Xalan-C++ API Documentation

The Xalan C++ XSLT Processor Version 1.9

XPathExecutionContext.hpp

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/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#if !defined(XPATHEXECUTIONCONTEXT_HEADER_GUARD_1357924680)
#define XPATHEXECUTIONCONTEXT_HEADER_GUARD_1357924680



// Base include file.  Must be first.
#include <xalanc/XPath/XPathDefinitions.hpp>



#include <cassert>



#include <xalanc/Include/XalanVector.hpp>



#include <xalanc/XalanDOM/XalanDOMString.hpp>



// Base class header file...
#include <xalanc/PlatformSupport/ExecutionContext.hpp>



#include <xalanc/XPath/MutableNodeRefList.hpp>



XALAN_CPP_NAMESPACE_BEGIN



class XalanDecimalFormatSymbols;
class PrefixResolver;
class XalanQName;
class XObject;
class XObjectPtr;
class XObjectFactory;
class XalanDocument;
class XalanElement;
class XalanNode;
class XalanText;



//
// An abstract class which provides support for executing XPath functions
// and extension functions.
//

class XALAN_XPATH_EXPORT XPathExecutionContext : public ExecutionContext
{
public:

    typedef XalanVector<XObjectPtr>         XObjectArgVectorType;

    typedef NodeRefListBase::size_type  size_type;

    explicit
    XPathExecutionContext(MemoryManagerType& m_memoryManager, XObjectFactory*   theXObjectFactory = 0);

    virtual
    ~XPathExecutionContext();

    virtual void
    reset() = 0;

    virtual XalanNode*
    getCurrentNode() const = 0;

    virtual void
    pushCurrentNode(XalanNode*  theCurrentNode) = 0;

    virtual void
    popCurrentNode() = 0;

    class CurrentNodePushAndPop
    {
    public:

        CurrentNodePushAndPop(
                XPathExecutionContext&  theExecutionContext,
                XalanNode*              theNewNode) :
            m_executionContext(theExecutionContext)
        {
            theExecutionContext.pushCurrentNode(theNewNode);
        }

        ~CurrentNodePushAndPop()
        {
            m_executionContext.popCurrentNode();
        }

    private:

        XPathExecutionContext&  m_executionContext;
    };

    XObjectFactory&
    getXObjectFactory() const
    {
        assert(m_xobjectFactory != 0);

        return *m_xobjectFactory;
    }

    virtual bool
    isNodeAfter(
            const XalanNode&    node1,
            const XalanNode&    node2) const = 0;

    virtual void
    pushContextNodeList(const NodeRefListBase&  theList) = 0;

    virtual void    
    popContextNodeList() = 0;

    class ContextNodeListPushAndPop
    {
    public:

        ContextNodeListPushAndPop(
                XPathExecutionContext&      theExecutionContext,
                const NodeRefListBase&      theNodeList) :
            m_executionContext(theExecutionContext)
        {
            m_executionContext.pushContextNodeList(theNodeList);
        }

        ~ContextNodeListPushAndPop()
        {
            m_executionContext.popContextNodeList();
        }

    private:

        XPathExecutionContext&  m_executionContext;
    };

    virtual const NodeRefListBase&
    getContextNodeList() const = 0;

    /*
     * Get the count of nodes in the current context node list.
     *
     * @return length of list
     */
    virtual size_type
    getContextNodeListLength() const = 0;

    /*
     * Get the position of the node in the current context node list.
     * Note that this is 1-based indexing (XPath/XSLT-style), not 0-based.
     * Thus, 0 will be returned if the node was not found.
     *
     * @return position in list
     */
    virtual size_type
    getContextNodeListPosition(const XalanNode&     contextNode) const = 0;

    virtual bool
    elementAvailable(const XalanQName&  theQName) const = 0;

    virtual bool
    elementAvailable(
            const XalanDOMString&   theName,
            const LocatorType*      locator) const = 0;

    virtual bool
    functionAvailable(const XalanQName&     theQName) const = 0;

    virtual bool
    functionAvailable(
            const XalanDOMString&   theName,
            const LocatorType*      locator) const = 0;

