build DOM, filter records and evaluate XPath expressions for additional output attributes
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/XMLNameCodec.h Wed Dec 30 01:28:45 2020 +0100
@@ -0,0 +1,127 @@
+/**
+ * Relational pipes
+ * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * 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, version 3 of the License.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <sstream>
+#include <iomanip>
+#include <stdexcept>
+
+#include <glibmm-2.4/glibmm/ustring.h>
+
+namespace relpipe {
+namespace in {
+namespace xmltable {
+
+class XMLNameCodec {
+private:
+ static const char DEFAULT_ESCAPING_CHARACTER = '_';
+ const char esc;
+ const bool namespaceAware;
+
+ bool between(gunichar codepoint, gunichar start, gunichar end) {
+ return codepoint >= start && codepoint <= end;
+ }
+
+ /**
+ * https://www.w3.org/TR/REC-xml/#NT-NameStartChar
+ *
+ * @param codepoint unicode character
+ * @return whether this character is allowed at the beginning of a XML name
+ */
+ bool isValidNameStartChar(gunichar codepoint) {
+ // NameStartChar ::= ":" | [A-Z] | "_" | [a-z]
+ // | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | [#x370-#x37D] | [#x37F-#x1FFF]
+ // | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF]
+ // | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
+ return (codepoint == ':' && !namespaceAware) || between(codepoint, 'A', 'Z') || codepoint == '_' || between(codepoint, 'a', 'z')
+ || between(codepoint, 0xC0, 0xD6) || between(codepoint, 0xD8, 0xF6) || between(codepoint, 0xF8, 0x2FF) || between(codepoint, 0x370, 0x37D) || between(codepoint, 0x37F, 0x1FFF)
+ || between(codepoint, 0x200C, 0x200D) || between(codepoint, 0x2070, 0x218F) || between(codepoint, 0x2C00, 0x2FEF) || between(codepoint, 0x3001, 0xD7FF)
+ || between(codepoint, 0xF900, 0xFDCF) || between(codepoint, 0xFDF0, 0xFFFD) || between(codepoint, 0x10000, 0xEFFFF);
+ }
+
+ /**
+ * https://www.w3.org/TR/REC-xml/#NT-NameChar
+ *
+ * @param codepoint unicode character
+ * @return whether this character is allowed in a XML name
+ */
+ bool isValidNameChar(gunichar codepoint) {
+ // NameChar ::= NameStartChar | "-" | "." | [0-9]
+ // | #xB7
+ // | [#x0300-#x036F] | [#x203F-#x2040]
+ return isValidNameStartChar(codepoint) || codepoint == '-' || codepoint == '.' || between(codepoint, '0', '9')
+ || codepoint == 0xB7
+ || between(codepoint, 0x0300, 0x036F) || between(codepoint, 0x203F, 0x2040);
+ }
+
+public:
+
+ XMLNameCodec() : XMLNameCodec(DEFAULT_ESCAPING_CHARACTER, true) {
+ }
+
+ /**
+ * @param escapingCharacter must be valid character allowed not only in the middle of the XML name but also as the
+ * first character of the name
+ * @param namespaceAware colon character is reserved as a separator of the prefix and the local name, see
+ * https://www.w3.org/TR/REC-xml-names/#NT-NCName
+ * @throws std::invalid_argument if escapingCharacter is not valid
+ */
+ XMLNameCodec(const char escapingCharacter, const bool namespaceAware) : esc(escapingCharacter), namespaceAware(namespaceAware) {
+ // TODO: allow also characters like #xB7 and add another escaping if they occur at the beginning of the name?
