Massive refactor to remove the appEngine and environment complication and instead have an execution context that's passed around from the original call site

75 files changed, 372 insertions, 450 deletions

diff --git a/project2/common/aggregate.cpp b/project2/common/aggregate.cpp
index 1bb453b..ee7c871 100644
--- a/project2/common/aggregate.cpp
+++ b/project2/common/aggregate.cpp
@@ -17,8 +17,8 @@ SetAggregate::SetAggregate(ScriptNodePtr s) :
 }
 
 void
-Aggregate::pushValue() const
+Aggregate::pushValue(ExecContext * ec) const
 {
-	pushValue(value());
+	pushValue(value(ec), ec);
 }
 
diff --git a/project2/common/aggregate.h b/project2/common/aggregate.h
index 0641c6e..7f33b6b 100644
--- a/project2/common/aggregate.h
+++ b/project2/common/aggregate.h
@@ -10,9 +10,9 @@ class Aggregate : public SourceObject {
 		Aggregate(ScriptNodePtr);
 
 		virtual void reset() const = 0;
-		void pushValue() const;
+		void pushValue(ExecContext * ec) const;
 	protected:
-		virtual void pushValue(const VariableType &) const = 0;
+		virtual void pushValue(const VariableType &, ExecContext *) const = 0;
 	private:
 		Variable value;
 };
diff --git a/project2/common/appEngine.cpp b/project2/common/appEngine.cpp
deleted file mode 100644
index ce71153..0000000
--- a/project2/common/appEngine.cpp
+++ /dev/null
@@ -1,53 +0,0 @@
-#include <pch.hpp>
-#include "appEngine.h"
-#include "logger.h"
-#include "presenter.h"
-#include <stdexcept>
-#include <boost/foreach.hpp>
-
-ApplicationEngine * ApplicationEngine::currentEngine = NULL;
-
-ApplicationEngine::ApplicationEngine()
-{
-	if (currentEngine) {
-		throw std::runtime_error("One application at a time, please");
-	}
-	currentEngine = this;
-}
-
-ApplicationEngine::~ApplicationEngine()
-{
-	currentEngine = NULL;
-}
-
-void
-ApplicationEngine::logMessage(bool writeLog, const Glib::ustring & g, const Glib::ustring & m)
-{
-	if (writeLog) {
-		Logger()->messagebf(LOG_NOTICE, "%s: %s: %s", __PRETTY_FUNCTION__, g, m);
-	}
-	appMessages.push_back(new Message(g, m));
-}
-
-void
-ApplicationEngine::addCoreAppData(const MultiRowSetPresenter * p) const
-{
-	// Message log
-	p->addNewRowSet("messages", Scripts::scriptNamespacePrefix);
-	p->addNewArray("message", true);
-	BOOST_FOREACH(const Messages::value_type & m, appMessages) {
-		p->addNewRow("message");
-		p->addAttribute("group", m->group);
-		p->addAttribute("text", m->message);
-		p->finishRow();
-	}
-	p->finishArray(true);
-	p->finishRowSet();
-}
-
-ApplicationEngine::Message::Message(const Glib::ustring & g, const Glib::ustring & m) :
-	group(g),
-	message(m)
-{
-}
-
diff --git a/project2/common/appEngine.h b/project2/common/appEngine.h
deleted file mode 100644
index 6de21e1..0000000
--- a/project2/common/appEngine.h
+++ /dev/null
@@ -1,42 +0,0 @@
-#ifndef APPENGINE_H
-#define APPENGINE_H
-
-#include "environment.h"
-#include "session.h"
-
-class MultiRowSetPresenter;
-
-class ApplicationEngine {
-	public:
-		class Message : public IntrusivePtrBase {
-			public:
-				Message(const Glib::ustring & g, const Glib::ustring & m);
-
-				const Glib::ustring group;
-				const Glib::ustring message;
-		};
-		typedef boost::intrusive_ptr<Message> MessagePtr;
-		typedef std::list<MessagePtr> Messages;
-
-		ApplicationEngine();
-		virtual ~ApplicationEngine() = 0;
-
-		void logMessage(bool writeLog, const Glib::ustring & g, const Glib::ustring & m);
-
-		virtual void process() const = 0;
-		virtual const Environment * env() const = 0;
-		virtual SessionPtr session() const = 0;
-
-		static ApplicationEngine * getCurrent() { return currentEngine; }
-
-	protected:
-		void addCoreAppData(const MultiRowSetPresenter * p) const;
-
-		Messages appMessages;
-
-	private:
-		static ApplicationEngine * currentEngine;
-};
-
-#endif
-
diff --git a/project2/common/cache.cpp b/project2/common/cache.cpp
index 9be5845..2a1d410 100644
--- a/project2/common/cache.cpp
+++ b/project2/common/cache.cpp
@@ -9,17 +9,17 @@
 Cache::Cache(ScriptNodePtr p) :
 	IHaveParameters(p),
 	SourceObject(p),
-	inherit(p->value("inherit", true).as<bool>())
+	inherit(p->value("inherit", true, NULL).as<bool>())
 {
 }
 