    virtual const XObjectPtr
    extFunction(
            const XalanDOMString&           theNamespace,
            const XalanDOMString&           functionName,
            XalanNode*                      context,
            const XObjectArgVectorType&     argVec,
            const LocatorType*              locator) = 0;

    virtual XalanDocument*
    parseXML(
            MemoryManagerType&      theManager,
            const XalanDOMString&   urlString,
            const XalanDOMString&   base) const = 0;

    virtual MutableNodeRefList*
    borrowMutableNodeRefList() = 0;

    virtual bool
    returnMutableNodeRefList(MutableNodeRefList*    theList) = 0;

    class BorrowReturnMutableNodeRefList
    {
    public:

        BorrowReturnMutableNodeRefList(XPathExecutionContext&   executionContext) :
            m_xpathExecutionContext(&executionContext),
            m_mutableNodeRefList(executionContext.borrowMutableNodeRefList())
        {
            assert(m_mutableNodeRefList != 0);
        }

        // N.B. Non-const copy constructor semantics (like std::auto_ptr)
        BorrowReturnMutableNodeRefList(const BorrowReturnMutableNodeRefList&    theSource) :
            m_xpathExecutionContext(theSource.m_xpathExecutionContext),
            m_mutableNodeRefList(theSource.m_mutableNodeRefList)
        {
            assert(m_mutableNodeRefList != 0);

            ((BorrowReturnMutableNodeRefList&)theSource).m_mutableNodeRefList = 0;
        }

        ~BorrowReturnMutableNodeRefList()
        {
            release();
        }

        MutableNodeRefList&
        operator*() const
        {
            assert(m_mutableNodeRefList != 0);

            return *m_mutableNodeRefList;
        }

        MutableNodeRefList*
        get() const
        {
            return m_mutableNodeRefList;
        }

        MutableNodeRefList*
        operator->() const
        {
            return get();
        }

        void
        release()
        {
            assert(m_xpathExecutionContext != 0);

            if (m_mutableNodeRefList != 0)
            {
                m_xpathExecutionContext->returnMutableNodeRefList(m_mutableNodeRefList);

                m_mutableNodeRefList = 0;
            }
        }

        BorrowReturnMutableNodeRefList
        clone() const
        {
            assert(m_xpathExecutionContext != 0);

            BorrowReturnMutableNodeRefList  theResult(*m_xpathExecutionContext);

            *theResult = *m_mutableNodeRefList;

            return theResult;
        }

        // N.B. Non-const assignment operator semantics.
        BorrowReturnMutableNodeRefList&
        operator=(BorrowReturnMutableNodeRefList&   theRHS)
        {
            release();

            m_xpathExecutionContext = theRHS.m_xpathExecutionContext;

            m_mutableNodeRefList = theRHS.m_mutableNodeRefList;

            theRHS.m_mutableNodeRefList = 0;

            return *this;
        }

    private:

        XPathExecutionContext*  m_xpathExecutionContext;

        MutableNodeRefList*     m_mutableNodeRefList;
    };

    virtual XalanDOMString&
    getCachedString() = 0;

    virtual bool
    releaseCachedString(XalanDOMString&     theString) = 0;

    class GetAndReleaseCachedString
    {
    public:

        GetAndReleaseCachedString(XPathExecutionContext&    theExecutionContext) :
            m_executionContext(&theExecutionContext),
            m_string(&theExecutionContext.getCachedString())
        {
        }

        // Note non-const copy semantics...
        GetAndReleaseCachedString(GetAndReleaseCachedString&    theSource) :
            m_executionContext(theSource.m_executionContext),
            m_string(theSource.m_string)
        {
            theSource.m_string = 0;
        }

        ~GetAndReleaseCachedString()
        {
            if (m_string != 0)
            {
                m_executionContext->releaseCachedString(*m_string);
            }
        }

        XalanDOMString&
        get() const
        {
            assert(m_string != 0);

            return *m_string;
        }

        XPathExecutionContext&
        getExecutionContext() const
        {
            return *m_executionContext;
        }

    private:

        // Not implemented...
        GetAndReleaseCachedString&
        operator=(const GetAndReleaseCachedString&);


