Implemented external "resolve-include" function

* resolves paths provided as strings against include paths provided through the newly created "--include" argument of the test executable
* this was implemented to enable central collections of XSLT libraries simmilar to how there are C headers in "/usr/include"

6 files changed, 131 insertions, 5 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8ffcb49..c5aa8ea 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,6 +28,7 @@ set(
 	src/function/read_xml_file.cc
 	src/function/read_directory.cc
 	src/function/transform.cc
+	src/function/resolve_include.cc
 	src/support/filesystem_context.cc
 	src/support/stylesheet_parameter_guard.cc
 	src/support/xalan_string.cc
diff --git a/src/function/resolve_include.cc b/src/function/resolve_include.cc
new file mode 100644
index 0000000..ac4adf5
--- /dev/null
+++ b/src/function/resolve_include.cc
@@ -0,0 +1,62 @@
+#include "resolve_include.h"
+
+#include <algorithm>
+
+#include "support/xalan_string.h"
+
+namespace InputXSLT {
+
+FunctionResolveInclude::FunctionResolveInclude(
+	const std::vector<std::string>& path):
+	path_(new std::vector<FilesystemContext>()) {
+	this->path_->reserve(path.size());
+
+	std::transform(
+		path.begin(),
+		path.end(),
+		std::back_inserter(*this->path_),
+		[](const std::string& path) -> FilesystemContext {
+			return FilesystemContext(path);
+		}
+	);
+}
+
+xalan::XObjectPtr FunctionResolveInclude::execute(
+	xalan::XPathExecutionContext& executionContext,
+	xalan::XalanNode*,
+	const xalan::XObjectPtr parameter,
+	const xalan::Locator*
+) const {
+	const std::string filePath(toString(parameter->str()));
+
+	for ( auto&& context : *this->path_ ) {
+		const boost::filesystem::path resolvedPath(
+			context.resolve(filePath)
+		);
+
+		if ( boost::filesystem::exists(resolvedPath) &&
+		     boost::filesystem::is_regular_file(resolvedPath) ) {
+			return executionContext.getXObjectFactory().createString(
+				toString(resolvedPath.string())
+			);
+		}
+	}
+
+	return executionContext.getXObjectFactory().createString(
+		toString("error")
+	);
+}
+
+FunctionResolveInclude* FunctionResolveInclude::clone(
+	xalan::MemoryManager& manager) const {
+	return xalan::XalanCopyConstruct(manager, *this);
+}
+
+const xalan::XalanDOMString& FunctionResolveInclude::getError(
+	xalan::XalanDOMString& result) const {
+	result.assign("The function expects one parameter of type string.");
+
+	return result;
+}
+
+}
diff --git a/src/function/resolve_include.h b/src/function/resolve_include.h
new file mode 100644
index 0000000..2d6e62f
--- /dev/null
+++ b/src/function/resolve_include.h
@@ -0,0 +1,44 @@
+#ifndef INPUTXSLT_SRC_FUNCTION_RESOLVE_INCLUDE_H_
+#define INPUTXSLT_SRC_FUNCTION_RESOLVE_INCLUDE_H_
+
+#include <xalanc/XPath/XObjectFactory.hpp>
+#include <xalanc/XPath/Function.hpp>
+#include <xalanc/XPath/XObject.hpp>
+
+#include "boost/filesystem.hpp"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "common.h"
+#include "support/filesystem_context.h"
+
+namespace InputXSLT {
+
+class FunctionResolveInclude : public xalan::Function {
+	public:
+		FunctionResolveInclude(const std::vector<std::string>&);
+
+		virtual xalan::XObjectPtr execute(
+			xalan::XPathExecutionContext&,
+			xalan::XalanNode*,
+			const xalan::XObjectPtr,
+			const xalan::Locator*
+		) const;
+
+		virtual FunctionResolveInclude* clone(xalan::MemoryManager&) const;
+
+		FunctionResolveInclude& operator=(const FunctionResolveInclude&) = delete;
+		bool operator==(const FunctionResolveInclude&) const             = delete;
+
+	private:
+		const std::shared_ptr<std::vector<FilesystemContext>> path_;
+
+		const xalan::XalanDOMString& getError(xalan::XalanDOMString&) const;
+
+};
+
+}
+
+#endif  // INPUTXSLT_SRC_FUNCTION_RESOLVE_INCLUDE_H_
diff --git a/src/plattform_guard.cc b/src/plattform_guard.cc
index da3b6d7..820346e 100644
--- a/src/plattform_guard.cc
+++ b/src/plattform_guard.cc
@@ -10,10 +10,11 @@
 #include "function/read_xml_file.h"
 #include "function/read_directory.h"
 #include "function/transform.h"
+#include "function/resolve_include.h"
 
 namespace InputXSLT {
 
-PlattformGuard::PlattformGuard() {
+PlattformGuard::PlattformGuard(const std::vector<std::string>& path) {
 	xercesc::XMLPlatformUtils::Initialize();
 	xalan::XalanTransformer::initialize();
 
@@ -44,6 +45,12 @@ PlattformGuard::PlattformGuard() {
 		xalan::XalanDOMString("transform"),
 		InputXSLT::FunctionTransform()
 	);
+
+	xalan::XalanTransformer::installExternalFunctionGlobal(
+		customNamespace,
+		xalan::XalanDOMString("resolve-include"),
+		InputXSLT::FunctionResolveInclude(path)
+	);
 }
 
 PlattformGuard::~PlattformGuard() {
diff --git a/src/plattform_guard.h b/src/plattform_guard.h
index 12b19f0..f6abcba 100644
--- a/src/plattform_guard.h
+++ b/src/plattform_guard.h
@@ -1,10 +1,13 @@
 #ifndef INPUTXSLT_SRC_PLATTFORM_GUARD_H_
 #define INPUTXSLT_SRC_PLATTFORM_GUARD_H_
 
+#include <string>
+#include <vector>
+
 namespace InputXSLT {
 
 struct PlattformGuard {
-	PlattformGuard();
+	PlattformGuard(const std::vector<std::string>&);
 	~PlattformGuard();
 };
 
diff --git a/test.cc b/test.cc
index 1262520..a21f25a 100644
--- a/test.cc
+++ b/test.cc
@@ -3,6 +3,8 @@
 
 #include "boost/program_options.hpp"
 
+#include <string>
+#include <vector>
 #include <iostream>
 
 int main(int ac, char** av) {
@@ -11,8 +13,9 @@ int main(int ac, char** av) {
 	);
 
 	optionDescription.add_options()
-		("transformation", boost::program_options::value<std::string>()->required(), "transformation file")
-		("target",         boost::program_options::value<std::string>(),             "target file")
+		("transformation", boost::program_options::value<std::string>()->required(),  "transformation file")
+		("target",         boost::program_options::value<std::string>(),              "target file")
+		("include",        boost::program_options::value<std::vector<std::string>>(), "include paths")
 	;
 
 	boost::program_options::variables_map variables;
@@ -32,7 +35,13 @@ int main(int ac, char** av) {
 	}
 
 	if ( variables.count("transformation") ) {
-		InputXSLT::PlattformGuard plattform;
+		std::vector<std::string> includePath;
+
+		if ( variables.count("include") ) {
+			includePath = variables["include"].as<std::vector<std::string>>();
+		};
+
+		InputXSLT::PlattformGuard plattform(includePath);
 
 		InputXSLT::TransformationFacade transformation(
 			variables["transformation"].as<std::string>()