-bool Cache::checkAndExecute(const Glib::ustring & n, const Glib::ustring & f, const RowProcessor * rp)
+bool Cache::checkAndExecute(ExecContext * ec, const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * p, const RowProcessorCallback & rp)
 {
-	RowSetCPtr cached = getCachedRowSet(n, f, rp);
+	RowSetCPtr cached = getCachedRowSet(ec, n, f, p);
 	if (cached) {
 		try {
 			Logger()->messagebf(LOG_DEBUG, "Executing from cache '%s'", name);
-			cached->execute(f, rp);
+			cached->execute(f, rp, ec);
 			return true;
 		}
 		catch (const Glib::Exception & e) {
@@ -36,14 +36,14 @@ bool Cache::checkAndExecute(const Glib::ustring & n, const Glib::ustring & f, co
 }
 
 void
-Cache::applyKeys(const boost::function2<void, const std::string &, const VariableType &> & f, const IHaveParameters * ps) const
+Cache::applyKeys(ExecContext * ec, const KeyApplier & f, const IHaveParameters * ps) const
 {
 	BOOST_FOREACH(const IHaveParameters::Parameters::value_type & p, allParameters()) {
-		f(p.first, p.second);
+		f(p.first, p.second(ec));
 	}
 	if (inherit) {
 		BOOST_FOREACH(const IHaveParameters::Parameters::value_type & p, ps->allParameters()) {
-			f(p.first, p.second);
+			f(p.first, p.second(ec));
 		}
 	}
 }
diff --git a/project2/common/cache.h b/project2/common/cache.h
index 2c438b8..0806c6f 100644
--- a/project2/common/cache.h
+++ b/project2/common/cache.h
@@ -4,8 +4,8 @@
 #include "sourceObject.h"
 #include "presenter.h"
 #include "iHaveParameters.h"
+#include "rowSet.h"
 
-class RowProcessor;
 class RowSet;
 class RowState;
 typedef boost::intrusive_ptr<const RowSet> RowSetCPtr;
@@ -14,14 +14,15 @@ class Cache : public IHaveParameters, public SourceObject {
 	public:
 		Cache(ScriptNodePtr p);
 
-		bool checkAndExecute(const Glib::ustring &, const Glib::ustring &, const RowProcessor *);
-		virtual RowSetPresenterPtr openFor(const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) = 0;
-		virtual void save(const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) = 0;
-		virtual void discard(const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) = 0;
+		bool checkAndExecute(ExecContext *, const Glib::ustring &, const Glib::ustring &, const IHaveParameters *, const RowProcessorCallback &);
+		virtual RowSetPresenterPtr openFor(ExecContext *, const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) = 0;
+		virtual void save(ExecContext *, const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) = 0;
+		virtual void discard(ExecContext *, const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) = 0;
 
 	protected:
-		virtual RowSetCPtr getCachedRowSet(const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) const = 0;
-		void applyKeys(const boost::function2<void, const std::string &, const VariableType &> & f, const IHaveParameters *) const;
+		virtual RowSetCPtr getCachedRowSet(ExecContext *, const Glib::ustring &, const Glib::ustring &, const IHaveParameters *) const = 0;
+		typedef boost::function<void (const std::string &, const VariableType &)> KeyApplier;
+		void applyKeys(ExecContext * ec, const KeyApplier & f, const IHaveParameters * ps) const;
 		const bool inherit;
 };
 typedef boost::intrusive_ptr<Cache> CachePtr;
diff --git a/project2/common/check.cpp b/project2/common/check.cpp
index 21d17cf..d288e2f 100644
--- a/project2/common/check.cpp
+++ b/project2/common/check.cpp
@@ -20,11 +20,11 @@ Check::~Check()
 }
 
