Merged "read-xml-file" and "read-file" into "read-file"

* FunctionReadFile is now able to distinguish between XML files and plain text files
** it selects the appropriate course of action automatically
** reading the file as XML into the DOM or reading it as a string
* the current selection criteria is the file extension
** I am thinking about trying to import every file into the DOM and using the result state of that action as selection criteria
* Updated README.md and test cases accordingly

1 files changed, 49 insertions, 4 deletions

diff --git a/src/function/read_file.cc b/src/function/read_file.cc
index 22e96d7..7603ad1 100644
--- a/src/function/read_file.cc
+++ b/src/function/read_file.cc
@@ -3,6 +3,8 @@
 #include <xercesc/dom/DOMDocument.hpp>
 #include <xercesc/dom/DOMImplementation.hpp>
 #include <xercesc/dom/DOMElement.hpp>
+#include <xercesc/parsers/XercesDOMParser.hpp>
+#include <xercesc/framework/LocalFileInputSource.hpp>
 
 #include "boost/filesystem/fstream.hpp"
 
@@ -11,7 +13,28 @@
 
 namespace {
 
-inline std::string readFile(const boost::filesystem::path& filePath) {
+inline bool isXmlFile(const boost::filesystem::path& filePath) {
+	return filePath.extension() == ".xml";
+}
+
+inline xercesc::DOMNode* readXmlFile(
+	const boost::filesystem::path& filePath,
+	xercesc::DOMDocument* const domDocument
+) {
+	const xercesc::LocalFileInputSource file(
+		*InputXSLT::XercesStringGuard<XMLCh>(filePath.string().data())
+	);
+
+	xercesc::XercesDOMParser parser;
+	parser.parse(file);
+
+	return domDocument->importNode(
+		parser.getDocument()->getDocumentElement(),
+		true
+	);
+}
+
+inline std::string readPlainFile(const boost::filesystem::path& filePath) {
 	boost::filesystem::ifstream file(filePath);
 
 	return std::string(
@@ -53,11 +76,33 @@ xercesc::DOMDocument* FunctionReadFile::constructDocument(
 	result.setAttribute("path", filePath.string());
 
 	if ( boost::filesystem::is_regular_file(filePath) ) {
-		result.setAttribute("result", "success");
+		try {
+			if ( isXmlFile(filePath) ) {
+				result.setAttribute("type", "xml");
+
+				result.setContent(
+					readXmlFile(filePath.string(), domDocument)
+				);
+			} else {
+				result.setAttribute("type", "plain");
+
+				result.setContent(
+					readPlainFile(filePath)
+				);
+			}
+
+			result.setAttribute("result", "success");
+		}
+		catch ( const xercesc::DOMException& exception ) {
+			result.setAttribute("result", "error");
 
-		result.setContent(readFile(filePath));
+			result.setValueNode(
+				"error",
+				*XercesStringGuard<char>(exception.msg)
+			);
+		}
 	} else {
-		result.setAttribute("result", "success");
+		result.setAttribute("result", "error");
 	}
 
 	return domDocument;