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Basic XQilla XPath Example

I am looking for a basic example of how to configure XQilla to use an XPath query in std :: string containing XML. The XQilla site example seems to use XQuery in both the file and the URL.

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This is an old question, but I was looking for the answer to this question and could not find it. Now I solved it and thought I should share the code.

- edit , the license, if necessary, for the code below, is used in conjunction with MIT and BSD or something else ...

XPathExtracter.h

#ifndef JOPPLI_XPATHEXTRACTER_H #define JOPPLI_XPATHEXTRACTER_H #include <string> #include <vector> #include <xercesc/parsers/XercesDOMParser.hpp> #include <xercesc/dom/DOM.hpp> namespace Joppli { using namespace xercesc; class XPathExtracter { public: typedef std::vector<std::string> Result; XPathExtracter(); ~XPathExtracter(); DOMDocument * getDocument(const std::string & xml); void extract(const std::string & query, DOMDocument * document, Result * result); protected: DOMLSParser * parser; DOMImplementation * xqillaImplementation; private: static int count; }; } #endif

XPathExtracter.cpp

 #include "XPathExtracter.h" #include <xercesc/framework/MemBufInputSource.hpp> #include <xqilla/xqilla-dom3.hpp> namespace Joppli { XPathExtracter::XPathExtracter() { // Initialise Xerces-C and XQilla using XQillaPlatformUtils if(count++ == 0) XQillaPlatformUtils::initialize(); // Get the XQilla DOMImplementation object this->xqillaImplementation = DOMImplementationRegistry::getDOMImplementation(X("XPath2 3.0")); this->parser = this->xqillaImplementation->createLSParser( DOMImplementationLS::MODE_SYNCHRONOUS, 0); } XPathExtracter::~XPathExtracter() { this->parser->release(); if(--count == 0) XQillaPlatformUtils::terminate(); } DOMDocument * XPathExtracter::getDocument(const std::string & xml) { /* // An alternative to simply setting the string input, as shown below MemBufInputSource * memBuf = new MemBufInputSource( (const XMLByte *) xml.c_str(), xml.size(), "xml (in memory)"); DOMLSInput * input = this->xqillaImplementation->createLSInput(); input->setByteStream(memBuf); DOMDocument * document = parser->parse(input); input->release(); delete memBuf; return document; */ DOMLSInput * input = this->xqillaImplementation->createLSInput(); XMLCh * stringData = XMLString::transcode(xml.c_str()); input->setStringData(stringData); DOMDocument * document = parser->parse(input); input->release(); delete stringData; return document; } void XPathExtracter::extract(const std::string & query, DOMDocument * document, Result * result) { // Parse an XPath 2 expression AutoRelease<DOMXPathExpression> expression( document->createExpression(X(query.c_str()), 0)); // Execute the query AutoRelease<DOMXPathResult> xQillaResult( expression->evaluate( document, DOMXPathResult::ITERATOR_RESULT_TYPE, 0)); // Iterate over the results while(xQillaResult->iterateNext()) { char * content = XMLString::transcode( xQillaResult->getStringValue()); result->push_back(content); delete content; } } int XPathExtracter::count = 0; }

main.cpp

 #include <iostream> #include "XPathExtracter.h" int main(void) { std::string * body = new std::string; // ... (logic to fill the body string with an xml/html value) // Extract using namespace xercesc; Joppli::XPathExtracter * driver = new Joppli::XPathExtracter(); Joppli::XPathExtracter::Result * results = new Joppli::XPathExtracter::Result; DOMDocument * document = driver->getDocument(*body); driver->extract("html/head//title", document, results); driver->extract("html/head//meta//@name", document, results); driver->extract("html//body//a[@id=\"link_mx_es\"]", document, results); for(const auto & result : *results) std::cout << result << std::endl; delete results; delete driver; delete body; return 0; }

I ran this code through valgrind and did not detect any leaks.

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