XmlTools.cpp

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#include "XmlTools.hpp"

#include <iostream>

#include <xercesc/dom/DOM.hpp>
#include <xercesc/util/PlatformUtils.hpp>
#include <xercesc/util/QName.hpp>
#include <xercesc/util/XMLUniDefs.hpp> // chLatin_*
#include <xercesc/framework/Wrapper4InputSource.hpp>
#include <xercesc/validators/common/Grammar.hpp>

#include <xsd/cxx/xml/sax/std-input-source.hxx>
#include <xsd/cxx/xml/dom/bits/error-handler-proxy.hxx>
#include <xsd/cxx/tree/exceptions.hxx>

#include "Exception.hpp"

xsd::cxx::xml::dom::auto_ptr<xercesc::DOMDocument> XmlTools::ReadXmlFile(
    const std::string& rFileName,
    const ::xsd::cxx::tree::properties<char>& rProps,
    bool validate)
{
    xsd::cxx::xml::dom::auto_ptr<xercesc::DOMDocument> p_doc;
    try
    {
        // Initialise Xerces
        xercesc::XMLPlatformUtils::Initialize();
        // Set up an error handler
        ::xsd::cxx::tree::error_handler<char> error_handler;
        // Parse XML to DOM
        p_doc = XmlTools::ReadFileToDomDocument(rFileName, error_handler, rProps, validate);
        // Any errors?
        error_handler.throw_if_failed< ::xsd::cxx::tree::parsing<char> >();
    }
    catch (const ::xsd::cxx::tree::parsing<char>& e)
    {
        Finalize();
        // Test for missing schema/xml file
#if (XSD_INT_VERSION >= 3000000L)
        const ::xsd::cxx::tree::diagnostics<char>& diags = e.diagnostics();
        const ::xsd::cxx::tree::error<char>& first_error = diags[0];
#else
        const ::xsd::cxx::tree::errors<char>& errors = e.errors();
        const ::xsd::cxx::tree::error<char>& first_error = errors[0];
#endif
        if (first_error.line() == 0u)
        {
            std::cerr << first_error << std::endl;
            EXCEPTION("Missing file parsing configuration file: " + rFileName);
        }
        else
        {
            std::cerr << e << std::endl;
            EXCEPTION("XML parsing error in configuration file: " + rFileName);
        }
    }
// LCOV_EXCL_START
    catch (...)
    { // This shouldn't happen, but just in case...
        Finalize();
        throw;
    }
// LCOV_EXCL_STOP
    return p_doc;
}


void XmlTools::Finalize()
{
    xercesc::XMLPlatformUtils::Terminate();
}

XmlTools::Finalizer::Finalizer(bool init)
{
    // The init=true case will very rarely be used, but a parameter to the constructor is needed
    // to stop some compilers complaining about an unused variable!
    if (init)
    {
// LCOV_EXCL_START
        xercesc::XMLPlatformUtils::Initialize();
// LCOV_EXCL_STOP
    }
}

XmlTools::Finalizer::~Finalizer()
{
    XmlTools::Finalize();
}

xsd::cxx::xml::dom::auto_ptr<xercesc::DOMDocument> XmlTools::ReadFileToDomDocument(
        const std::string& rFileName,
        ::xsd::cxx::xml::error_handler<char>& rErrorHandler,
        const ::xsd::cxx::tree::properties<char>& rProps,
        bool validate)
{
    using namespace xercesc;
    namespace xml = xsd::cxx::xml;

    // Get an implementation of the Load-Store (LS) interface.
    const XMLCh ls_id [] = {chLatin_L, chLatin_S, chNull};
    DOMImplementation* p_impl(DOMImplementationRegistry::getDOMImplementation(ls_id));

#if _XERCES_VERSION >= 30000
    // Xerces-C++ 3.0.0 and later.
    xml::dom::auto_ptr<DOMLSParser> p_parser(p_impl->createLSParser(DOMImplementationLS::MODE_SYNCHRONOUS, 0));
    DOMConfiguration* p_conf(p_parser->getDomConfig());