+ if (!isValidNameStartChar(esc)) {
+ throw std::invalid_argument("The character „" + std::to_string(escapingCharacter) + "“ is not allowed at the beginning of a XML name and thus not usable for escaping");
+ }
+ }
+
+ virtual ~XMLNameCodec() {
+ }
+
+ /**
+ * @param name any string
+ * @return valid name of XML element or attribute
+ */
+ Glib::ustring encode(Glib::ustring name) {
+ if (name.empty()) {
+ return Glib::ustring(1, esc);
+ } else {
+ std::stringstream result;
+
+ for (int i = 0; i < name.size(); i++) {
+ gunichar codepoint = name[i];
+ if (codepoint == esc) {
+ result.put(esc);
+ result.put(esc);
+ continue;
+ } else if ((i == 0 && isValidNameStartChar(codepoint)) || (i > 0 && isValidNameChar(codepoint))) {
+ result << Glib::ustring(1, codepoint);
+ continue;
+ }
+
+ result.put(esc);
+ result << Glib::ustring::format(std::hex, std::setfill(L'0'), std::setw(2), codepoint);
+ result.put(esc);
+ }
+
+ return result.str();
+ }
+ }
+
+};
+
+}
+}
+}
--- a/src/XPathHandler.h Wed Dec 30 00:39:03 2020 +0100
+++ b/src/XPathHandler.h Wed Dec 30 01:28:45 2020 +0100
@@ -34,6 +34,7 @@
#include <relpipe/cli/RelpipeCLIException.h>
#include "Configuration.h"
+#include "XMLNameCodec.h"
namespace relpipe {
namespace tr {
@@ -41,14 +42,18 @@
class XPathHandler : public relpipe::reader::handlers::RelationalReaderStringHandler {
private:
+ std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // XML is in UTF-8
shared_ptr<relpipe::writer::RelationalWriter> relationalWriter;
Configuration configuration;
- RelationConfiguration* currentRelationConfiguration;
+ RelationConfiguration* currentRelationConfiguration = nullptr;
std::vector<relpipe::reader::handlers::AttributeMetadata> currentReaderMetadata;
std::vector<relpipe::writer::AttributeMetadata> currentWriterMetadata;
size_t currentAttributeIndex = 0;
-
+
+
xmlpp::DomParser dom;
+ xmlpp::Element* recordElement = nullptr;
+ relpipe::in::xmltable::XMLNameCodec xmlNameCodec; // TODO: move to a common library
void copyInputAttributesToOutput() {
for (auto rm : currentReaderMetadata) currentWriterMetadata.push_back({rm.getAttributeName(), relationalWriter->toTypeId(rm.getTypeName())});
@@ -63,6 +68,35 @@
return currentRelationConfiguration->inputAttributePolicy == InputAttributePolicy::Append;
}
+ void resetRecordElement() {
+ if (recordElement) dom.get_document()->get_root_node()->remove_child(recordElement);
+ recordElement = dom.get_document()->get_root_node()->add_child("record");
+ }
+
+ const Glib::ustring s2x(relpipe::common::type::StringX value) {
+ return Glib::ustring(convertor.to_bytes(value));
+ }
+
+ const relpipe::common::type::StringX x2s(const Glib::ustring& value) {
+ return convertor.from_bytes(value);
+ }
+
+ void writeInputAttributes() {
+ for (xmlpp::Node* attributeNode : recordElement->get_children()) {
+ if (xmlpp::Element * attributeElement = dynamic_cast<xmlpp::Element*> (attributeNode)) {
+ auto value = attributeElement->get_child_text()->get_content();
+ relationalWriter->writeAttribute(x2s(value));
+ }
+ }
+ }
+
+ void writeOutputAttributes() {
+ for (auto oa : currentRelationConfiguration->outputAttributes) {
+ auto value = recordElement->eval_to_string(s2x(oa.xpath));
+ relationalWriter->writeAttribute(x2s(value));
+ }
+ }
+
public:
XPathHandler(shared_ptr<relpipe::writer::RelationalWriter> relationalWriter, Configuration configuration) : relationalWriter(relationalWriter), configuration(configuration) {
@@ -92,6 +126,8 @@
if (isAppendingInputAttributes()) copyInputAttributesToOutput();
// TODO: prepare DOM
+ dom.get_document()->create_root_node("relpipe-tr-xpath");
+ resetRecordElement();
}
relationalWriter->startRelation(name, currentWriterMetadata, true);
@@ -101,15 +137,21 @@
if (currentRelationConfiguration) {
relpipe::reader::handlers::AttributeMetadata attributeMetadata = currentReaderMetadata[currentAttributeIndex];
- // TODO: add attribute to DOM
+ xmlpp::Element* attributeElement = recordElement->add_child(xmlNameCodec.encode(s2x(attributeMetadata.getAttributeName())));
+ attributeElement->set_attribute("name", s2x(attributeMetadata.getAttributeName()));
+ attributeElement->set_attribute("type", s2x(attributeMetadata.getTypeName()));
+ attributeElement->add_child_text(s2x(value));
currentAttributeIndex++;
if (currentAttributeIndex == currentReaderMetadata.size()) {
+ if (currentRelationConfiguration->where.empty() || recordElement->eval_to_boolean(s2x(currentRelationConfiguration->where))) {
+ if (isPrependingInputAttributes()) writeInputAttributes();
+ writeOutputAttributes();
+ if (isAppendingInputAttributes()) writeInputAttributes();
+ }
- // TODO: evaluate XPath expression
- // TODO: write record to output, if the XPath condition was met
- // TODO: clean record node in DOM
+ resetRecordElement();
currentAttributeIndex = 0;
}
} else {