 bool
-Check::performCheck() const
+Check::performCheck(ExecContext * ec) const
 {
 	if (!test) {
 		throw NoTestsToPerform();
 	}
-	return test->passes();
+	return test->passes(ec);
 }
 
diff --git a/project2/common/check.h b/project2/common/check.h
index e9f44b5..dc97f8f 100644
--- a/project2/common/check.h
+++ b/project2/common/check.h
@@ -5,13 +5,15 @@
 #include "variables.h"
 #include "test.h"
 
+class ExecContext;
+
 /// Base class for Project2 compoments that perform checks
 class Check : public SourceObject {
 	public:
 		Check(ScriptNodePtr p);
 		virtual ~Check();
 
-		bool performCheck() const;
+		bool performCheck(ExecContext *) const;
 
 		const Variable message;
 		const Variable group;
diff --git a/project2/common/checkHost.cpp b/project2/common/checkHost.cpp
index 49533a9..dedea85 100644
--- a/project2/common/checkHost.cpp
+++ b/project2/common/checkHost.cpp
@@ -1,6 +1,6 @@
 #include <pch.hpp>
 #include "checkHost.h"
-#include "appEngine.h"
+#include "execContext.h"
 #include <boost/foreach.hpp>
 
 CheckHost::CheckHost(ScriptNodePtr s) :
@@ -14,12 +14,12 @@ CheckHost::~CheckHost()
 }
 
 void
-CheckHost::runChecks() const
+CheckHost::runChecks(ExecContext * ec) const
 {
 	loadScriptComponents();
 	BOOST_FOREACH(const Checks::value_type & pc, checks) {
-		if (!pc->performCheck()) {
-			ApplicationEngine::getCurrent()->logMessage(false, pc->group(), pc->message());
+		if (!pc->performCheck(ec)) {
+			ec->logMessage(false, pc->group(ec), pc->message(ec));
 			throw CheckFailure(pc);
 		}
 	}
diff --git a/project2/common/checkHost.h b/project2/common/checkHost.h
index edc2cd8..f404d9e 100644
--- a/project2/common/checkHost.h
+++ b/project2/common/checkHost.h
@@ -18,7 +18,7 @@ class CheckHost : virtual public CommonObjects {
 		CheckHost(ScriptNodePtr script); 
 		~CheckHost();
 
-		void runChecks() const;
+		void runChecks(ExecContext *) const;
 
 		typedef ANONORDEREDSTORAGEOF(Check) Checks;
 		Checks checks;
diff --git a/project2/common/commonObjects.cpp b/project2/common/commonObjects.cpp
index 23f2edb..a25bb9f 100644
--- a/project2/common/commonObjects.cpp
+++ b/project2/common/commonObjects.cpp
@@ -1,7 +1,6 @@
 #include <pch.hpp>
 #include "commonObjects.h"
 #include "safeMapFind.h"
-#include "appEngine.h"
 #include "scriptLoader.h"
 
 CommonObjects::CommonObjects() :
diff --git a/project2/common/environment.cpp b/project2/common/environment.cpp
deleted file mode 100644
index 69f853c..0000000
--- a/project2/common/environment.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-#include <pch.hpp>
-#include "environment.h"
-#include "optionsSource.h"
-
-const Environment * Environment::currentEnv(NULL);
-
-Environment::Environment()
-{
-	currentEnv = this;
-}
-
-Environment::~Environment()
-{
-	currentEnv = NULL;
-}
-
-const Environment *
-Environment::getCurrent()
-{
-	return currentEnv;
-}
-
diff --git a/project2/common/environment.h b/project2/common/environment.h
deleted file mode 100644
index a97255f..0000000
--- a/project2/common/environment.h
+++ /dev/null
@@ -1,28 +0,0 @@
-#ifndef ENVIRONMENT_H
-#define ENVIRONMENT_H
-
-#include <string>
-#include <glibmm/ustring.h>
-#include "exceptions.h"
-#include "scripts.h"
-
-SimpleMessageException(NoSuchPlatform);
-
-class Environment {
-	public:
-		Environment();
-		virtual ~Environment() = 0;
-
-		static const Environment * getCurrent();
-
-		virtual Glib::ustring getParamQuery(const std::string & idx) const = 0;
-
-		virtual std::string getServerName() const = 0;
-		virtual const Glib::ustring & platform() const = 0;
-
-	private:
-		static const Environment * currentEnv;
-};
-
-#endif
-
diff --git a/project2/common/exceptions.h b/project2/common/exceptions.h
index 38f0efa..9cdf6f0 100644
--- a/project2/common/exceptions.h
+++ b/project2/common/exceptions.h
@@ -67,6 +67,7 @@ SimpleMessageException(NotSupported);
 SimpleMessageException(FileNotReadable);
 SimpleMessageException(FileNotWritable);
 SimpleMessageException(FilterNotFound);
+SimpleMessageException(NoSuchPlatform);
 
