Implemented basic external transform function

* "InputXSLT:transform" expects two input arguments and executes the given transformation into the given target file
** this function respresents a important step in the direction of making it possible to write an actual static site generator on top of InputXSLT using XSLT
* added basic "transform" test case
* updated README.md to include this new function

1 files changed, 43 insertions, 0 deletions

diff --git a/src/function/transform.h b/src/function/transform.h
new file mode 100644
index 0000000..41bba05
--- /dev/null
+++ b/src/function/transform.h
@@ -0,0 +1,43 @@
+#ifndef INPUTXSLT_SRC_FUNCTION_TRANSFORM_H_
+#define INPUTXSLT_SRC_FUNCTION_TRANSFORM_H_
+
+#include <xalanc/XalanTransformer/XalanTransformer.hpp>
+#include <xalanc/XPath/XObjectFactory.hpp>
+#include <xalanc/XPath/Function.hpp>
+#include <xalanc/XPath/XObject.hpp>
+
+#include <memory>
+
+#include "common.h"
+#include "support/dom/document_cache.h"
+#include "support/filesystem_context.h"
+
+namespace InputXSLT {
+
+class FunctionTransform : public xalan::Function {
+	public:
+		FunctionTransform();
+
+		virtual xalan::XObjectPtr execute(
+			xalan::XPathExecutionContext&,
+			xalan::XalanNode*,
+			const xalan::XObjectPtr,
+			const xalan::XObjectPtr,
+			const xalan::Locator*
+		) const;
+
+		virtual FunctionTransform* clone(xalan::MemoryManager&) const;
+
+		FunctionTransform& operator=(const FunctionTransform&) = delete;
+		bool operator==(const FunctionTransform&) const        = delete;
+
+	private:
+		std::shared_ptr<DomDocumentCache> document_cache_;
+
+		const xalan::XalanDOMString& getError(xalan::XalanDOMString&) const;
+
+};
+
+}
+
+#endif  // INPUTXSLT_SRC_FUNCTION_TRANSFORM_H_