Support for plugable error handlers

8 files changed, 218 insertions, 18 deletions

diff --git a/icespider/core/core.cpp b/icespider/core/core.cpp
index 9d187c9..3b3ec06 100644
--- a/icespider/core/core.cpp
+++ b/icespider/core/core.cpp
@@ -6,6 +6,7 @@
 #include <factory.impl.h>
 
 INSTANTIATEFACTORY(IceSpider::Plugin, Ice::CommunicatorPtr, Ice::PropertiesPtr);
+INSTANTIATEPLUGINOF(IceSpider::ErrorHandler);
 
 namespace IceSpider {
 	const boost::filesystem::path Core::defaultConfig("config/ice.properties");
@@ -69,13 +70,40 @@ namespace IceSpider {
 			request->response(he.code, he.message);
 		}
 		catch (const std::exception & e) {
-			request->response(500, e.what());
+			handleError(request, e);
 		}
 		catch (...) {
 			request->response(500, "Unknown internal server error");
 		}
 	}
 
+	void
+	Core::handleError(IHttpRequest * request, const std::exception & exception) const
+	{
+		auto errorHandlers = AdHoc::PluginManager::getDefault()->getAll<ErrorHandler>();
+		for (const auto & eh : errorHandlers) {
+			try {
+				switch (eh->implementation()->handleError(request, exception)) {
+					case ErrorHandlerResult_Handled:
+						return;
+					case ErrorHandlerResult_Unhandled:
+						continue;
+					case ErrorHandlerResult_Modified:
+						process(request, nullptr);
+						return;
+				}
+			}
+			catch (const HttpException & he) {
+				request->response(he.code, he.message);
+				return;
+			}
+			catch (...) {
+				std::cerr << "Error handler failed" << std::endl;
+			}
+		}
+		request->response(500, exception.what());
+	}
+
 	Ice::ObjectPrx
 	Core::getProxy(const char * type) const
 	{
diff --git a/icespider/core/core.h b/icespider/core/core.h
index b1ea594..a5de08a 100644
--- a/icespider/core/core.h
+++ b/icespider/core/core.h
@@ -18,6 +18,7 @@ namespace IceSpider {
 
 			virtual const IRouteHandler * findRoute(const IHttpRequest *) const = 0;
 			void process(IHttpRequest *, const IRouteHandler * = nullptr) const;
+			void handleError(IHttpRequest *, const std::exception &) const;
 
 			Ice::ObjectPrx getProxy(const char * type) const;
 
@@ -49,6 +50,17 @@ namespace IceSpider {
 	class DLL_PUBLIC Plugin : public virtual Ice::Object {
 	};
 	typedef AdHoc::Factory<Plugin, Ice::CommunicatorPtr, Ice::PropertiesPtr> PluginFactory;
+
+	enum ErrorHandlerResult {
+		ErrorHandlerResult_Unhandled,
+		ErrorHandlerResult_Handled,
+		ErrorHandlerResult_Modified,
+	};
+	class DLL_PUBLIC ErrorHandler : public AdHoc::AbstractPluginImplementation {
+		public:
+			virtual ErrorHandlerResult handleError(IHttpRequest * IHttpRequest, const std::exception &) const = 0;
+	};
+	typedef AdHoc::PluginOf<ErrorHandler> ErrorHandlerPlugin;
 }
 
 #endif
diff --git a/icespider/core/ihttpRequest.h b/icespider/core/ihttpRequest.h
index d92d549..b22406d 100644
--- a/icespider/core/ihttpRequest.h
+++ b/icespider/core/ihttpRequest.h
@@ -24,6 +24,7 @@ namespace IceSpider {
 
