Implemented StylesheetParameterGuard class

* removes responsibility for clearing parameters from the generate member methods
* abstracts parameter escaping and setting and handles map conversion
* marked actual generate member method as private and added StylesheetParameterGuard reference argument
** "frontend" generate member methods instantiate a StylesheetParameterGuard instance and pass it to the actual generate method
** this enables central default parameter definition while offering the possibility for custom parameters

5 files changed, 103 insertions, 30 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2171d0f..bb3e319 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,6 +28,7 @@ set(
 	src/function/read_xml_file.cc
 	src/function/read_directory.cc
 	src/support/filesystem_context.cc
+	src/support/stylesheet_parameter_guard.cc
 	src/support/dom/document_cache.cc
 	src/support/dom/document_cache_item.cc
 )
diff --git a/src/support/stylesheet_parameter_guard.cc b/src/support/stylesheet_parameter_guard.cc
new file mode 100644
index 0000000..f82c2d5
--- /dev/null
+++ b/src/support/stylesheet_parameter_guard.cc
@@ -0,0 +1,36 @@
+#include "stylesheet_parameter_guard.h"
+
+namespace InputXSLT {
+
+StylesheetParameterGuard::StylesheetParameterGuard(
+	xalan::XalanTransformer& transformer
+): transformer_(transformer) { }
+
+StylesheetParameterGuard::StylesheetParameterGuard(
+	xalan::XalanTransformer& transformer,
+	const map& parameters
+): transformer_(transformer) {
+	this->set(parameters);
+}
+
+StylesheetParameterGuard::~StylesheetParameterGuard() {
+	this->transformer_.clearStylesheetParams();
+}
+
+void StylesheetParameterGuard::set(const map& parameters) {
+	for ( auto&& parameter : parameters ) {
+		this->set(parameter.first, parameter.second);
+	}
+}
+
+void StylesheetParameterGuard::set(
+	const std::string& key,
+	const std::string& value
+) {
+	this->transformer_.setStylesheetParam(
+		key.data(),
+		std::string("'" + value + "'").data()
+	);
+}
+
+}
diff --git a/src/support/stylesheet_parameter_guard.h b/src/support/stylesheet_parameter_guard.h
new file mode 100644
index 0000000..f0622ad
--- /dev/null
+++ b/src/support/stylesheet_parameter_guard.h
@@ -0,0 +1,35 @@
+#ifndef INPUTXSLT_SRC_SUPPORT_STYLESHEET_PARAMETER_GUARD_H_
+#define INPUTXSLT_SRC_SUPPORT_STYLESHEET_PARAMETER_GUARD_H_
+
+#include <xalanc/XalanTransformer/XalanTransformer.hpp>
+
+#include <string>
+#include <unordered_map>
+
+#include "common.h"
+
+namespace InputXSLT {
+
+class StylesheetParameterGuard {
+	public:
+		typedef std::unordered_map<std::string, std::string> map;
+
+		explicit StylesheetParameterGuard(xalan::XalanTransformer&);
+		StylesheetParameterGuard(
+			xalan::XalanTransformer&,
+			const map&
+		);
+
+		~StylesheetParameterGuard();
+
+		void set(const map&);
+		void set(const std::string&, const std::string&);
+
+	private:
+		xalan::XalanTransformer& transformer_;
+
+};
+
+}
+
+#endif  // INPUTXSLT_SRC_SUPPORT_STYLESHEET_PARAMETER_GUARD_H_
diff --git a/src/transformation_facade.cc b/src/transformation_facade.cc
index b411b38..698cdb1 100644
--- a/src/transformation_facade.cc
+++ b/src/transformation_facade.cc
@@ -26,14 +26,34 @@ TransformationFacade::~TransformationFacade() {
 }
 
 int TransformationFacade::generate(const std::string& target) {
+	StylesheetParameterGuard guard(this->transformer_);
+
+	return this->generate(target, guard);
+}
+
+int TransformationFacade::generate(
+	const std::string& target,
+	const StylesheetParameterGuard::map& parameters
+) {
+	StylesheetParameterGuard guard(this->transformer_, parameters);
+
+	return this->generate(target, guard);
+}
+
+int TransformationFacade::generate(
+	const std::string& target,
+	StylesheetParameterGuard& parameters
+) {
 	const boost::filesystem::path targetFilePath(
 		boost::filesystem::absolute(target)
 	);
 
-	this->setParameters({
-		{ "target-file",      targetFilePath.filename().string()               },
-		{ "parent-directory", targetFilePath.parent_path().filename().string() }
-	});
+	parameters.set(
+		"target-file",      targetFilePath.filename().string()
+	);
+	parameters.set(
+		"parent-directory", targetFilePath.parent_path().filename().string()
+	);
 
 	std::stringstream       emptyStream("<dummy/>");
 	xalan::XSLTInputSource  inputSource(emptyStream);
@@ -49,27 +69,7 @@ int TransformationFacade::generate(const std::string& target) {
 		std::cerr << this->transformer_.getLastError() << std::endl;
 	}
 
-	this->transformer_.clearStylesheetParams();
-
 	return resultCode;
 }
 
-int TransformationFacade::generate(
-	const std::string& target,
-	const parameter_map& parameters
-) {
-	this->setParameters(parameters);
-
-	return this->generate(target);
-}
-
-void TransformationFacade::setParameters(const parameter_map& parameters) {
-	for ( auto&& parameter : parameters ) {
-		this->transformer_.setStylesheetParam(
-			parameter.first.data(),
-			std::string("'" + parameter.second + "'").data()
-		);
-	}
-}
-
 }
diff --git a/src/transformation_facade.h b/src/transformation_facade.h
index 4dc087b..3172daa 100644
--- a/src/transformation_facade.h
+++ b/src/transformation_facade.h
@@ -4,28 +4,29 @@
 #include <xalanc/XalanTransformer/XalanTransformer.hpp>
 
 #include <string>
-#include <unordered_map>
 
 #include "common.h"
+#include "support/stylesheet_parameter_guard.h"
 
 namespace InputXSLT {
 
 class TransformationFacade {
 	public:
-		typedef std::unordered_map<std::string, std::string> parameter_map;
-
-		TransformationFacade(const std::string&);
+		explicit TransformationFacade(const std::string&);
 		~TransformationFacade();
 
 		int generate(const std::string&);
-		int generate(const std::string&, const parameter_map&);
+		int generate(
+			const std::string&,
+			const StylesheetParameterGuard::map&
+		);
 
 	private:
 		const xalan::XalanCompiledStylesheet* transformation_;
 
 		xalan::XalanTransformer transformer_;
 
-		void setParameters(const parameter_map&);
+		int generate(const std::string&, StylesheetParameterGuard&);
 
 };