    // Discard comment nodes in the document.
    p_conf->setParameter(XMLUni::fgDOMComments, false);

    // Enable datatype normalization.
    p_conf->setParameter(XMLUni::fgDOMDatatypeNormalization, true);

    // Do not create EntityReference nodes in the DOM tree.  No
    // EntityReference nodes will be created, only the nodes
    // corresponding to their fully expanded substitution text
    // will be created.
    p_conf->setParameter(XMLUni::fgDOMEntities, false);

    // Perform namespace processing.
    p_conf->setParameter(XMLUni::fgDOMNamespaces, true);

    // Do not include ignorable whitespace in the DOM tree.
    p_conf->setParameter(XMLUni::fgDOMElementContentWhitespace, false);

    // Enable validation.
    if (validate)
    {
        p_conf->setParameter(XMLUni::fgDOMValidate, true);
        p_conf->setParameter(XMLUni::fgXercesSchema, true);
        p_conf->setParameter(XMLUni::fgXercesSchemaFullChecking, false);
        // Code taken from xsd/cxx/xml/dom/parsing-source.txx
        if (!rProps.schema_location().empty())
        {
            xml::string locn(rProps.schema_location());
            const void* p_locn(locn.c_str());
            p_conf->setParameter(XMLUni::fgXercesSchemaExternalSchemaLocation,
                                 const_cast<void*>(p_locn));
        }
        if (!rProps.no_namespace_schema_location().empty())
        {
            xml::string locn(rProps.no_namespace_schema_location());
            const void* p_locn(locn.c_str());

            p_conf->setParameter(XMLUni::fgXercesSchemaExternalNoNameSpaceSchemaLocation,
                                 const_cast<void*>(p_locn));
        }
    }
    else
    {
        // This branch is only used by projects
// LCOV_EXCL_START
        p_conf->setParameter(XMLUni::fgDOMValidate, false);
        p_conf->setParameter(XMLUni::fgXercesSchema, false);
        p_conf->setParameter(XMLUni::fgXercesSchemaFullChecking, false);
// LCOV_EXCL_STOP
    }

    // We will release the DOM document ourselves.
    p_conf->setParameter(XMLUni::fgXercesUserAdoptsDOMDocument, true);

    // Set error handler.
    xml::dom::bits::error_handler_proxy<char> ehp(rErrorHandler);
    p_conf->setParameter(XMLUni::fgDOMErrorHandler, &ehp);

#else // _XERCES_VERSION >= 30000
    // Same as above but for Xerces-C++ 2 series.
    xml::dom::auto_ptr<DOMBuilder> p_parser(p_impl->createDOMBuilder(DOMImplementationLS::MODE_SYNCHRONOUS, 0));

    p_parser->setFeature(XMLUni::fgDOMComments, false);
    p_parser->setFeature(XMLUni::fgDOMDatatypeNormalization, true);
    p_parser->setFeature(XMLUni::fgDOMEntities, false);
    p_parser->setFeature(XMLUni::fgDOMNamespaces, true);
    p_parser->setFeature(XMLUni::fgDOMWhitespaceInElementContent, false);
    p_parser->setFeature(XMLUni::fgXercesUserAdoptsDOMDocument, true);

    // Code taken from xsd/cxx/xml/dom/parsing-source.txx
    if (validate)
    {
        p_parser->setFeature(XMLUni::fgDOMValidation, true);
        p_parser->setFeature(XMLUni::fgXercesSchema, true);
        p_parser->setFeature(XMLUni::fgXercesSchemaFullChecking, false);
        if (!rProps.schema_location().empty())
        {
            xml::string locn(rProps.schema_location());
            const void* p_locn(locn.c_str());
            p_parser->setProperty(XMLUni::fgXercesSchemaExternalSchemaLocation,
                                  const_cast<void*>(p_locn));
        }

        if (!rProps.no_namespace_schema_location().empty())
        {
            xml::string locn(rProps.no_namespace_schema_location());
            const void* p_locn(locn.c_str());