        // Data members...
        XPathExecutionContext*  m_executionContext;

        XalanDOMString*         m_string;
    };

    virtual MutableNodeRefList*
    createMutableNodeRefList(MemoryManagerType& theManager) const = 0;

    virtual void
    getNodeSetByKey(
            XalanDocument*          doc,
            const XalanQName&       qname,
            const XalanDOMString&   ref,
            MutableNodeRefList&     nodelist) = 0;

    virtual void
    getNodeSetByKey(
            XalanDocument*          doc,
            const XalanDOMString&   name,
            const XalanDOMString&   ref,
            const LocatorType*      locator,
            MutableNodeRefList&     nodelist) = 0;

    virtual const XObjectPtr
    getVariable(
            const XalanQName&   name,
            const LocatorType*  locator = 0) = 0;

    virtual const PrefixResolver*
    getPrefixResolver() const = 0;

    virtual void
    setPrefixResolver(const PrefixResolver*     thePrefixResolver) = 0;

    class PrefixResolverSetAndRestore
    {
    public:

        PrefixResolverSetAndRestore(
                XPathExecutionContext&  theExecutionContext,
                const PrefixResolver*   theResolver) :
            m_executionContext(theExecutionContext),
            m_savedResolver(theExecutionContext.getPrefixResolver())
        {
            m_executionContext.setPrefixResolver(theResolver);
        }

        PrefixResolverSetAndRestore(
                XPathExecutionContext&  theExecutionContext,
                const PrefixResolver*   theOldResolver,
                const PrefixResolver*   theNewResolver) :
            m_executionContext(theExecutionContext),
            m_savedResolver(theOldResolver)
        {
            m_executionContext.setPrefixResolver(theNewResolver);
        }

        ~PrefixResolverSetAndRestore()
        {
            m_executionContext.setPrefixResolver(m_savedResolver);
        }

    private:

        XPathExecutionContext&          m_executionContext;
        const PrefixResolver* const     m_savedResolver;
    };

    virtual const XalanDOMString*
    getNamespaceForPrefix(const XalanDOMString&     prefix) const = 0;

    virtual const XalanDOMString&
    findURIFromDoc(const XalanDocument*     owner) const = 0;

    virtual const XalanDOMString&
    getUnparsedEntityURI(
            const XalanDOMString&   theName,
            const XalanDocument&    theDocument) const = 0;

    virtual bool
    shouldStripSourceNode(const XalanText&  node) = 0;

    virtual XalanDocument*
    getSourceDocument(const XalanDOMString&     theURI) const = 0;

    virtual void
    setSourceDocument(
            const XalanDOMString&   theURI,
            XalanDocument*          theDocument) = 0;

    virtual void formatNumber(
            double                              number,
            const XalanDOMString&               pattern,
            XalanDOMString&                     theResult,
            const XalanNode*                    context = 0,
            const LocatorType*                  locator = 0) = 0;

    virtual void formatNumber(
            double                              number,
            const XalanDOMString&               pattern,
            const XalanDOMString&               dfsName,
            XalanDOMString&                     theResult,
            const XalanNode*                    context = 0,
            const LocatorType*                  locator = 0) = 0;

    // These interfaces are inherited from ExecutionContext...

    virtual void
    error(
            const XalanDOMString&   msg,
            const XalanNode*        sourceNode = 0,
            const LocatorType*      locator = 0) const = 0;

    virtual void
    warn(
            const XalanDOMString&   msg,
            const XalanNode*        sourceNode = 0,
            const LocatorType*      locator = 0) const = 0;

    virtual void
    message(
            const XalanDOMString&   msg,
            const XalanNode*        sourceNode = 0,
            const LocatorType*      locator = 0) const = 0;

protected:

    XObjectFactory*     m_xobjectFactory;
};



XALAN_CPP_NAMESPACE_END



#endif  // XPATHEXECUTIONCONTEXT_HEADER_GUARD_1357924680

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Xalan-C++ XSLT Processor Version 1.9 Copyright © 1999-2004 The Apache Software Foundation. All Rights Reserved.