 #endif
 
diff --git a/project2/common/execContext.cpp b/project2/common/execContext.cpp
new file mode 100644
index 0000000..571b5f0
--- /dev/null
+++ b/project2/common/execContext.cpp
@@ -0,0 +1,36 @@
+#include "execContext.h"
+#include "logger.h"
+#include "presenter.h"
+#include <boost/foreach.hpp>
+
+void
+ExecContext::logMessage(bool writeLog, const Glib::ustring & g, const Glib::ustring & m)
+{
+	if (writeLog) {
+		Logger()->messagebf(LOG_NOTICE, "%s: %s: %s", __PRETTY_FUNCTION__, g, m);
+	}
+	messages.push_back(new Message(g, m));
+}
+
+void
+ExecContext::addContextData(const MultiRowSetPresenter * p) const
+{
+	// Message log
+	p->addNewRowSet("messages", Scripts::scriptNamespacePrefix);
+	p->addNewArray("message", true);
+	BOOST_FOREACH(const Messages::value_type & m, messages) {
+		p->addNewRow("message");
+		p->addAttribute("group", m->group);
+		p->addAttribute("text", m->message);
+		p->finishRow();
+	}
+	p->finishArray(true);
+	p->finishRowSet();
+}
+
+ExecContext::Message::Message(const Glib::ustring & g, const Glib::ustring & m) :
+	group(g),
+	message(m)
+{
+}
+
diff --git a/project2/common/execContext.h b/project2/common/execContext.h
new file mode 100644
index 0000000..6018058
--- /dev/null
+++ b/project2/common/execContext.h
@@ -0,0 +1,37 @@
+#ifndef EXECCONTEXT_H
+#define EXECCONTEXT_H
+
+#include <glibmm/ustring.h>
+#include <boost/intrusive_ptr.hpp>
+#include <list>
+#include "variableType.h"
+#include "session.h"
+
+class MultiRowSetPresenter;
+
+class ExecContext {
+	public:
+		class Message : public IntrusivePtrBase {
+			public:
+				Message(const Glib::ustring & g, const Glib::ustring & m);
+
+				const Glib::ustring group;
+				const Glib::ustring message;
+		};
+		typedef boost::intrusive_ptr<Message> MessagePtr;
+		typedef std::list<MessagePtr> Messages;
+
+		virtual VariableType getParameter(const VariableType & key) const = 0;
+		virtual SessionPtr getSession() const = 0;
+
+		void logMessage(bool writeLog, const Glib::ustring & g, const Glib::ustring & m);
+		const Messages & getMessages() const;
+
+		void addContextData(const MultiRowSetPresenter * p) const;
+
+	private:
+		Messages messages;
+};
+
+#endif
+
diff --git a/project2/common/iHaveParameters.cpp b/project2/common/iHaveParameters.cpp
index f880944..1bf1362 100644
--- a/project2/common/iHaveParameters.cpp
+++ b/project2/common/iHaveParameters.cpp
@@ -2,7 +2,6 @@
 #include "iHaveParameters.h"
 #include "exceptions.h"
 #include "safeMapFind.h"
-#include "appEngine.h"
 #include <boost/foreach.hpp>
 
 IHaveParameters::Stack IHaveParameters::scope;
@@ -19,9 +18,9 @@ IHaveParameters::~IHaveParameters()
 }
 