            p_parser->setProperty(XMLUni::fgXercesSchemaExternalNoNameSpaceSchemaLocation,
                                  const_cast<void*>(p_locn));
        }
    }
    else
    {
        // This branch is only used by projects
// LCOV_EXCL_START
        p_parser->setFeature(XMLUni::fgDOMValidation, false);
        p_parser->setFeature(XMLUni::fgXercesSchema, false);
        p_parser->setFeature(XMLUni::fgXercesSchemaFullChecking, false);
// LCOV_EXCL_STOP
    }

    xml::dom::bits::error_handler_proxy<char> ehp(rErrorHandler);
    p_parser->setErrorHandler(&ehp);

#endif // _XERCES_VERSION >= 30000

    // Do the parse
    xml::dom::auto_ptr<DOMDocument> p_doc(p_parser->parseURI(rFileName.c_str()));

    if (ehp.failed())
    {
        p_doc.reset();
    }

    return p_doc;
}

// LCOV_EXCL_START
void XmlTools::PrintNode(const std::string& rMsg, xercesc::DOMNode* pNode, bool showChildren)
{
    std::string prefix = X2C(pNode->getPrefix());
    std::string name = X2C(pNode->getLocalName());
    std::string nsuri = X2C(pNode->getNamespaceURI());
    std::cout << rMsg << " " << pNode << " " << prefix << ":" << name << " in " << nsuri << std::endl;
    if (showChildren)
    {
        for (xercesc::DOMNode* p_node = pNode->getFirstChild();
             p_node != NULL;
             p_node = p_node->getNextSibling())
        {
            std::cout << "     child type " << p_node->getNodeType();
            PrintNode("", p_node, false);
        }
        xercesc::DOMNamedNodeMap* p_attrs = pNode->getAttributes();
        if (p_attrs)
        {
            for (XMLSize_t i=0; i<p_attrs->getLength(); i++)
            {
                 xercesc::DOMNode* p_attr = p_attrs->item(i);
                 std::string value = X2C(p_attr->getNodeValue());
                 PrintNode("     attr (" + value + ")", p_attr, false);
            }
        }
    }
}
// LCOV_EXCL_STOP

xercesc::DOMElement* XmlTools::SetNamespace(xercesc::DOMDocument* pDocument,
                                            xercesc::DOMElement* pElement,
                                            const XMLCh* pNamespace)
{
    using namespace xercesc;

    //PrintNode("Renaming", pElement, true);
    DOMNamedNodeMap* p_orig_attrs = pElement->getAttributes();
    std::vector<std::string> attr_values;
    if (p_orig_attrs)
    {
        for (XMLSize_t i=0; i<p_orig_attrs->getLength(); i++)
        {
            DOMNode* p_attr = p_orig_attrs->item(i);
            attr_values.push_back(X2C(p_attr->getNodeValue()));
        }
    }
    DOMElement* p_new_elt = static_cast<DOMElement*>(
        pDocument->renameNode(pElement, pNamespace, pElement->getLocalName()));
    //PrintNode("   to", p_new_elt, true);
    // Fix attributes - some get broken by the rename!
    if (p_orig_attrs)
    {
        DOMNamedNodeMap* p_new_attrs = p_new_elt->getAttributes();
        assert(p_new_attrs);
        assert(p_new_attrs == p_orig_attrs);
        assert(p_new_attrs->getLength() == attr_values.size());
        for (XMLSize_t i=0; i<p_new_attrs->getLength(); i++)
        {
            DOMNode* p_attr = p_new_attrs->item(i);
            p_attr->setNodeValue(X(attr_values[i]));
        }
    }
    //PrintNode("   after attr fix", p_new_elt, true);

    std::vector<DOMElement*> children = GetChildElements(p_new_elt);
    for (std::vector<DOMElement*>::iterator it = children.begin(); it != children.end(); ++it)
    {
        SetNamespace(pDocument, *it, pNamespace);
    }

    return p_new_elt;
}

xercesc::DOMElement* XmlTools::SetNamespace(xercesc::DOMDocument* pDocument,
                                            xercesc::DOMElement* pElement,
                                            const std::string& rNamespace)
{
    return SetNamespace(pDocument, pElement, X(rNamespace));
}


