Implemented basic ErrorHandler

* InputXSLT::ErrorHandler is derived from xercesc::ErrorHandler and enables contextual printing of transformation errors
** currently this means that the error messages passed to std::cerr contain the full path of the offending transformation
* added input trimming to the external transform function
** calls to this function from inside a transformation may contain unnecessary whitespace characters which disrupt further processing

5 files changed, 80 insertions, 5 deletions

diff --git a/src/function/transform.cc b/src/function/transform.cc
index fd28b34..06e4c19 100644
--- a/src/function/transform.cc
+++ b/src/function/transform.cc
@@ -4,6 +4,8 @@
 #include <xercesc/dom/DOMImplementation.hpp>
 #include <xercesc/dom/DOMElement.hpp>
 
+#include <boost/algorithm/string.hpp>
+
 #include "transformation_facade.h"
 #include "support/xerces_string_guard.h"
 #include "support/dom/result_node_facade.h"
@@ -14,13 +16,13 @@ xercesc::DOMDocument* FunctionTransform::constructDocument(
 	const InputXSLT::FilesystemContext& fsContext,
 	const FunctionBase::parameter_tuple& parameters
 ) {
-	const std::string transformationPath(
+	const std::string transformationPath(boost::trim_copy(
 		fsContext.resolve(std::get<0>(parameters)).string()
-	);
+	));
 
-	const std::string targetPath(
+	const std::string targetPath(boost::trim_copy(
 		fsContext.resolve(std::get<1>(parameters)).string()
-	);
+	));
 
 	const xalan::XObjectPtr& parameterObject(
 		std::get<2>(parameters)
diff --git a/src/support/error_handler.cc b/src/support/error_handler.cc
new file mode 100644
index 0000000..9a898a6
--- /dev/null
+++ b/src/support/error_handler.cc
@@ -0,0 +1,43 @@
+#include "error_handler.h"
+
+#include <xercesc/sax/SAXParseException.hpp>
+
+#include <iostream>
+
+#include "support/xerces_string_guard.h"
+
+namespace InputXSLT {
+
+ErrorHandler::ErrorHandler(const std::string& transformation):
+	transformation_path_(transformation) { }
+
+void ErrorHandler::warning(const xercesc::SAXParseException& e) {
+	std::cerr << "Warning in "
+	          << "'"
+	          << this->transformation_path_
+	          << "': "
+	          << *XercesStringGuard<char>(e.getMessage())
+	          << std::endl;
+}
+
+void ErrorHandler::error(const xercesc::SAXParseException& e) {
+	std::cerr << "Error in "
+	          << "'"
+	          << this->transformation_path_
+	          << "': "
+	          << *XercesStringGuard<char>(e.getMessage())
+	          << std::endl;
+}
+
+void ErrorHandler::fatalError(const xercesc::SAXParseException& e) {
+	std::cerr << "Fatal error in "
+	          << "'"
+	          << this->transformation_path_
+	          << "': "
+	          << *XercesStringGuard<char>(e.getMessage())
+	          << std::endl;
+}
+
+void ErrorHandler::resetErrors() { }
+
+}
diff --git a/src/support/error_handler.h b/src/support/error_handler.h
new file mode 100644
index 0000000..7835292
--- /dev/null
+++ b/src/support/error_handler.h
@@ -0,0 +1,26 @@
+#ifndef INPUTXSLT_SRC_SUPPORT_ERROR_HANDLER_H_
+#define INPUTXSLT_SRC_SUPPORT_ERROR_HANDLER_H_
+
+#include <xercesc/sax/ErrorHandler.hpp>
+
+#include <string>
+
+namespace InputXSLT {
+
+class ErrorHandler : public xercesc::ErrorHandler {
+	public:
+		ErrorHandler(const std::string&);
+
+		virtual void warning(const xercesc::SAXParseException&);
+		virtual void error(const xercesc::SAXParseException&);
+		virtual void fatalError(const xercesc::SAXParseException&);
+		virtual void resetErrors();
+
+	private:
+		const std::string& transformation_path_;
+
+};
+
+}
+
+#endif  // INPUTXSLT_SRC_SUPPORT_ERROR_HANDLER_H_
diff --git a/src/transformation_facade.cc b/src/transformation_facade.cc
index 3bf1532..fc7e1de 100644
--- a/src/transformation_facade.cc
+++ b/src/transformation_facade.cc
@@ -15,8 +15,10 @@ TransformationFacade::TransformationFacade(
 	IncludeEntityResolver* resolver
 ):
 	transformation_{},
-	transformer_() {
+	transformer_(),
+	error_handler_(transformation) {
 	this->transformer_.setEntityResolver(resolver);
+	this->transformer_.setErrorHandler(&this->error_handler_);
 
 	this->transformer_.compileStylesheet(
 		xalan::XSLTInputSource(transformation.data()),
diff --git a/src/transformation_facade.h b/src/transformation_facade.h
index 1e09248..ab76cac 100644
--- a/src/transformation_facade.h
+++ b/src/transformation_facade.h
@@ -6,6 +6,7 @@
 #include <string>
 
 #include "common.h"
+#include "support/error_handler.h"
 #include "support/include_entity_resolver.h"
 #include "support/stylesheet_parameter_guard.h"
 
@@ -29,6 +30,7 @@ class TransformationFacade {
 		const xalan::XalanCompiledStylesheet* transformation_;
 
 		xalan::XalanTransformer transformer_;
+		ErrorHandler error_handler_;
 
 		int generate(const std::string&, StylesheetParameterGuard&);
 		int generate(std::basic_ostream<char>&, StylesheetParameterGuard&);