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

2 files changed, 69 insertions, 0 deletions

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_