API for ISO Schematron Skeleton

Rick Jelliffe, 2018/01/9 from 2010/04/14

 

This document provides documentation on the XSLT API available in the implementation of Schematron called iso_schematron_skeleton.xsl. (available in an XSLT1 and XSLT2 version). The API makes available as much information from the schema.

The skeleton is an XSLT script which provides all the basic parsing and validating routines for compiling a Schematron schema into XSLT. Schematron was designed to allow many different uses, and the skeleton gives you a headstart in creating a customized implementation. You just need to write XSLT templates to override the
default ones. (The program you write is sometimes called a meta-stylesheet.) It is the meta-stylesheet that is called as the XSLT script, not the skeleton. There are several pre-processing stages which the Schematron schema should be processed through first, to handle such things as include statements and abstract patterns.

Phases and error reporting for problems in the schema itself are handled by the skeleton with no interaction with a “meta-stylesheet”. Note that there is no guarantee that the context node is always the element being handled: in most cases the only information available is the information in the parameters.

For an introductory tutorial on using this API, see Bob DuCharme’s Schematron 1.5: Looking Under the Hood

History:

This is an updated version of the API for the Schematron 1.5 implementation called skeleton1-5.xsl, which in turn comes from the new architecture contributed by Oliver Becker for Schematron 1.3.)

The current API contains only additions. Well-written meta-stylesheets that use the new API will be be able to run on the existing 1.5 and 1.6 skeletons. Similarly, it should be possible to upgrade the skeleton from 1.5 or 1.6 to the iso-schematron-skeleton only by correcting the import statement at the beginning of the meta-stylsheet. Additions or re-groupings from the 1.5 schema are shown in red. Deletions have overstrike. Additions to support the ISO Schematron 2016 properties feature are shown in green.


process-prolog

The process-prolog template gets called at the start of the validation session. It has no parameters. The default implementation is no action.


process-root

The process-root template processes the root element of the schema (which is not the same thing as the root of the document / and need not be the document element /*) .

node-list $contents
string $schemaVersion
The version of the schema, perhaps a datestamp.
"xslt" | "xpath" | "xslt2" | ... $queryBinding
The query language binding.
string $title
The title of this schema
"iso" | "1.5" | "1.6" | ... $version
The version of Schematron being used.

Rich properties:

XML SystemId  $icon
The URI of an icon
XML ID  $id
The unique identifier with the schema for the schema element.
SGML FPI  $fpi
The Formal Public Identifier for this schema.
IETF languag  $lang
The human language used in this schema, from
xml:lang
URL  $see
Link to documentation on WWW or file
"preserve" | "default"  $space
The value for xml:space

To print the documentation paragraphs, use <xsl:apply-templates mode="do-schema-p" />

To output the results, use <xsl:copy-of select="$contents" />


process-assert

The process-assert template handles asserts whose test has failed.

XPath $test
The test
XML IDREFS $diagnostics
A list of the idrefs diagnostic elements related to the current assertion
XML IDREFS $properties
A list of the idrefs property elements related to the current assertion
XML NMTOKEN  $flag
The name of a flag that becomes true because this assertion fails. The flag is true for the document if it is flagged true on any assertion. .

Rich properties:

XML SystemId  $icon
The URI of an icon
XML ID  $id
The unique identifier with the schema for the assert element.
SGML FPI  $fpi
The Formal Public Identifier for this  assertion.
IETF language  $lang
The human language used in this assertion,
from xml:lang
URL  $see
Link to documentation on WWW or file
"preserve" | "default"  $space
The value for xml:space

Linking properties:

XML NMTOKEN  $role
A name for the generic role of this assertion.
The schema creator would have their own vocabulary.
XPath  $subject
A path relative to the current context to some
interesting node considered the subject.

To print the text contents, use <xsl:apply-templates mode="text" />


process-diagnostic

The process-diagnostic template handles diagnostic messages for assert statements that have failed and report statements that have succeeded. The diagnostics are evaluated in the context of the rule.

Rich properties:

XML SystemId  $icon
The URI of an icon
XML ID  $id
The unique identifier with the schema for the
assert
element.
SGML FPI  $fpi
The Formal Public Identifier for this
assertion.
IETF language  $lang
The human language used in this assertion,
from xml:lang
URL  $see
Link to documentation on WWW or file
"preserve" | "default"  $space
The value for xml:space

process-dir

The process-dir template handles bi-directionality markup, which is only needed by certain human scripts such as Arabic.

"ltr" or "rtl" or ""  $value
Left-to-right or right-to-left or unspecified

process-emph

The process-emph template handles the markup of emphasized text in paragraphs, assertions and diagnostics. It has no parameters.


process-message

The process-message handles default outputing of text.

string $pattern
Some text that may be some kind of pattern
string $role
Some text that may be some kind of role

process-name

The process-name templates handle name strings that can be used in assertions. asssert and report only provide name subelements rather than the more general value-of elements to encourage plain language and generic descriptions rather than specific diagnostics, for which purpose the diagnostics elements are used.

string $name
The name of the current element, or of the node specified by a name element

process-ns

The process-ns template reports on ns declarations, which are used to transmit on namespace information by the skeleton.

