And">
<xs:complexType … />
</xs:element>
<xs:element name="Or">
<xs:complexType … />
</xs:element>
<xs:element name="IsAbstract">
<xs:element name="IsExtern">
<!-- Some kind of extension point? -->
</xs:choice>
</xs:group>
</xs>
Is it possible to extend the Expression group so that a second, external schema could say that I can accept IsMyCustomConstraint here, but not IsMyCustomSortOrder? So this will be valid:
<Match>
<IsAbstract />
<IsExtern />
<IsMyCustomConstraint />
</Match>
But this would be invalid?
<Match>
<IsAbstract />
<IsExtern />
<IsMyCustomSortOrder />
</Match>
I don't want to use xs:any as that would allow putting a "sort order" where a constraint can go.
I can modify the original schema
I'm in control of what the namespaces of IsMyCustomConstraint and IsMyCustomSortOrder would be, and it's not important if they match the original schema or not.
is it possible to allow that type to be extended, but still have that extension element be strongly typed?
Definitely - this is described in detail, with examples, here: https://www.w3.org/TR/2000/WD-xmlschema-0-20000225/#DerivExt. As far as I can tell, you just need to declare one or more complex types that are extensions of your base type 'TNodeConstraint'.
XML schema has a rich set of facilities to support type inheritance including:
abstract base types (base type must be extended or restricted before use)
extension (new type allows more values than the base type)
restriction (new type allows fewer values than the base type)
control of whether further extensions/restrictions are allowed (final/block attributes)
I don't see any need to use a separate XSD for the extensions, although you can if you want to. You may find it useful to know about xsi:type, abstract types and the block/final attributes - all are described the XML Schema Part 0 - Primer mentioned above.
I have the following type in an xsd:
<xs:complexType name="VendorSpecificType">
<xs:sequence>
<xs:any namespace="##any" processContents="skip" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
I created this type in Ecore:
I tried to inject an xml containing the following tags:
<VendorSpecific>
<Vendor ID="1"/>
</VendorSpecific>
But it crashes
org.eclipse.m2m.atl.core.ATLCoreException: Error loading test.xml: org.eclipse.emf.ecore.xmi.FeatureNotFoundException: Feature 'Vendor' not found.
The code used to inject models in metamodels is tested and working.
Even this test.xml is loaded correctly if I remove the Vendor tag.
My question is how to map the xsd any to an ecore type so it can be loaded?
UPDATE:
After debugging, it seems that the code I use to inject the model into the ecore model is not complete: the extendedmetadata is always null
// Load in metamodel
IReferenceModel metamodel = modelFactory.newReferenceModel();
injector.inject(metamodel, metamodelPath);
model = modelFactory.newModel(metamodel);
injector.inject(model, modelPath);
How do I tell it to load the metadata?
I added the following line
((EMFModelFactory) modelFactory).getResourceSet().getLoadOptions().put(XMLResource.OPTION_EXTENDED_META_DATA, Boolean.TRUE);
before injecting the metamodel.
It works now!
I am a new comer to JaxB World and I am facing one problem w.r.t. unmarshalling of the stored xml content into java class object. Problem description is as follows. Let me know if this is solvable
I have my xsd file which contains following content(this is just a example)
Student info
<xs:complexType name="specialization" abstract="true">
</xs:complexType>
<xs:complexType name="Engineering">
<xs:complexContent>
<xs:extension base="specialization">
<xs:sequence>
<xs:element name="percentage" type="xs:int" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="Medical">
<xs:complexContent>
<xs:extension base="specialization">
<xs:sequence>
<xs:element name="grade" type="xs:string" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Now all the corresponding java classes are generated by compiling the xsd. Now lets assume in my application i will set the specialization attribute of Student info by constructing Engineering class instance. So after all the operation when i save
the xml file that get saved will have the entry like below
<Student>
<Name>Name1</Name>
<Specialization>
<percentage>78<percentage>
</Specialization>
</Student>
Now when the above content goes for unmarshalling, unmarshalling fails saying unexpected element . I guess this is b'cos Specialization element is of type specialization it calls unmarshalling on itself rather than derived object which is stored.
