Validation Module

From BaseX Documentation
Jump to navigation Jump to search

This XQuery Module contains functions to perform validations against DTDs, XML Schema and RelaxNG. The documentation further describes how to use Schematron validation with BaseX.

Conventions[edit]

All functions and errors in this module are assigned to the http://basex.org/modules/validate namespace, which is statically bound to the validate prefix.

DTD Validation[edit]

Checks whether an XML document validates against a DTD. The input document can be specified as:

  • xs:string, representing a URI (relative URIs will always be resolved against the static base URI of the query),
  • xs:string, representing the resource in its string representation, or
  • node(), representing the resource itself.

If no DTD is supplied in a function, the XML document is expected to contain an embedded DTD doctype declaration.

validate:dtd[edit]

Signatures validate:dtd($input as item()) as empty-sequence()
validate:dtd($input as item(), $schema as xs:string?) as empty-sequence()
Summary Validates the XML $input document against a $schema and returns an empty sequence or an error.
Errors error: the validation fails.
init: the validation process cannot be started.
not-found: no DTD validator is available.
Examples
  • validate:dtd('doc.xml', 'doc.dtd') validates the document doc.xml against the specified DTD file doc.dtd.
  • The following example validates an invalid document against a DTD, which is specified as string:
try {
  let $doc := <invalid/>
  let $schema := '<!ELEMENT root (#PCDATA)>'
  return validate:dtd($doc, $schema)
} catch validate:error {
  'DTD Validation failed.'
}

validate:dtd-info[edit]

Signatures validate:dtd-info($input as item()) as xs:string*
validate:dtd-info($input as item(), $schema as xs:string?) as xs:string*
Summary Validates the XML $input document against a $schema and returns warnings, errors and fatal errors in a string sequence.
Errors init: the validation process cannot be started.
not-found: no DTD validator is available.
Examples
  • validate:dtd-info(<invalid/>, '<!ELEMENT root (#PCDATA)>') returns:
    2:11: Element type "invalid" must be declared..

validate:dtd-report[edit]

width='100%'
Signatures validate:dtd-report($input as item()) as element(report)
validate:dtd-report($input as item(), $schema as xs:string?) as element(report)
Summary Validates the XML $input document against a $schema and returns warnings, errors and fatal errors as XML.
Errors init: the validation process cannot be started.
not-found: no DTD validator is available.
Examples
  • validate:dtd-report(<invalid/>, '<!ELEMENT root (#PCDATA)>') returns:
<report>
  <status>invalid</status>
  <message level="Error" line="2" column="11">Element type "invalid" must be declared.</message>
</report>

XML Schema Validation[edit]

Checks whether an XML document validates against an XML Schema. The input document and the schema can be specified as:

  • xs:string, containing the path to the resource,
  • xs:string, containing the resource in its string representation, or
  • node(), containing the resource itself.

If no schema is given, the input is expected to contain an xsi:(noNamespace)schemaLocation attribute, as defined in W3C XML Schema.

Different XML Schema processors are supported:

  • By default, the Java implementation of XML Schema 1.0 is used (it is based on an old version of Apache Xerces).
  • The latest version of Xerces2 provides implementations of XML Schema 1.0 and 1.1. The processor will be applied if you download one of the binary distributions and copy the following libraries to the lib/custom directory of the full distribution of BaseX:
    • org.eclipse.wst.xml.xpath2.processor_1.2.0.jar
    • cupv10k-runtime.jar
    • xercesImpl.jar
    • xml-apis.jar
  • Saxon Enterprise Edition will be used if you download the ZIP release and if you copy saxon9ee.jar and a valid license key to the classpath.

validate:xsd[edit]

Signatures validate:xsd($input as item()) as empty-sequence()
validate:xsd($input as item(), $schema as item()?) as empty-sequence()
validate:xsd($input as item(), $schema as item()?, $features as map(*)) as empty-sequence()
Summary Validates the XML $input document against a $schema, using the processor-specific $features.
Errors error: the validation fails.
init: the validation process cannot be started.
not-found: no XML Schema validator is available.
Examples
  • Pass on document and schema as nodes:
let $doc := <simple:root xmlns:simple='http://basex.org/simple'/>
let $schema :=
  <xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' targetNamespace='http://basex.org/simple'>
    <xs:element name='root'/>
  </xs:schema>
return validate:xsd($doc, $schema)
  • Validate all documents of a database against the specified schema, using the supplied feature:
for $city in db:open('cities')
return validate:xsd($city, 'city.xsd',
  map { 'http://javax.xml.XMLConstants/feature/secure-processing': true() }
)

validate:xsd-info[edit]