Namespace NCName $prefix
The prefix of a namespace
XML SystemId $uri
The (internationalized) URI Reference of a namespace

process-p

The process-p template handles paragraphs.

XML NMTOKEN $class
An attribute that can be used for stylesheet style
XML ID $id
The unique identifier with the schema for the p element.
XML SystemId $icon
The URI of an icon
IETF Language $lang
The human language used in this paragraph

To print the text contents, use <xsl:apply-templates mode="text" />


process-pattern

The process-pattern reports on the start of evaluation of a pattern element.

string $name
The title of the current pattern
XML NCNAMES $is-a
Empty or not provided if the pattern is not derived from an abstract pattern. Otherwise the name of the abstract pattern. A list may be used if there was a sequence of abstract patterns.

Rich properties:

XML SystemId  $icon
The URI of an icon
XML ID $id
The unique identifier with the schema for the pattern element.
SGML FPI $fpi
The Formal Public Identifier for this pattern.
IETF language $lang
The human language used in this pattern, from xml:lang
URL $see
A (internationalized) URI reference to some supporting or defining documentation
"preserve" | "default" $space
The value for xml:space

To print the documentation contents, use <xsl:apply-templates
mode="do-pattern-p"/>


process-property

The process-property template handles property element.  A property is a a dynamic element that is similar to diagnostics: the property provides more information to downstream computer processing, while the diagnostics provides more information for humans to understand and resolve the issue.   Both thereby allow the assertion text to be cleared of information that does not relate to the positive expression in natural language of the assertion.

XML ID $name
The ID of the property

string $name

The name of the property’s simple value
string $value
The simple value of the property
node-list $contents
The contents of the property

process-report

The process-report template handles report whose test has succeeded.

XPath $test
The test
XML IDREFS $diagnostics
A list of the idrefs diagnostic elements related to the current assertion
XML IDREFS $properties
A list of the idrefs diagnostic elements related to the current assertion
XML NMTOKEN  $flag
The name of a flag that becomes true because this assertion fails. The flag is true for the document if it is flagged true on any assertion.

Rich properties:

XML SystemId $icon
The URI of an icon
XML ID $id
The unique identifier with the schema for the report element.
SGML FPI $fpi
The Formal Public Identifier for this report.
IETF language $lang
The human language used in this report, from xml:lang
URL  $see
Link to documentation on WWW or file
"preserve" | "default"  $space
The value for xml:space

Linking properties:

XML NMTOKEN  $role
A name for the generic role of this assertion. The schema creator would have their own vocabulary.
XPath $subject
A path relative to the current context to some interesting node considered the subject.

To print the text contents, use <xsl:apply-templates mode="text" />


process-rule

The process-rule reports that a rule element has fired: its context attribute matched some nodes. .

XSLT expression $context
The expression that gives the context of the current
XML IDREFS $properties
A list of the idrefs property elements related to the current rule

Rich properties:

XML SystemId  $icon
The URI of an icon
XML ID  $id
The unique identifier with the schema for this rule element.
SGML FPI  $fpi
The Formal Public Identifier for this rule. 
IETF language $lang
The human language used in this rule, from xml:lang
URL $see
Link to documentation on WWW or file
"preserve" | "default" $space
The value for xml:space

Linking properties:

XML NMTOKEN $role
A name for the generic role of this assertion. The schema creator would have their own vocabulary.
XPath $subject
A path relative to the current context to some interesting node considered the subject.

process-span

The process-span handles span elements, which are generic elements for styling, like HTML’s .

XML NMTOKEN $class
An attribute that can be used for stylesheet style

process-title

The process-title handles title elements, which are generic elements for styling, like HTML’s .

XML NMTOKEN $class
An attribute that can be used for stylesheet style

By default, titles are handled by invocing process-p with the parameter class with a value “title”.


process-value-of

The process-value-of template handles value-of elements, which are used in diagnostic messages to allow very specific hinting .

XPath $select
The path of some node that will be evaluated and printed.

Global Parameters

There are several global parameters that may be available for use. However, it is not a requirement to follow these, and implementations may not supply them with any value. So a test of string-length(variable) < 0 is appropriate in each case.

 

Parameter

Value

Description

allow-foreign “true” | “false” (default) Pass non-Schematron elements to the generated
stylesheet. Pass the Schematron elements span, emph and dir: to
the output SVRL.
fileNameParameter string A parameter passed to the Validator and
potentially available as a variable in Schematron schemas as
$fileNameParameter
fileDirParameter string A parameter passed to the Validator and
potentially available as a variable in Schematron schemas as
$fileDirParameter
archiveNamePaameter string A parameter passed to the Validator and
potentially available as a variable in Schematron schemas as
$archiveNameParameter
archiveDirParameter string A parameter passed to the Validator and
potentially available as a variable in Schematron schemas as
$archivePathParameter
debug true” | “false” (default) Verbose error messages (Note this may be
superceded by “verbose” at some stage in the future.)
generate-paths true|false generate the SVRL @location attribute with XPaths
diagnose yes | no Add the diagnostics to the assertion results
terminate yes | no | true | false | assert Terminate on the first failed assertion or
successful report
message-newline “true” (default) | “false” Generate an extra newline at the end of messages
output-encoding string The encoding used for output, for example if the
output is XML