Added XercesStringGuard scope-guard to manage XMLCh

* xercesc requires XMLCh* strings to be hand-allocated and released using the XMLString class
* XercesStringGuard works as a scope-guard for XMLCh* string lifetime and greatly simplifies xerces DOM construction

2 files changed, 42 insertions, 0 deletions

diff --git a/src/support/xerces_string_guard.cc b/src/support/xerces_string_guard.cc
new file mode 100644
index 0000000..14ad29b
--- /dev/null
+++ b/src/support/xerces_string_guard.cc
@@ -0,0 +1,18 @@
+#include "xerces_string_guard.h"
+
+namespace InputXSLT {
+
+XercesStringGuard::XercesStringGuard(const std::string& src):
+	string_(xercesc::XMLString::transcode(src.data())) { }
+
+XercesStringGuard::~XercesStringGuard() {
+	xercesc::XMLString::release(
+		const_cast<XMLCh**>(&this->string_)
+	);
+}
+
+XMLCh* XercesStringGuard::operator*() {
+	return this->string_;
+}
+
+}
diff --git a/src/support/xerces_string_guard.h b/src/support/xerces_string_guard.h
new file mode 100644
index 0000000..f64a53e
--- /dev/null
+++ b/src/support/xerces_string_guard.h
@@ -0,0 +1,24 @@
+#ifndef INPUTXSLT_SRC_SUPPORT_XERCES_STRING_GUARD_H_
+#define INPUTXSLT_SRC_SUPPORT_XERCES_STRING_GUARD_H_
+
+#include <xercesc/util/XMLString.hpp>
+
+#include <string>
+
+namespace InputXSLT {
+
+class XercesStringGuard {
+	public:
+		XercesStringGuard(const std::string&);
+		~XercesStringGuard();
+
+		XMLCh* operator*();
+
+	private:
+		XMLCh* const string_;
+
+};
+
+}
+
+#endif  // INPUTXSLT_SRC_SUPPORT_XERCES_STRING_GUARD_H_