Improved TransformationFacade error handling

* ErrorHandler class created in 5859cb6 now caches all errors instead of pushing them to std::cerr
** cached errors are retrieved by TransformationFacade's "generate" member method
* test frontend pushes all errors to std::cerr
* FunctionTransform returns errors to the calling template as XML
** FunctionTransform test case demonstrates how one may test for successful transformation
* "generate" member method returns std::string vector wrapped in a std::unique_ptr
** this is used as a kind of optional pointer, as the std::unique_ptr instance only wraps a vector if errors where actually generated

1 files changed, 13 insertions, 11 deletions

diff --git a/src/transformation_facade.h b/src/transformation_facade.h
index ab76cac..28d1895 100644
--- a/src/transformation_facade.h
+++ b/src/transformation_facade.h
@@ -14,17 +14,19 @@ namespace InputXSLT {
 
 class TransformationFacade {
 	public:
+		typedef ErrorHandler::error_cache_ptr return_type;
+
 		TransformationFacade(const std::string&, IncludeEntityResolver*);
 		~TransformationFacade();
 
 		template <typename Target>
-		int generate(Target&);
+		return_type generate(Target&);
 
 		template <typename Target>
-		int generate(Target&, const StylesheetParameterGuard::map&);
+		return_type generate(Target&, const StylesheetParameterGuard::map&);
 
 		template <typename Target>
-		int generate(Target&, const xalan::XObjectPtr&);
+		return_type generate(Target&, const xalan::XObjectPtr&);
 
 	private:
 		const xalan::XalanCompiledStylesheet* transformation_;
@@ -32,34 +34,34 @@ class TransformationFacade {
 		xalan::XalanTransformer transformer_;
 		ErrorHandler error_handler_;
 
-		int generate(const std::string&, StylesheetParameterGuard&);
-		int generate(std::basic_ostream<char>&, StylesheetParameterGuard&);
-		int generate(xalan::XSLTResultTarget&&, StylesheetParameterGuard&);
+		return_type generate(const std::string&, StylesheetParameterGuard&);
+		return_type generate(std::basic_ostream<char>&, StylesheetParameterGuard&);
+		return_type generate(xalan::XSLTResultTarget&&, StylesheetParameterGuard&);
 
 };
 
 template <typename Target>
-int TransformationFacade::generate(Target& target) {
+auto TransformationFacade::generate(Target& target) -> return_type {
 	StylesheetParameterGuard guard(this->transformer_);
 
 	return this->generate(target, guard);
 }
 
 template <typename Target>
-int TransformationFacade::generate(
+auto TransformationFacade::generate(
 	Target& target,
 	const StylesheetParameterGuard::map& parameters
-) {
+) -> return_type {
 	StylesheetParameterGuard guard(this->transformer_, parameters);
 
 	return this->generate(target, guard);
 }
 
 template <typename Target>
-int TransformationFacade::generate(
+auto TransformationFacade::generate(
 	Target& target,
 	const xalan::XObjectPtr& parameter
-) {
+) -> return_type {
 	StylesheetParameterGuard guard(this->transformer_);
 	guard.set("parameters", parameter);