Added context awareness to XObjectValue casting logic

* added support for defining boost::filesystem::path as a external function parameter
** boost::filesystem::path parameters are resolved against the appropriate FilesystemContext and IncludeEntityResolver instances
* xalan::XSLTInputSource parameter source paths are also resolved
* removed need for passing a reference FilesystemContext to "constructDocument" methods
** they now only accept the parameters of the external function implemented by them
** all path resolution logic is wrapped by the newly created XObjectValue class
* converted XObjectValue namespace into class
** the "get" template method is now a template member method
** this was needed to enable value casting logic to access the appropriate FilesystemContext and IncludeEntityResolver instances
* this commit marks the next step towards the goals defined in 741a70f

1 files changed, 8 insertions, 6 deletions

diff --git a/src/function/base.h b/src/function/base.h
index 5212d65..5aada0e 100644
--- a/src/function/base.h
+++ b/src/function/base.h
@@ -96,16 +96,18 @@ class FunctionBase : public xalan::Function {
 			const xalan::Locator* locator,
 			Sequence<Index...>
 		) const {
+			XObjectValue valueGetter(
+				this->include_resolver_->resolve(
+					locator->getSystemId()
+				),
+				this->include_resolver_
+			);
+
 			return this->document_cache_->create(
 				static_cast<Implementation*>(
 					const_cast<FunctionBase*>(this)
 				)->constructDocument(
-					FilesystemContext(
-						this->include_resolver_->resolve(
-							locator->getSystemId()
-						)
-					),
-					XObjectValue::get<typename std::tuple_element<
+					valueGetter.get<typename std::tuple_element<
 						Index,
 						std::tuple<Types...>
 					>::type>(parameters[Index])...