Implemented basic XML reading capabilities

* command "read-xml-file" reads a XML file and allows it to be transformed by the calling XSLT
* this will allow workflows like the following:
** a tranformation reads all the markdown files in a directory
** these markdown files are converted to a xml representation by a external function calling a appropriate C++ markdown parser
** the XML representation of each markdown file is converted to XHTML inside the XSL transformation
** ... and embedded into the output XHTML document
** => all inside a single XSL tranformation
*** i.e. it is provided with only a empty dummy XML input file and fetches the actual input by itself
* as all current code contained within this repository this is just a quick and dirty proof-of-concept and not in any way good code

3 files changed, 66 insertions, 4 deletions

diff --git a/src/read_file_command.h b/src/read_file_command.h
index 094bb3d..837ec04 100644
--- a/src/read_file_command.h
+++ b/src/read_file_command.h
@@ -9,7 +9,7 @@
 
 namespace xalan = xalanc_1_11;
 
-class FunctionFileRead : public xalan::Function {
+class FunctionReadFile : public xalan::Function {
 	public:
 		virtual xalan::XObjectPtr execute(
 			xalan::XPathExecutionContext&      executionContext,
@@ -43,7 +43,7 @@ class FunctionFileRead : public xalan::Function {
 			);
 		}
 
-		virtual FunctionFileRead* clone(xalan::MemoryManager& manager) const {
+		virtual FunctionReadFile* clone(xalan::MemoryManager& manager) const {
 			return xalan::XalanCopyConstruct(manager, *this);
 		}
 
@@ -55,7 +55,7 @@ class FunctionFileRead : public xalan::Function {
 		}
 
 	private:
-		FunctionFileRead& operator=(const FunctionFileRead&);
-		bool operator==(const FunctionFileRead&) const;
+		FunctionReadFile& operator=(const FunctionReadFile&);
+		bool operator==(const FunctionReadFile&) const;
 
 };
diff --git a/src/read_xml_file_command.h b/src/read_xml_file_command.h
new file mode 100644
index 0000000..96b6c5d
--- /dev/null
+++ b/src/read_xml_file_command.h
@@ -0,0 +1,57 @@
+#include <xalanc/Include/PlatformDefinitions.hpp>
+#include <xercesc/util/PlatformUtils.hpp>
+#include <xalanc/XalanTransformer/XalanTransformer.hpp>
+#include <xalanc/XPath/XObjectFactory.hpp>
+#include <xalanc/XPath/Function.hpp>
+#include <xalanc/XPath/XObject.hpp>
+#include <xalanc/XercesParserLiaison/XercesParserLiaison.hpp>
+
+#include "utility.h"
+
+namespace xalan = xalanc_1_11;
+
+class FunctionReadXmlFile : public xalan::Function {
+	public:
+		virtual xalan::XObjectPtr execute(
+			xalan::XPathExecutionContext&      executionContext,
+			xalan::XalanNode*                  context,
+			const xalan::Function::XObjectArgVectorType& args,
+			const xalan::Locator*              locator
+		) const {
+			if ( args.size() != 1 ) {
+				xalan::XPathExecutionContext::GetAndReleaseCachedString guard(
+					executionContext
+				);
+
+				generalError(executionContext, context, locator);
+			}
+
+			if ( this->liaison == nullptr ) {
+				const_cast<FunctionReadXmlFile*>(this)->liaison = new xalan::XercesParserLiaison();
+			}
+
+			xalan::XSLTInputSource file(args[0]->str());
+
+			return executionContext.getXObjectFactory().createNodeSet(
+				liaison->parseXMLStream(file)
+			);
+		}
+
+		virtual FunctionReadXmlFile* clone(xalan::MemoryManager& manager) const {
+			return xalan::XalanCopyConstruct(manager, *this);
+		}
+
+	protected:
+		xalan::XercesParserLiaison* liaison = nullptr;
+
+		const xalan::XalanDOMString& getError(xalan::XalanDOMString& result) const {
+			result.assign("The read-file() function expects one argument.");
+
+			return result;
+		}
+
+	private:
+		FunctionReadXmlFile& operator=(const FunctionReadXmlFile&);
+		bool operator==(const FunctionReadXmlFile&) const;
+
+};
diff --git a/src/utility.h b/src/utility.h
index 7050cee..9c88b38 100644
--- a/src/utility.h
+++ b/src/utility.h
@@ -1,3 +1,6 @@
+#ifndef UTILITY_H_
+#define UTILITY_H_
+
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
@@ -46,3 +49,5 @@ std::string readFile(const std::string& path) {
 		return content;
 	}
 }
+
+#endif  // UTILITY_H_