std::vector<xercesc::DOMElement*> XmlTools::GetChildElements(const xercesc::DOMElement* pElement)
{
    std::vector<xercesc::DOMElement*> children;
    for (xercesc::DOMNode* p_node = pElement->getFirstChild();
         p_node != NULL;
         p_node = p_node->getNextSibling())
    {
        if (p_node->getNodeType() == xercesc::DOMNode::ELEMENT_NODE)
        {
            children.push_back(static_cast<xercesc::DOMElement*>(p_node));
        }
    }
    return children;
}


void XmlTools::FindElements(const xercesc::DOMElement* pContextElement,
                            const std::vector<std::string>& rNames,
                            std::vector<xercesc::DOMElement*>& rResults,
                            unsigned depth)
{
    for (xercesc::DOMNode* p_node = pContextElement->getFirstChild();
         p_node != NULL;
         p_node = p_node->getNextSibling())
    {
        if (p_node->getNodeType() == xercesc::DOMNode::ELEMENT_NODE &&
            X2C(p_node->getLocalName()) == rNames[depth])
        {
            xercesc::DOMElement* p_child_elt = static_cast<xercesc::DOMElement*>(p_node);
            if (depth == rNames.size() - 1)
            {
                rResults.push_back(p_child_elt);
            }
            else
            {
                FindElements(p_child_elt, rNames, rResults, depth+1);
            }
        }
    }
}

std::vector<xercesc::DOMElement*> XmlTools::FindElements(const xercesc::DOMElement* pContextElement,
                                                         const std::string& rPath)
{
    std::vector<xercesc::DOMElement*> results;
    std::vector<std::string> path;
    size_t start_pos = 0;
    size_t slash_pos = 0;
    while (slash_pos != std::string::npos)
    {
        slash_pos = rPath.find('/', start_pos);
        if (slash_pos == std::string::npos)
        {
            path.push_back(rPath.substr(start_pos));
        }
        else
        {
            path.push_back(rPath.substr(start_pos, slash_pos-start_pos));
        }
        start_pos = slash_pos + 1;
    }
    FindElements(pContextElement, path, results);
    return results;
}


void XmlTools::WrapContentInElement(xercesc::DOMDocument* pDocument,
                                    xercesc::DOMElement* pElement,
                                    const XMLCh* pNewElementLocalName)
{
    const XMLCh* p_namespace_uri = pElement->getNamespaceURI();
    const XMLCh* p_prefix = pElement->getPrefix();
    const XMLCh* p_qualified_name;
    if (p_prefix)
    {
// LCOV_EXCL_START
        // We can't actually cover this code, since versions of the parameters file which need this
        // transform didn't use a namespace, so can't have a namespace prefix!
        xercesc::QName qname(p_prefix, pNewElementLocalName, 0);
        p_qualified_name = qname.getRawName();
// LCOV_EXCL_STOP
    }
    else
    {
        p_qualified_name = pNewElementLocalName;
    }
    xercesc::DOMElement* p_wrapper_elt = pDocument->createElementNS(p_namespace_uri, p_qualified_name);
    // Move all child nodes of pElement to be children of p_wrapper_elt
    xercesc::DOMNodeList* p_children = pElement->getChildNodes();
    for (unsigned i=0; i<p_children->getLength(); i++)
    {
        xercesc::DOMNode* p_child = pElement->removeChild(p_children->item(i));
        p_wrapper_elt->appendChild(p_child);
    }
    // Add the wrapper as the sole child of pElement
    pElement->appendChild(p_wrapper_elt);
}


std::string XmlTools::EscapeSpaces(const std::string& rPath)
{
    std::string escaped_path;
    for (std::string::const_iterator it = rPath.begin(); it != rPath.end(); ++it)
    {
        if (*it == ' ')
        {
            escaped_path += "%20";
        }
        else
        {
            escaped_path += *it;
        }
    }
    return escaped_path;
}