===============
Validation
===============

.. contents::
    :local:
    :depth: 2

Validators
=======

DOMDocumentValidationStack
--------------------------

``Kitodo\Dlf\Validation\DOMDocumentValidationStack`` implementation of ``Kitodo\Dlf\Validation\AbstractDlfValidationStack`` for validating DOMDocument against the configurable validators.

The configuration is an array validator configurations each with following entries:

.. t3-field-list-table::
   :header-rows: 1

   - :field:                    Key
     :description:              Description

   - :field:                    title
     :description:              Title of the validator

   - :field:                    className
     :description:              Fully qualified class name of validator class derived from ``Kitodo\Dlf\Validation\AbstractDlfValidator``

   - :field:                    breakOnError
     :description:              Indicates whether the validation of the validation stack should be interrupted in case of errors.

   - :field:                    configuration
     :description:              Specific configuration of validator


XmlSchemesValidator
--------------------------

``Kitodo\Dlf\Validation\XmlSchemesValidator`` combines the configured schemes into one schema and validates the provided DOMDocument against this.

The configuration is an array validator configurations each with following entries:

.. t3-field-list-table::
   :header-rows: 1

   - :field:                    Key
     :description:              Description

   - :field:                    namespace
     :description:              Specifies the URI of the namespace to import

   - :field:                    schemaLocation
     :description:              Specifies the URI to the schema for the imported namespace


SaxonXslToSvrlValidator
--------------------------

``Kitodo\Dlf\Validation\SaxonXslToSvrlValidator`` validates the DOMDocument against an XSL Schematron and converts error output to validation errors.

To use the validator, the XSL Schematron must be available alongside the XSL processor as a JAR file, and the required Java version of the processor must be installed.

.. t3-field-list-table::
   :header-rows: 1

   - :field:                    Key
     :description:              Description

   - :field:                    jar
     :description:              Absolute path to the Saxon JAR file

   - :field:                    xsl
     :description:              Absolute path to the XSL Schematron

DOMDocumentValidation Middleware
=======

``Kitodo\Dlf\Validation\DOMDocumentValidation`` middleware can be used via the parameter ``middleware`` with the value ``dlf/domDocumentValidation`` and the parameter ``url`` with the URL to the ``DOMDocument`` content to validate.

Configuration
--------------------------

The validation middleware can be configured through the plugin settings in TypoScript with the block called ``domDocumentValidationValidators``.

   .. code-block::

      plugin.tx_dlf {
          settings {
              domDocumentValidationValidators {
                  validator {
                     ...
                  },
                  validatorStack {
                     ...
                  },
                  ...

Validators derived from ``Kitodo\Dlf\Validation\AbstractDlfValidator`` can be configured here. This also includes the use of validation stack implementations derived from ``Kitodo\Dlf\Validation\AbstractDlfValidationStack``, which use ``DOMDocument`` as the ``valueClassName`` for validation. This allows for multiple levels of nesting.

In the background of the middleware, the ``Kitodo\Dlf\Validation\DOMDocumentValidationStack`` is used, to which the configured validators are assigned.

TypoScript Example
^^^^^^^^^^^^^^^^^^^^^^^^^

   .. code-block::

      plugin.tx_dlf {
          settings {
              storagePid = {$config.storagePid}
              domDocumentValidationValidators {
                 10 {
                     title = XML-Schemes Validator
                     className = Kitodo\Dlf\Validation\XmlSchemesValidator
                     breakOnError = false
                     configuration {
                         oai {
                             namespace = http://www.openarchives.org/OAI/2.0/
                             schemaLocation = https://www.openarchives.org/OAI/2.0/OAI-PMH.xsd
                         }
                         mets {
                             namespace = http://www.loc.gov/METS/
                             schemaLocation = http://www.loc.gov/standards/mets/mets.xsd
                         }
                         mods {
                             namespace = http://www.loc.gov/mods/v3
                             schemaLocation = http://www.loc.gov/standards/mods/mods.xsd
                         }
                     }
                 },
                 ...