 			Ice::Context getContext() const;
 			virtual const PathElements & getRequestPath() const = 0;
+			virtual PathElements & getRequestPath() = 0;
 			virtual HttpMethod getRequestMethod() const = 0;
 
 			const std::string & getURLParam(unsigned int) const;
@@ -31,6 +32,10 @@ namespace IceSpider {
 			virtual OptionalString getHeaderParam(const std::string &) const = 0;
 			virtual OptionalString getCookieParam(const std::string &) const = 0;
 			virtual OptionalString getEnv(const std::string &) const = 0;
+			virtual void setQueryStringParam(const std::string &, const OptionalString &) = 0;
+			virtual void setHeaderParam(const std::string &, const OptionalString &) = 0;
+			virtual void setCookieParam(const std::string &, const OptionalString &) = 0;
+			virtual void setEnv(const std::string &, const OptionalString &) = 0;
 			virtual Slicer::DeserializerPtr getDeserializer() const;
 			virtual ContentTypeSerializer getSerializer(const IRouteHandler *) const;
 			virtual std::istream & getInputStream() const = 0;
diff --git a/icespider/fcgi/cgiRequestBase.cpp b/icespider/fcgi/cgiRequestBase.cpp
index e820e05..f99bbf1 100644
--- a/icespider/fcgi/cgiRequestBase.cpp
+++ b/icespider/fcgi/cgiRequestBase.cpp
@@ -85,6 +85,12 @@ namespace IceSpider {
 		return pathElements;
 	}
 
+	PathElements &
+	CgiRequestBase::getRequestPath()
+	{
+		return pathElements;
+	}
+
 	HttpMethod
 	CgiRequestBase::getRequestMethod() const
 	{
@@ -121,6 +127,36 @@ namespace IceSpider {
 		return optionalLookup(("HTTP_" + boost::algorithm::to_upper_copy(key)).c_str(), envmap);
 	}
 
+	void
+	CgiRequestBase::setQueryStringParam(const std::string & key, const OptionalString & val)
+	{
+		if (val)
+			qsmap[key] = val;
+		else
+			qsmap.erase(key);
+	}
+
+	void
+	CgiRequestBase::setHeaderParam(const std::string &, const OptionalString &)
+	{
+		throw std::runtime_error("Changing the CGI environment is not supported.");
+	}
+
+	void
+	CgiRequestBase::setCookieParam(const std::string & key, const OptionalString & val)
+	{
+		if (val)
+			cookiemap[key] = val;
+		else
+			cookiemap.erase(key);
+	}
+
+	void
+	CgiRequestBase::setEnv(const std::string &, const OptionalString &)
+	{
+		throw std::runtime_error("Changing the CGI environment is not supported.");
+	}
+
 	void CgiRequestBase::response(short statusCode, const std::string & statusMsg) const
 	{
 		getOutputStream()
diff --git a/icespider/fcgi/cgiRequestBase.h b/icespider/fcgi/cgiRequestBase.h
index ec3d4dd..a7cc27d 100644
--- a/icespider/fcgi/cgiRequestBase.h
+++ b/icespider/fcgi/cgiRequestBase.h
@@ -22,11 +22,16 @@ namespace IceSpider {
 			typedef std::map<const char *, Env, cmp_str> VarMap;
 
 			const PathElements & getRequestPath() const override;
+			PathElements & getRequestPath() override;
 			HttpMethod getRequestMethod() const override;
 			OptionalString getQueryStringParam(const std::string & key) const override;
 			OptionalString getHeaderParam(const std::string & key) const override;
 			OptionalString getCookieParam(const std::string & key) const override;
 			OptionalString getEnv(const std::string & key) const override;
+			void setQueryStringParam(const std::string &, const OptionalString &) override;
+			void setHeaderParam(const std::string &, const OptionalString &) override;
+			void setCookieParam(const std::string &, const OptionalString &) override;
+			void setEnv(const std::string &, const OptionalString &) override;
 
 			void response(short, const std::string &) const override;
 			void setHeader(const std::string &, const std::string &) const override;
diff --git a/icespider/testing/testRequest.cpp b/icespider/testing/testRequest.cpp
index 1645445..daecc49 100644
--- a/icespider/testing/testRequest.cpp
+++ b/icespider/testing/testRequest.cpp
@@ -14,40 +14,89 @@ namespace IceSpider {
 		}
 	}
 
-	const std::vector<std::string> &
+	const PathElements &
 	TestRequest::getRequestPath() const
 	{
 		return url;
 	}
 
+	PathElements &
+	TestRequest::getRequestPath()
+	{
+		return url;
+	}
+
 	HttpMethod
 	TestRequest::getRequestMethod() const
 	{
 		return method;
 	}
 