I hope my explanation is clear. Is there any way that we can unmarshall based on derived class instanse type. The xsd and bindings.xjb file is completely in my control so i can add or modify any entries/info which conveys to unmarshalling rules to unmarshall on derived class.
Thanks for your Suggestion but the it still not working for me.
Here is what I tried
Option #1 - xsi:type
My xsd looks same as what is explained in the example but still the Xsi:type doesn't come in the resulted xml. Do i need to add any other setting while compiling? Which JaxB version should i use for this?
Option#2 - Substitution Groups
When i added the substitution entry part in my xsd, XSD compilation failed saying duplicate names "Engineering" and "Medical". I guess element name and type Name being same compilation cribs(All engineering, Medical,specialization being same both in type definition and element Name)
I can't modify the generated classes as we are using Model driven Architecture. Only thing that is in hand is xsd. Any modification to the xsd is allowed. Ideally First option should have worked. But can't figure out why it is not working. Let me know if you have some suggestion to narrow down the problem.
There are different ways of representing Java inheritance in XML when using JAXB:
Option #1 - xsi:type
In this representation an attribute is used to indicate the subtype being used to populate this element.
<Student>
<Name>Name1</Name>
<Specialization xsi:type="Engineering">
<percentage>78<percentage>
</Specialization>
</Student>
For a detailed example see:
http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-using-xsitype.htmlhtml
Option #2 - Substitution Groups
Here an element name is used to indicate the subtype. This corresponds to the schema concept of substitution groups and leverages JAXB's #XmlElementRef annotation:
<Student>
<Name>Name1</Name>
<Engineering>
<percentage>78<percentage>
</Engineering>
</Student>
For a detailed example see:
http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-using-substitution.html
Using dom4j DOMDocument to feed validator.validate(DOMSource) fails in java 1.6 (with xsi:noNamespaceSchemaLocation is not allowed to appear in root element), works in 1.5
I'm finding the following problem quite intractable (OK, that's an understatement) - any insights will be appreciated. Currently it seems like the best idea is to drop dom4j in favour of e.g. XOM (http://stackoverflow.com/questions/831865/what-java-xml-library-do-you-recommend-to-replace-dom4j).
I've been validating in memory XML created from dom4j 'new DOMDocument()' - but this will not work with Java 6.
The following call to validate(source) of a dom4j (1.6.1) DOMDocument derived DOMSource works with Java 1.5.x but fails with Java 1.6.x:
public void validate() throws Exception {
SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
schemaFactory.setErrorHandler(null);
Schema schemaXSD = schemaFactory.newSchema(new URL(getSchemaURLString()));
Validator validator = schemaXSD.newValidator();
DOMSource source = new DOMSource(getDocument());
validator.validate(source);
}
getSchemaURLString() is also used to add the xsi:noNamespaceSchemaLocation attribute to the root node, i.e.:
xsi:noNamespaceSchemaLocation="http://localhost:8080/integration/xsd/fqlResponseSchema-2.0.xsd"
The exception follows:
Exception: org.xml.sax.SAXParseException: cvc-complex-type.3.2.2: Attribute 'xsi:noNamespaceSchemaLocation' is not allowed to appear in element 'specialfields'.;
complex-type.3.2.2: Attribute 'xsi:noNamespaceSchemaLocation' is not allowed to appear in element 'specialfields'.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:195)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:131)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:384)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:318)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator$XSIErrorReporter.reportError(XMLSchemaValidator.java:417)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.reportSchemaError(XMLSchemaValidator.java:3182)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.processAttributes(XMLSchemaValidator.java:2659)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.handleStartElement(XMLSchemaValidator.java:2066)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.startElement(XMLSchemaValidator.java:705)
at com.sun.org.apache.xerces.internal.jaxp.validation.DOMValidatorHelper.beginNode(DOMValidatorHelper.java:273)
at com.sun.org.apache.xerces.internal.jaxp.validation.DOMValidatorHelper.validate(DOMValidatorHelper.java:240)
at com.sun.org.apache.xerces.internal.jaxp.validation.DOMValidatorHelper.validate(DOMValidatorHelper.java:186)
at com.sun.org.apache.xerces.internal.jaxp.validation.ValidatorImpl.validate(ValidatorImpl.java:104)
at javax.xml.validation.Validator.validate(Validator.java:127)
Here's the start of the XML - generated after disabling the call to validator.validate(source):
<?xml version="1.0" encoding="utf-8"?>
<meetings xsi:noNamespaceSchemaLocation="http://localhost:8080/integration/xsd/fqlResponseSchema-2.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
.............
