RetroShare/plugins/FeedReader/util/XPathWrapper.cpp
2018-11-11 14:24:46 +01:00

119 lines
3.0 KiB
C++

/*******************************************************************************
* plugins/FeedReader/util/XPathWrapper.cpp *
* *
* Copyright (C) 2012 by Thunder <retroshare.project@gmail.com> *
* *
* This program is free software: you can redistribute it and/or modify *
* it under the terms of the GNU Affero General Public License as *
* published by the Free Software Foundation, either version 3 of the *
* License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Affero General Public License for more details. *
* *
* You should have received a copy of the GNU Affero General Public License *
* along with this program. If not, see <https://www.gnu.org/licenses/>. *
* *
*******************************************************************************/
#include "XPathWrapper.h"
#include "XMLWrapper.h"
XPathWrapper::XPathWrapper(XMLWrapper &xmlWrapper) : mXMLWrapper(xmlWrapper)
{
mContext = NULL;
mResult = NULL;
}
XPathWrapper::~XPathWrapper()
{
cleanup();
}
void XPathWrapper::cleanup()
{
if (mResult) {
xmlXPathFreeObject(mResult);
mResult = NULL;
}
if (mContext) {
xmlXPathFreeContext(mContext);
mContext = NULL;
}
}
bool XPathWrapper::compile(const char *expression)
{
cleanup();
xmlDocPtr document = mXMLWrapper.getDocument();
if (!document) {
return false;
}
mContext = xmlXPathNewContext(document);
if (!mContext) {
cleanup();
return false;
}
xmlChar *xmlExpression = NULL;
if (!mXMLWrapper.convertFromString(expression, xmlExpression)) {
cleanup();
return false;
}
mResult = xmlXPathEvalExpression(xmlExpression, mContext);
xmlFree(xmlExpression);
return true;
}
xmlXPathObjectType XPathWrapper::type()
{
if (mResult) {
return mResult->type;
}
return XPATH_UNDEFINED;
}
unsigned int XPathWrapper::count()
{
if (!mResult) {
return 0;
}
if (mResult->type != XPATH_NODESET) {
return 0;
}
if (xmlXPathNodeSetIsEmpty(mResult->nodesetval)) {
return 0;
}
return mResult->nodesetval->nodeNr;
}
xmlNodePtr XPathWrapper::node(unsigned int index)
{
if (!mResult) {
return NULL;
}
if (mResult->type != XPATH_NODESET) {
return NULL;
}
if (xmlXPathNodeSetIsEmpty(mResult->nodesetval)) {
return NULL;
}
if (index >= (unsigned int) mResult->nodesetval->nodeNr) {
return NULL;
}
return mResult->nodesetval->nodeTab[index];
}