Revamped external execute function into a external text formatter function

* importing XML output of a called executable into the result document required special logic which clashed with a general execute function
* general execute function may be implemented in the future
** support for external text formatters with XML output has a higher priority
* current implementation enables calling a markdown parser and including the XHTML output into the document

1 files changed, 103 insertions, 0 deletions

diff --git a/src/function/external_text_formatter.cc b/src/function/external_text_formatter.cc
new file mode 100644
index 0000000..d1b9e92
--- /dev/null
+++ b/src/function/external_text_formatter.cc
@@ -0,0 +1,103 @@
+#include "external_text_formatter.h"
+
+#include <xalanc/XSLT/XSLTInputSource.hpp>
+
+#include <xercesc/dom/DOMDocument.hpp>
+#include <xercesc/dom/DOMImplementation.hpp>
+#include <xercesc/dom/DOMElement.hpp>
+#include <xercesc/parsers/XercesDOMParser.hpp>
+
+#include <boost/process.hpp>
+
+#include <sstream>
+
+#include "support/xerces_string_guard.h"
+#include "support/dom/result_node_facade.h"
+
+namespace {
+
+using InputXSLT::XercesStringGuard;
+
+inline xercesc::DOMNode* importDocumentElement(
+	boost::process::pistream& outputStream,
+	xercesc::DOMDocument* const domDocument
+) {
+	std::stringstream xmlStream(
+		"<output>" + std::string(
+			(std::istreambuf_iterator<char>(outputStream)),
+			(std::istreambuf_iterator<char>())
+		) + "</output>"
+	);
+
+	xercesc::XercesDOMParser parser;
+	parser.parse(xalan::XSLTInputSource(xmlStream));
+
+	return domDocument->importNode(
+		parser.getDocument()->getDocumentElement(),
+		true
+	);
+}
+
+}
+
+namespace InputXSLT {
+
+xercesc::DOMDocument* FunctionExternalTextFormatter::constructDocument(
+	const InputXSLT::FilesystemContext&,
+	const FunctionBase::parameter_tuple& parameters
+) {
+	const std::string& formatterPath(
+		std::get<0>(parameters)
+	);
+
+	const std::string& stdinText(
+		std::get<1>(parameters)
+	);
+
+	xercesc::DOMDocument* const domDocument(
+		xercesc::DOMImplementation::getImplementation()->createDocument(
+			nullptr,
+			*XercesStringGuard<XMLCh>("content"),
+			nullptr
+		)
+	);
+
+	xercesc::DOMNode* const rootNode(
+		domDocument->getDocumentElement()
+	);
+
+	boost::process::context context;
+	context.stdout_behavior = boost::process::capture_stream();
+	context.stdin_behavior  = boost::process::capture_stream();
+
+	boost::process::child formatterProcess(
+		boost::process::launch(
+			formatterPath,
+			std::vector<std::string>{""},
+			context
+		)
+	);
+
+	boost::process::postream& inputStream  = formatterProcess.get_stdin();
+	boost::process::pistream& outputStream = formatterProcess.get_stdout();
+
+	inputStream << stdinText;
+	inputStream.close();
+
+	boost::process::status status = formatterProcess.wait();
+
+	if ( status.exited() ) {
+		ResultNodeFacade result(domDocument, rootNode, "result");
+
+		result.setValueNode("code", std::to_string(status.exit_status()));
+		result.setContent(importDocumentElement(outputStream, domDocument));
+	} else {
+		ResultNodeFacade result(domDocument, rootNode, "error");
+
+		result.setValueNode("code", std::to_string(status.exit_status()));
+	}
+
+	return domDocument;
+}
+
+}