</meetings>
And of the XSD:
<?xml version="1.0" encoding="utf-8" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
<xs:element name="meetings">
<xs:complexType>
<xs:choice>
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="1" ref="summary" />
<xs:element minOccurs="0" maxOccurs="unbounded" ref="meeting" />
</xs:sequence>
<xs:element ref="error" />
</xs:choice>
</xs:complexType>
</xs:element>
<xs:element name="summary">
................
So my root element is being rejected because it contains a xsi:noNamespaceSchemaLocation attribute. And the schema itself does not specify that as a valid attribute of my root element?
At this point it seems to me that I need to give up on dom4j for this task and switch to one of the other solutions, for example as outlined here:
But I'd like to know what I've done wrong at any rate!
Thanks in advance.
I had the same issue, and I found the following documentation at
http://www.ibm.com/developerworks/xml/library/x-javaxmlvalidapi/index.html
Validate against a document-specified schema
Some documents specify the schema they expect to be validated against,
typically using xsi:noNamespaceSchemaLocation and/or
xsi:schemaLocation attributes like this:
<document xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="http://www.example.com/document.xsd">
...
If you create a schema without specifying a URL, file, or source, then
the Java language creates one that looks in the document being
validated to find the schema it should use. For example:
SchemaFactory factory = SchemaFactory.newInstance("http://www.w3.org/2001/XMLSchema");
Schema schema = factory.newSchema();
However, normally this isn't what you want. Usually the document
consumer should choose the schema, not the document producer.
Furthermore, this approach works only for XSD. All other schema
languages require an explicitly specified schema location.
The reason seems to be that non-namespace aware JAXP SAXParser is being created and used (see Link).
And solution for different libs I found at www.edankert.com.
I have a common data schema in XSD that is used by two different applications, A and B, each uses the data differently. I want to document the different business rules per application. Can I do this?
<xs:complexType name="Account">
<xs:annotation app="A">
<xs:documentation>
The Account entity must be used this way for app A
</xs:documentation>
</xs:annotation>
<xs:annotation app="B">
<xs:documentation>
The Account entity must be used this way for app B
</xs:documentation>
</xs:annotation>
<xs:complexContent>
...
The appinfo element is used within an annotation element, and specifies information to be used by applications:
<xs:annotation>
<xs:appinfo>Any well-formed XML content here</xs:appinfo>
</xs:annotation>
Since any XML content is valid, you can create your own app-specific metadata and put it in the appinfo element.
Apparently not, since the XML Schema specification states that annotations, when they are used, must appear at the beginning of an element's content. However, the annotation element can have as many documentation (or appinfo) elements as you wish. You can distinguish these elements using attributes. You can also have multiple children (of any type) within a documentation element.
So, one way of writing your schema might look like this:
<xs:complexType name="Account">
<xs:annotation >
<xs:documentation app="A">
The Account entity must be used this way for app A
</xs:documentation>
<xs:documentation app="B">
The Account entity must be used this way for app B
</xs:documentation>
</xs:annotation>
<xs:complexContent>
...