Signatures validate:xsd-info($input as item()) as xs:string*
validate:xsd-info($input as item(), $schema as item()?) as xs:string*
validate:xsd-info($input as item(), $schema as item()?, $features as map(*)) as xs:string*
Summary Validates the XML $input document against a $schema, using the processor-specific $features, and returns warnings, errors and fatal errors in a string sequence.
Errors init: the validation process cannot be started.
not-found: no XML Schema validator is available.

validate:xsd-report[edit]

Signatures validate:xsd-report($input as item()) as element(report)
validate:xsd-report($input as item(), $schema as xs:string?) as element(report)
validate:xsd-report($input as item(), $schema as xs:string?, $features as map(*)) as element(report)
Summary Validates the XML $input document against a $schema, using the processor-specific $features, and returns warnings, errors and fatal errors as XML.
Errors init: the validation process cannot be started.
not-found: no XML Schema validator is available.

validate:xsd-processor[edit]

Signatures validate:xsd-processor() as xs:string
Summary Returns the name of the applied XSD processor.

validate:xsd-version[edit]

Signatures validate:xsd-version() as xs:string
Summary Returns the supported version of XSD Schema.

RelaxNG Validation[edit]

Checks whether an XML document validates against a RelaxNG schema. The input document and the schema can be specified as:

  • xs:string, containing the path to the resource,
  • xs:string, containing the resource in its string representation, or
  • node(), containing the resource itself.

RelaxNG validation will be available if Jing exists in the classpath. The latest version, jing-20091111.jar, is included in the full distributions of BaseX. As Jing additionally supports NVDL validation, you can also use the functions to validate the input against NVDL schemas.

validate:rng[edit]

Signatures validate:rng($input as item(), $schema as item()) as empty-sequence()
validate:rng($input as item(), $schema as item(), $compact as xs:boolean) as empty-sequence()
Summary Validates the XML $input document against a $schema, using the XML or $compact notation.
Errors error: the validation fails.
init: the validation process cannot be started.
not-found: the RelaxNG validator is not available.
Examples
  • validate:rng('doc.xml', 'doc.rng') validates the document doc.xml against the specified schema doc.rng.

validate:rng-info[edit]

Signatures validate:rng-info($input as item(), $schema as item()) as xs:string*
validate:rng-info($input as item(), $schema as item(), $compact as xs:boolean) as xs:string*
Summary Validates the XML $input document against a $schema, using the XML or $compact notation, and returns warnings, errors and fatal errors in a string sequence.
Errors init: the validation process cannot be started.
not-found: the RelaxNG validator is not available.

validate:rng-report[edit]

Signatures validate:rng-report($input as item(), $schema as xs:string) as element(report)
validate:rng-report($input as item(), $schema as xs:string, $compact as xs:boolean) as element(report)
Summary Validates the XML $input document against a $schema, using the XML or $compact notation, and returns warnings, errors and fatal errors as XML.
Errors init: the validation process cannot be started.
not-found: The RelaxNG validator is not available.

Schematron Validation[edit]

If you want to use Schematron for validating documents, simply install Vincent Lizzi’s excellent Schematron XQuery Module for BaseX:

repo:install('https://github.com/Schematron/schematron-basex/raw/master/dist/schematron-basex-1.2.xar')

The following query illustrates how documents are validated. It is directly taken from the GitHub project:

import module namespace schematron = "http://github.com/Schematron/schematron-basex";

let $sch := schematron:compile(doc('rules.sch'))
let $svrl := schematron:validate(doc('document.xml'), $sch)
return (
  schematron:is-valid($svrl),
  for $message in schematron:messages($svrl)
  return concat(schematron:message-level($message), ': ', schematron:message-description($message))
)

Errors[edit]

Code Description
error The document cannot be validated against the specified schema.
init The validation cannot be started.
not-found No validator is available.

Changelog[edit]

Version 9.2
Version 9.0
  • Updated: error codes updated; errors now use the module namespace
Version 8.5
  • Updated: Relative URIs will always be resolved against the static base URI of the query
Version 8.3
Version 7.6

The module was introduced with Version 7.3.