source: trunk/src/xmlpatterns/schema/qxsdparticlechecker.cpp@ 973

/****************************************************************************
**
** Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at [email protected].
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qxsdparticlechecker_p.h"

#include "qxsdelement_p.h"
#include "qxsdmodelgroup_p.h"
#include "qxsdschemahelper_p.h"
#include "qxsdstatemachine_p.h"
#include "qxsdstatemachinebuilder_p.h"
#include "qxsdtypechecker_p.h"

#include <QtCore/QFile>

QT_BEGIN_NAMESPACE

using namespace QPatternist;

namespace QPatternist
{
    /**
     * This template specialization is picked up by XsdStateMachine and allows us
     * to print nice edge labels.
     */
    template <>
    QString XsdStateMachine<XsdTerm::Ptr>::transitionTypeToString(XsdTerm::Ptr term) const
    {
        if (!term)
            return QLatin1String("(empty)");

        if (term->isElement()) {
            return XsdElement::Ptr(term)->displayName(m_namePool);
        } else if (term->isWildcard()) {
            const XsdWildcard::Ptr wildcard(term);
            return QLatin1String("(wildcard)");
        } else {
            return QString();
        }
    }
}

/**
 * This method is used by the isUPAConform method to check whether @p term and @p otherTerm
 * are the same resp. match each other.
 */
static bool termMatches(const XsdTerm::Ptr &term, const XsdTerm::Ptr &otherTerm, const NamePool::Ptr &namePool)
{
    if (term->isElement()) {
        const XsdElement::Ptr element(term);

        if (otherTerm->isElement()) {
            // both, the term and the other term are elements

            const XsdElement::Ptr otherElement(otherTerm);

            // if they have the same name they match
            if (element->name(namePool) == otherElement->name(namePool))
                return true;

        } else if (otherTerm->isWildcard()) {
            // the term is an element and the other term a wildcard

            const XsdWildcard::Ptr wildcard(otherTerm);

            // wildcards using XsdWildcard::absentNamespace, so we have to fix that here
            QXmlName name = element->name(namePool);
            if (name.namespaceURI() == StandardNamespaces::empty)
                name.setNamespaceURI(namePool->allocateNamespace(XsdWildcard::absentNamespace()));

            // if the wildcards namespace constraint allows the elements name, they match
            if (XsdSchemaHelper::wildcardAllowsExpandedName(name, wildcard, namePool))
                return true;
        }
    } else if (term->isWildcard()) {
        const XsdWildcard::Ptr wildcard(term);

        if (otherTerm->isElement()) {
            // the term is a wildcard and the other term an element

            const XsdElement::Ptr otherElement(otherTerm);

            // wildcards using XsdWildcard::absentNamespace, so we have to fix that here
            QXmlName name = otherElement->name(namePool);
            if (name.namespaceURI() == StandardNamespaces::empty)
                name.setNamespaceURI(namePool->allocateNamespace(XsdWildcard::absentNamespace()));

            // if the wildcards namespace constraint allows the elements name, they match
            if (XsdSchemaHelper::wildcardAllowsExpandedName(name, wildcard, namePool))
                return true;

        } else if (otherTerm->isWildcard()) {
            // both, the term and the other term are wildcards

            const XsdWildcard::Ptr otherWildcard(otherTerm);

            // check if the range of the wildcard overlaps.
            const XsdWildcard::Ptr intersectionWildcard = XsdSchemaHelper::wildcardIntersection(wildcard, otherWildcard);
            if (!intersectionWildcard ||
                (intersectionWildcard && !(intersectionWildcard->namespaceConstraint()->variety() != XsdWildcard::NamespaceConstraint::Not && intersectionWildcard->namespaceConstraint()->namespaces().isEmpty())))
                return true;
        }
    }

    return false;
}

/**
 * This method is used by the subsumes algorithm to check whether the @p derivedTerm is validly derived from the @p baseTerm.
 *
 * @param baseTerm The term of the base component (type or group).
 * @param derivedTerm The term of the derived component (type or group).
 * @param particles A hash to map the passed base and derived term to the particles they belong to.
 * @param context The schema context.
 * @param errorMsg The error message in the case that an error occurs.
 */
static bool derivedTermValid(const XsdTerm::Ptr &baseTerm, const XsdTerm::Ptr &derivedTerm, const QHash<XsdTerm::Ptr, XsdParticle::Ptr> &particles, const XsdSchemaContext::Ptr &context, QString &errorMsg)
{
    const NamePool::Ptr namePool(context->namePool());

    // find the particles where the base and derived term belongs to
    const XsdParticle::Ptr baseParticle = particles.value(baseTerm);
    const XsdParticle::Ptr derivedParticle = particles.value(derivedTerm);

    // check that an empty particle can not be derived from a non-empty particle
    if (derivedParticle && baseParticle) {
        if (XsdSchemaHelper::isParticleEmptiable(derivedParticle) && !XsdSchemaHelper::isParticleEmptiable(baseParticle)) {
            errorMsg = QtXmlPatterns::tr("Empty particle cannot be derived from non-empty particle.");
            return false;
        }
    }

    if (baseTerm->isElement()) {
        const XsdElement::Ptr element(baseTerm);

        if (derivedTerm->isElement()) {
            // if both terms are elements

            const XsdElement::Ptr derivedElement(derivedTerm);

            // check names are equal
            if (element->name(namePool) != derivedElement->name(namePool)) {
                errorMsg = QtXmlPatterns::tr("Derived particle is missing element %1.").arg(formatKeyword(element->displayName(namePool)));
                return false;
            }

