Function copyTag

src/3rdparty/QXlsx/source/xlsxdocument.cpp:70–154

namespace xlsxDocumentCpp {
	std::string copyTag(const std::string &sFrom, const std::string &sTo, const std::string &tag) {
		const std::string tagToFindStart = "<" + tag;
		const std::string tagToFindEnd = "</" + tag;
		const std::string tagEnd = "</" + tag + ">";

		// search all occurrences of tag in 'sFrom'
		std::string sFromData = "";
		size_t startIndex = 0;
		while (true) {
			std::size_t startPos = sFrom.find(tagToFindStart, startIndex);
			if (startPos != std::string::npos) {
				std::size_t endPos = sFrom.find(tagToFindEnd, startPos);
				std::string tagEndTmp = tagEnd;
				if (endPos == std::string::npos) {	// second try to find the ending, maybe it is "/>" 
					endPos = sFrom.find("/>", startPos);
					tagEndTmp = "/>";
				}
				if (endPos != std::string::npos) {
					sFromData += sFrom.substr(startPos, endPos - startPos) + tagEndTmp;
					startIndex = endPos + strlen(tagEndTmp.c_str());
				}
				else {
					break;
				}
			}
			else {
				break;
			}
		}

		std::string sOut = sTo; // copy 'sTo' in the output string

		if (!sFromData.empty()) { // tag found in 'from'?
								  // search all occurrences of tag in 'sOut' and delete them
			int firstPosTag = -1;
			while (true) {
				std::size_t startPos = sOut.find(tagToFindStart);
				if (startPos != std::string::npos) {
					std::size_t endPos = sOut.find(tagToFindEnd);
					std::string tagEndTmp = tagEnd;
					if (endPos == std::string::npos) {	// second try to find the ending, maybe it is "/>" 
						endPos = sOut.find("/>", startPos);
						tagEndTmp = "/>";
					}
					if (endPos != std::string::npos) {
						if (firstPosTag < 0)
							firstPosTag = startPos;
						std::string stringBefore = sOut.substr(0, startPos);
						endPos += strlen(tagEndTmp.c_str());
						std::string stringAfter = sOut.substr(endPos, strlen(sOut.c_str()) - endPos);
						sOut = stringBefore + stringAfter;
					}
					else {
						break;
					}
				}
				else {
					break;