Adds a presenter loader that performs basic HTTP content negotiation

5 files changed, 76 insertions, 3 deletions

diff --git a/project2/cgi/cgiContentNegotiate.cpp b/project2/cgi/cgiContentNegotiate.cpp
new file mode 100644
index 0000000..8e265a8
--- /dev/null
+++ b/project2/cgi/cgiContentNegotiate.cpp
@@ -0,0 +1,57 @@
+#include <pch.hpp>
+#include "cgiAppEngine.h"
+#include <boost/tokenizer.hpp>
+
+class ContentNegotiateLoader : public PresenterLoader {
+	public:
+		ContentNegotiateLoader() :
+			opts("Content negotiation options")
+		{
+			opts
+				("cgi.contentnegotiation.mappedtype", Options::value(&mappedTypes),
+				 "mimetype=presenter list of types to negotiate")
+				;
+		}
+		
+		const Options * options() const { return &opts; }
+
+		MultiRowSetPresenter * create(const ScriptNodePtr & s, const ObjectSource & os) const
+		{
+			auto accept = static_cast<const CgiApplicationEngine *>(CgiApplicationEngine::getCurrent())->env()->getAccept();
+			typedef boost::tokenizer<boost::char_separator<char>> tokenizer;
+			BOOST_FOREACH(auto mimetypeAndWeight, tokenizer(accept, boost::char_separator<char>(","))) {
+				const auto mimetype = mimetypeAndWeight.substr(0, mimetypeAndWeight.find(';'));
+				if (mimetype == "*/*") break;
+				BOOST_FOREACH(const auto & t, mappedTypes) {
+					if (t.Matches(mimetype)) {
+						return PresenterLoader::getFor(t.present)->create(s, os);
+					}
+				}
+			}
+			return PresenterLoader::getFor(mappedTypes.begin()->present)->create(s, os);
+		}
+
+		Options opts;
+		class MappedType {
+			public:
+				MappedType(const std::string & val) :
+					accept(val.substr(0, val.find('='))),
+					present(val.substr(val.find('=') + 1))
+				{
+				}
+
+				bool Matches(const std::string & a) const
+				{
+					return (accept == a);
+				}
+
+				const std::string accept;
+				const std::string present;
+		};
+		std::vector<MappedType> mappedTypes;
+
+		bool cacheable() const { return false; }
+};
+
+DECLARE_CUSTOM_COMPONENT_LOADER("contentnegotiate", ContentNegotiateLoader, ContentNegotiateLoader, PresenterLoader);
+
diff --git a/project2/cgi/cgiEnvironment.cpp b/project2/cgi/cgiEnvironment.cpp
index 292a52f..c106f67 100644
--- a/project2/cgi/cgiEnvironment.cpp
+++ b/project2/cgi/cgiEnvironment.cpp
@@ -30,7 +30,7 @@ CgiEnvironment::CgiEnvironment() :
 		 "The folder in which to find request scripts")
 		("cgi.errorPresentRoot", Options::value(&errorPresentRoot, "error"),
 		 "The folder in which to find presentation scripts for error handling")
-		("cgi.errorContentType", Options::value(&errorContentType, "text/xml"),
+		("cgi.errorContentType", Options::value(&errorContentType, "application/xml"),
 		 "The Content-Type to use in HTTP headers in event of an error")
 		("cgi.errorTransformStyle", Options::value(&errorTransformStyle),
 		 "The xml-stylesheet to specify in the data document in event of an error")
@@ -101,6 +101,12 @@ CgiEnvironment::getServerName() const
 	return cgi->getEnvironment().getServerName();
 }
 
+std::string
+CgiEnvironment::getAccept() const
+{
+	return cgi->getEnvironment().getAccept();
+}
+
 const Glib::ustring &
 CgiEnvironment::platform() const
 {
diff --git a/project2/cgi/cgiEnvironment.h b/project2/cgi/cgiEnvironment.h
index dd89a75..330cd97 100644
--- a/project2/cgi/cgiEnvironment.h
+++ b/project2/cgi/cgiEnvironment.h
@@ -42,6 +42,7 @@ class CgiEnvironment : public Environment {
 		std::string getScriptName() const;
 		std::string getRedirectURL() const;
 		std::string getRequestMethod() const;
+		std::string getAccept() const;
 		ETags getRequestETags() const;
 		time_t getRequestModifiedSince() const;
 		std::string getCookieValue(const std::string & name) const;
diff --git a/project2/common/options.h b/project2/common/options.h
index a28b5f8..93c6aa5 100644
--- a/project2/common/options.h
+++ b/project2/common/options.h
@@ -99,10 +99,19 @@ class Options {
 					target->clear();
 				}
 				void assign(const Glib::ustring & value) const {
-					target->push_back(boost::lexical_cast<T>(value));
+					doAssign(value);
 				}
 			protected:
 				VofT * target;
+			private:
+				template <typename dummy = int>
+				void doAssign(const Glib::ustring & value, typename boost::disable_if<std::is_constructible<T, Glib::ustring>, dummy>::type = 0) const {
+					target->push_back(boost::lexical_cast<T>(value));
+				}
+				template <typename dummy = int>
+				void doAssign(const Glib::ustring & value, typename boost::enable_if<std::is_constructible<T, Glib::ustring>, dummy>::type = 0) const {
+					target->push_back(T(value));
+				}
 		};
 
 		class Option : public IntrusivePtrBase {
diff --git a/project2/xml/xmlPresenter.cpp b/project2/xml/xmlPresenter.cpp
index 45836a2..ddb1e03 100644
--- a/project2/xml/xmlPresenter.cpp
+++ b/project2/xml/xmlPresenter.cpp
@@ -77,7 +77,7 @@ XmlPresenter::XmlPresenter(const Glib::ustring & responseRootNodeName, const Gli
 XmlPresenter::XmlPresenter(ScriptNodePtr e, ObjectSource os) :
 	TransformSource(e, os),
 	Presenter(os),
-	ContentPresenter(e->value("contenttype", "text/xml")),
+	ContentPresenter(e->value("contenttype", "application/xml")),
 	SourceOf<xmlpp::Document>(e, os),
 	SourceOf<_xmlDoc>(e, os),
 	SourceOf<boost::shared_ptr<xmlpp::Document> >(e, os),