FeedReader plugin:

- added new classes for XML/HTML parse and modify
- added basic error handling
- added new GUI for a preview and a tree to show the structure of the page (will be continued)

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.5-gxs-b1@5412 b45a01b8-16f6-495d-af2f-9b41ad6348cc

plugins/FeedReader/util/XMLWrapper.cpp

@@ -0,0 +1,245 @@
+/****************************************************************
+ *  RetroShare GUI is distributed under the following license:
+ *
+ *  Copyright (C) 2012 by Thunder
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA  02110-1301, USA.
+ ****************************************************************/
+
+#include <iostream>
+#include <string.h>
+
+#include "XMLWrapper.h"
+
+XMLWrapper::XMLWrapper()
+{
+	mDocument = NULL;
+	mCharEncodingHandler = xmlFindCharEncodingHandler ("UTF8");
+
+	if (!mCharEncodingHandler) {
+		/* no encoding handler found */
+		std::cerr << "XMLWrapper::XMLWrapper - no encoding handler found" << std::endl;
+	}
+}
+
+XMLWrapper::~XMLWrapper()
+{
+	cleanup();
+	xmlCharEncCloseFunc(mCharEncodingHandler);
+}
+
+void XMLWrapper::cleanup()
+{
+	if (mDocument) {
+		xmlFreeDoc(mDocument);
+		mDocument = NULL;
+	}
+}
+
+bool XMLWrapper::convertToString(const xmlChar *xmlText, std::string &text)
+{
+	bool result = false;
+
+	xmlBufferPtr in = xmlBufferCreateStatic((void*) xmlText, xmlStrlen(xmlText));
+	xmlBufferPtr out = xmlBufferCreate();
+	int ret = xmlCharEncOutFunc(mCharEncodingHandler, out, in);
+	if (ret >= 0) {
+		result = true;
+		text = (char*) xmlBufferContent(out);
+	}
+
+	xmlBufferFree(in);
+	xmlBufferFree(out);
+
+	return result;
+}
+
+bool XMLWrapper::convertFromString(const char *text, xmlChar *&xmlText)
+{
+	bool result = false;
+
+	xmlBufferPtr in = xmlBufferCreateStatic((void*) text, strlen(text));
+	xmlBufferPtr out = xmlBufferCreate();
+	int ret = xmlCharEncOutFunc(mCharEncodingHandler, out, in);
+	if (ret >= 0) {
+		result = true;
+		xmlText = xmlBufferDetach(out);
+	}
+
+	xmlBufferFree(in);
+	xmlBufferFree(out);
+
+	return result;
+}
+
+xmlNodePtr XMLWrapper::getRootElement()
+{
+	if (mDocument) {
+		return xmlDocGetRootElement(mDocument);
+	}
+
+	return NULL;
+}
+
+bool XMLWrapper::readXML(const char *xml)
+{
+	cleanup();
+
+	mDocument = xmlReadDoc((const xmlChar*) xml, "", NULL, XML_PARSE_NOERROR | XML_PARSE_NOWARNING/* | XML_PARSE_COMPACT | XML_PARSE_NOCDATA*/);
+	if (mDocument) {
+		return true;
+	}
+
+	return false;
+}
+
+bool XMLWrapper::getContent(xmlNodePtr node, std::string &content)
+{
+	content.clear();
+
+	if (!node) {
+		return false;
+	}
+
+	xmlChar *xmlContent = xmlNodeListGetString(mDocument, node, 1);
+	if (!xmlContent) {
+		return true;
+	}
+
+	bool result = convertToString(xmlContent, content);
+	xmlFree(xmlContent);
+
+	return result;
+}
+
+std::string XMLWrapper::nodeName(xmlNodePtr node)
+{
+	std::string name;
+
+	if (node) {
+		convertToString(node->name, name);
+	}
+
+	return name;
+}
+
+std::string XMLWrapper::attrName(xmlAttrPtr attr)
+{
+	std::string name;
+
+	if (attr) {
+		convertToString(attr->name, name);
+	}
+
+	return name;
+}
+
+xmlNodePtr XMLWrapper::findNode(xmlNodePtr node, const char *name, bool children)
+{
+	if (node->name) {
+		if (xmlStrcasecmp(node->name, (xmlChar*) name) == 0) {
+			return node;
+		}
+	}
+
+	xmlNodePtr nodeFound = NULL;
+	if (children) {
+		if (node->children) {
+			nodeFound = findNode(node->children, name, children);
+			if (nodeFound) {
+				return nodeFound;
+			}
+		}
+	}
+
+	if (node->next) {
+		nodeFound = findNode(node->next, name, children);
+		if (nodeFound) {
+			return nodeFound;
+		}
+	}
+
+	return NULL;
+}
+
+bool XMLWrapper::getChildText(xmlNodePtr node, const char *childName, std::string &text)
+{
+	if (node == NULL || node->children == NULL) {
+		return false;
+	}
+
+	xmlNodePtr child = findNode(node->children, childName, true);
+	if (!child) {
+		return false;
+	}
+
+	if (child->type != XML_ELEMENT_NODE) {
+		return false;
+	}
+
+	if (!child->children) {
+		return false;
+	}
+
+	if (child->children->type != XML_TEXT_NODE) {
+		return false;
+	}
+
+	if (child->children->content) {
+		return convertToString(child->children->content, text);
+	}
+
+	return true;
+}
+
+std::string XMLWrapper::getAttr(xmlNodePtr node, xmlAttrPtr attr)
+{
+	return getAttr(node, (const char*) attr->name);
+}
+
+std::string XMLWrapper::getAttr(xmlNodePtr node, const char *name)
+{
+	if (!node || !name) {
+		return "";
+	}
+
+	std::string value;
+
+	xmlChar *xmlValue = xmlGetProp(node, (const xmlChar*) name);
+	if (xmlValue) {
+		convertToString(xmlValue, value);
+		xmlFree(xmlValue);
+	}
+
+	return value;
+}
+
+bool XMLWrapper::setAttr(xmlNodePtr node, const char *name, const char *value)
+{
+	if (!node || !name) {
+		return false;
+	}
+
+	xmlChar *xmlValue = NULL;
+	if (!convertFromString(value, xmlValue)) {
+		return false;
+	}
+
+	xmlAttrPtr xmlAttr = xmlSetProp (node, (const xmlChar*) name, xmlValue);
+	xmlFree(xmlValue);
+
+	return xmlAttr != NULL;
+}