-	IceUtil::Optional<std::string>
+	OptionalString
 	TestRequest::getEnv(const std::string & key) const
 	{
-		return env.find(key) == env.end() ? IceUtil::Optional<std::string>() : env.find(key)->second;
+		return get(key, env);
 	}
 
-	IceUtil::Optional<std::string>
+	OptionalString
 	TestRequest::getQueryStringParam(const std::string & key) const
 	{
-		return qs.find(key) == qs.end() ? IceUtil::Optional<std::string>() : qs.find(key)->second;
+		return get(key, qs);
 	}
 
-	IceUtil::Optional<std::string>
+	OptionalString
 	TestRequest::getCookieParam(const std::string & key) const
 	{
-		return cookies.find(key) == cookies.end() ? IceUtil::Optional<std::string>() : cookies.find(key)->second;
+		return get(key, cookies);
 	}
 
-	IceUtil::Optional<std::string>
+	OptionalString
 	TestRequest::getHeaderParam(const std::string & key) const
 	{
-		return hdr.find(key) == hdr.end() ? IceUtil::Optional<std::string>() : hdr.find(key)->second;
+		return get(key, hdr);
+	}
+
+	OptionalString
+	TestRequest::get(const std::string & key, const MapVars & vars) const
+	{
+		auto i = vars.find(key);
+		if (i == vars.end()) {
+			return IceUtil::None;
+		}
+		return i->second;
+	}
+
+	void
+	TestRequest::setQueryStringParam(const std::string & key, const OptionalString & val)
+	{
+		set(key, val, qs);
+	}
+
+	void
+	TestRequest::setHeaderParam(const std::string & key, const OptionalString & val)
+	{
+		set(key, val, hdr);
+	}
+		
+	void
+	TestRequest::setCookieParam(const std::string & key, const OptionalString & val)
+	{
+		set(key, val, cookies);
+	}
+
+	void
+	TestRequest::setEnv(const std::string & key, const OptionalString & val)
+	{
+		set(key, val, env);
+	}
+		
+	void
+	TestRequest::set(const std::string & key, const OptionalString & val, MapVars & vars)
+	{
+		if (val)
+			vars[key] = *val;
+		else
+			vars.erase(key);
 	}
 
 	std::istream &
diff --git a/icespider/testing/testRequest.h b/icespider/testing/testRequest.h
index 3fd40f0..3278930 100644
--- a/icespider/testing/testRequest.h
+++ b/icespider/testing/testRequest.h
@@ -8,16 +8,20 @@ namespace IceSpider {
 	class DLL_PUBLIC TestRequest : public IHttpRequest {
 		public:
 			typedef std::map<std::string, std::string> MapVars;
-			typedef std::vector<std::string> UrlVars;
 
 			TestRequest(const Core * c, HttpMethod m, const std::string & p);
 
-			const std::vector<std::string> & getRequestPath() const override;
+			const PathElements & getRequestPath() const override;
+			PathElements & getRequestPath() override;
 			HttpMethod getRequestMethod() const override;
-			IceUtil::Optional<std::string> getEnv(const std::string & key) const override;
-			IceUtil::Optional<std::string> getQueryStringParam(const std::string & key) const override;
-			IceUtil::Optional<std::string> getCookieParam(const std::string & key) const override;
-			IceUtil::Optional<std::string> getHeaderParam(const std::string & key) const override;
+			OptionalString getEnv(const std::string & key) const override;
+			OptionalString getQueryStringParam(const std::string & key) const override;
+			OptionalString getCookieParam(const std::string & key) const override;
+			OptionalString getHeaderParam(const std::string & key) const override;
+			void setQueryStringParam(const std::string &, const OptionalString &) override;
+			void setHeaderParam(const std::string &, const OptionalString &) override;
+			void setCookieParam(const std::string &, const OptionalString &) override;
+			void setEnv(const std::string &, const OptionalString &) override;
 			std::istream & getInputStream() const override;
 			std::ostream & getOutputStream() const override;
 			void response(short statusCode, const std::string & statusMsg) const override;
@@ -25,7 +29,7 @@ namespace IceSpider {
 
 			const MapVars & getResponseHeaders();
 