            // check value constraints are equal (if available)
            if (element->valueConstraint() && element->valueConstraint()->variety() == XsdElement::ValueConstraint::Fixed) {
                if (!derivedElement->valueConstraint()) {
                    errorMsg = QtXmlPatterns::tr("Derived element %1 is missing value constraint as defined in base particle.").arg(formatKeyword(derivedElement->displayName(namePool)));
                    return false;
                }

                if (derivedElement->valueConstraint()->variety() != XsdElement::ValueConstraint::Fixed) {
                    errorMsg = QtXmlPatterns::tr("Derived element %1 has weaker value constraint than base particle.").arg(formatKeyword(derivedElement->displayName(namePool)));
                    return false;
                }

                const QSourceLocation dummyLocation(QUrl(QLatin1String("http://dummy.org")), 1, 1);
                const XsdTypeChecker checker(context, QVector<QXmlName>(), dummyLocation);
                if (!checker.valuesAreEqual(element->valueConstraint()->value(), derivedElement->valueConstraint()->value(), derivedElement->type())) {
                    errorMsg = QtXmlPatterns::tr("Fixed value constraint of element %1 differs from value constraint in base particle.").arg(formatKeyword(derivedElement->displayName(namePool)));
                    return false;
                }
            }

            // check that a derived element can not be nillable if the base element is not nillable
            if (!element->isNillable() && derivedElement->isNillable()) {
                errorMsg = QtXmlPatterns::tr("Derived element %1 cannot be nillable as base element is not nillable.").arg(formatKeyword(derivedElement->displayName(namePool)));
                return false;
            }

            // check that the constraints of the derived element are more strict then the constraints of the base element
            const XsdElement::BlockingConstraints baseConstraints = element->disallowedSubstitutions();
            const XsdElement::BlockingConstraints derivedConstraints = derivedElement->disallowedSubstitutions();
            if (((baseConstraints & XsdElement::RestrictionConstraint) && !(derivedConstraints & XsdElement::RestrictionConstraint)) ||
                ((baseConstraints & XsdElement::ExtensionConstraint) && !(derivedConstraints & XsdElement::ExtensionConstraint)) ||
                ((baseConstraints & XsdElement::SubstitutionConstraint) && !(derivedConstraints & XsdElement::SubstitutionConstraint))) {
                errorMsg = QtXmlPatterns::tr("Block constraints of derived element %1 must not be more weaker than in the base element.").arg(formatKeyword(derivedElement->displayName(namePool)));
                return false;
            }

            // if the type of both elements is the same we can stop testing here
            if (element->type()->name(namePool) == derivedElement->type()->name(namePool))
                return true;

            // check that the type of the derived element can validly derived from the type of the base element
            if (derivedElement->type()->isSimpleType()) {
                if (!XsdSchemaHelper::isSimpleDerivationOk(derivedElement->type(), element->type(), SchemaType::DerivationConstraints())) {
                    errorMsg = QtXmlPatterns::tr("Simple type of derived element %1 cannot be validly derived from base element.").arg(formatKeyword(derivedElement->displayName(namePool)));
                    return false;
                }
            } else if (derivedElement->type()->isComplexType()) {
                if (!XsdSchemaHelper::isComplexDerivationOk(derivedElement->type(), element->type(), SchemaType::DerivationConstraints())) {
                    errorMsg = QtXmlPatterns::tr("Complex type of derived element %1 cannot be validly derived from base element.").arg(formatKeyword(derivedElement->displayName(namePool)));
                    return false;
                }
            }

            // if both, derived and base element, have a complex type that contains a particle itself, apply the subsumes algorithm
            // recursive on their particles
            if (element->type()->isComplexType() && derivedElement->type()->isComplexType()) {
                if (element->type()->isDefinedBySchema() && derivedElement->type()->isDefinedBySchema()) {
                    const XsdComplexType::Ptr baseType(element->type());
                    const XsdComplexType::Ptr derivedType(derivedElement->type());
                    if ((baseType->contentType()->variety() == XsdComplexType::ContentType::ElementOnly ||
                        baseType->contentType()->variety() == XsdComplexType::ContentType::Mixed) &&
                        (derivedType->contentType()->variety() == XsdComplexType::ContentType::ElementOnly ||
                         derivedType->contentType()->variety() == XsdComplexType::ContentType::Mixed)) {

                        return XsdParticleChecker::subsumes(baseType->contentType()->particle(), derivedType->contentType()->particle(), context, errorMsg);
                    }
                }
            }

            return true;
        } else if (derivedTerm->isWildcard()) {
            // derive a wildcard from an element is not allowed
            errorMsg = QtXmlPatterns::tr("Element %1 is missing in derived particle.").arg(formatKeyword(element->displayName(namePool)));
            return false;
        }
    } else if (baseTerm->isWildcard()) {
        const XsdWildcard::Ptr wildcard(baseTerm);

        if (derivedTerm->isElement()) {
            // the base term is a wildcard and derived term an element

            const XsdElement::Ptr derivedElement(derivedTerm);

            // wildcards using XsdWildcard::absentNamespace, so we have to fix that here
            QXmlName name = derivedElement->name(namePool);
            if (name.namespaceURI() == StandardNamespaces::empty)
                name.setNamespaceURI(namePool->allocateNamespace(XsdWildcard::absentNamespace()));

            // check that name of the element is allowed by the wildcards namespace constraint
            if (!XsdSchemaHelper::wildcardAllowsExpandedName(name, wildcard, namePool)) {
                errorMsg = QtXmlPatterns::tr("Element %1 does not match namespace constraint of wildcard in base particle.").arg(formatKeyword(derivedElement->displayName(namePool)));
                return false;