-			UrlVars url;
+			PathElements url;
 			MapVars qs;
 			MapVars cookies;
 			MapVars hdr;
@@ -34,6 +38,10 @@ namespace IceSpider {
 			mutable std::stringstream output;
 			const HttpMethod method;
 
+		protected:
+			OptionalString get(const std::string &, const MapVars &) const;
+			void set(const std::string &, const OptionalString &, MapVars &);
+
 		private:
 			MapVars responseHeaders;
 	};
diff --git a/icespider/unittests/testApp.cpp b/icespider/unittests/testApp.cpp
index 000f983..7a60875 100644
--- a/icespider/unittests/testApp.cpp
+++ b/icespider/unittests/testApp.cpp
@@ -154,6 +154,9 @@ class TestSerice : public TestIceSpider::TestApi {
 			if (s == "error") {
 				throw TestIceSpider::Ex("test error");
 			}
+			else if (s.length() == 3) {
+				throw TestIceSpider::Ex(s);
+			}
 			BOOST_REQUIRE_EQUAL(s, "some value");
 		}
 
@@ -491,7 +494,31 @@ BOOST_AUTO_TEST_CASE( testCookies )
 	BOOST_REQUIRE_EQUAL(h["Status"], "200 OK");
 }
 
-BOOST_AUTO_TEST_CASE( testErrorHandler )
+class DummyErrorHandler : public IceSpider::ErrorHandler {
+	public:
+		IceSpider::ErrorHandlerResult
+		handleError(IceSpider::IHttpRequest * request, const std::exception & ex) const
+		{
+			if (const auto * tex = dynamic_cast<const TestIceSpider::Ex *>(&ex)) {
+				if (tex->message == "404") {
+					throw IceSpider::Http404_NotFound();
+				}
+				if (tex->message == "304") {
+					request->getRequestPath().front() = "some value";
+					return IceSpider::ErrorHandlerResult_Modified;
+				}
+				if (tex->message == "400") {
+					request->response(400, "Handled");
+					return IceSpider::ErrorHandlerResult_Handled;
+				}
+			}
+			return IceSpider::ErrorHandlerResult_Unhandled;
+		}
+};
+
+PLUGIN(DummyErrorHandler, IceSpider::ErrorHandler);
+
+BOOST_AUTO_TEST_CASE( testErrorHandler_Unhandled )
 {
 	TestRequest requestDeleteItem(this, HttpMethod::DELETE, "/error");
 	process(&requestDeleteItem);
@@ -501,5 +528,35 @@ BOOST_AUTO_TEST_CASE( testErrorHandler )
 	BOOST_REQUIRE(requestDeleteItem.output.eof());
 }
 
+BOOST_AUTO_TEST_CASE( testErrorHandler_Handled1 )
+{
+	TestRequest requestDeleteItem(this, HttpMethod::DELETE, "/404");
+	process(&requestDeleteItem);
+	auto h = requestDeleteItem.getResponseHeaders();
+	BOOST_REQUIRE_EQUAL(h["Status"], "404 Not found");
+	requestDeleteItem.output.get();
+	BOOST_REQUIRE(requestDeleteItem.output.eof());
+}
+
+BOOST_AUTO_TEST_CASE( testErrorHandler_Handled2 )
+{
+	TestRequest requestDeleteItem(this, HttpMethod::DELETE, "/400");
+	process(&requestDeleteItem);
+	auto h = requestDeleteItem.getResponseHeaders();
+	BOOST_REQUIRE_EQUAL(h["Status"], "400 Handled");
+	requestDeleteItem.output.get();
+	BOOST_REQUIRE(requestDeleteItem.output.eof());
+}
+
+BOOST_AUTO_TEST_CASE( testErrorHandler_Handled3 )
+{
+	TestRequest requestDeleteItem(this, HttpMethod::DELETE, "/304");
+	process(&requestDeleteItem);
+	auto h = requestDeleteItem.getResponseHeaders();
+	BOOST_REQUIRE_EQUAL(h["Status"], "200 OK");
+	requestDeleteItem.output.get();
+	BOOST_REQUIRE(requestDeleteItem.output.eof());
+}
+
 BOOST_AUTO_TEST_SUITE_END();