 VariableType
-IHaveParameters::getParameter(const Glib::ustring & name) const
+IHaveParameters::getParameter(const Glib::ustring & name, ExecContext * ec) const
 {
-	return safeMapLookup<ParamNotFound>(parameters, name);
+	return safeMapLookup<ParamNotFound>(parameters, name)(ec);
 }
 
 void
@@ -37,12 +36,12 @@ IHaveParameters::pop()
 }
 
 VariableType
-IHaveParameters::getScopedParameter(const Glib::ustring & name)
+IHaveParameters::getScopedParameter(const Glib::ustring & name, ExecContext * ec)
 {
 	for(Stack::const_reverse_iterator ihp = scope.rbegin(); ihp != scope.rend(); ++ihp) {
 		Parameters::const_iterator i = (*ihp)->parameters.find(name);
 		if (i != (*ihp)->parameters.end()) {
-			return i->second;
+			return i->second(ec);
 		}
 	}
 	throw ParamNotFound(name);
diff --git a/project2/common/iHaveParameters.h b/project2/common/iHaveParameters.h
index 2b7ed2a..7b15289 100644
--- a/project2/common/iHaveParameters.h
+++ b/project2/common/iHaveParameters.h
@@ -15,8 +15,8 @@ class IHaveParameters {
 		virtual ~IHaveParameters() = 0;
 
 		const Parameters & allParameters() const;
-		VariableType getParameter(const Glib::ustring &) const;
-		static VariableType getScopedParameter(const Glib::ustring &);
+		VariableType getParameter(const Glib::ustring &, ExecContext *) const;
+		static VariableType getScopedParameter(const Glib::ustring &, ExecContext *);
 
 	protected:
 		Parameters parameters;
diff --git a/project2/common/iHaveSubTasks.cpp b/project2/common/iHaveSubTasks.cpp
index 78868aa..92248fb 100644
--- a/project2/common/iHaveSubTasks.cpp
+++ b/project2/common/iHaveSubTasks.cpp
@@ -13,10 +13,10 @@ IHaveSubTasks::~IHaveSubTasks()
 }
 
 void
-IHaveSubTasks::run(const Tasks & tlist) const
+IHaveSubTasks::run(const Tasks & tlist, ExecContext * ec) const
 {
 	BOOST_FOREACH(const Tasks::value_type & t, tlist) {
-		t->execute();
+		t->execute(ec);
 	}
 }
 
diff --git a/project2/common/iHaveSubTasks.h b/project2/common/iHaveSubTasks.h
index e52a9be..d13a890 100644
--- a/project2/common/iHaveSubTasks.h
+++ b/project2/common/iHaveSubTasks.h
@@ -12,11 +12,11 @@ class IHaveSubTasks : public NoOutputExecute {
 		IHaveSubTasks(const std::string & n);
 		virtual ~IHaveSubTasks();
 
-		virtual void execute() const = 0;
+		virtual void execute(ExecContext * ec) const = 0;
 		Tasks normal;
 
 	protected:
-		void run(const Tasks &) const;
+		void run(const Tasks &, ExecContext * ec) const;
 };
 
 #endif
diff --git a/project2/common/if.cpp b/project2/common/if.cpp
index c7f790e..ed2abf6 100644
--- a/project2/common/if.cpp
+++ b/project2/common/if.cpp
@@ -20,31 +20,31 @@ If::If(ScriptNodePtr e) :
 }
 
 bool
-If::passes() const
+If::passes(ExecContext * ec) const
 {
 	if (!test) {
 		throw NoTestsToPerform();
 	}
-	return test->passes();
+	return test->passes(ec);
 }
 
 void
-If::execute(const MultiRowSetPresenter * presenter) const
+If::execute(const MultiRowSetPresenter * presenter, ExecContext * ec) const
 {
-	if (passes()) {
+	if (passes(ec)) {
 		Logger()->messagef(LOG_DEBUG, "Test passed; showing %zu views", subViews.size());
 		BOOST_FOREACH(const SubViews::value_type & sq, subViews) {
-			sq->execute(presenter);
+			sq->execute(presenter, ec);
 		}
 	}
 }
 
 void
-If::execute() const
+If::execute(ExecContext * ec) const
 {
-	if (passes()) {
+	if (passes(ec)) {
 		Logger()->messagef(LOG_DEBUG, "Test passed; executing %zu tasks", normal.size());
-		run(normal);
+		run(normal, ec);
 	}
 }
 
diff --git a/project2/common/if.h b/project2/common/if.h
index 2496dc4..64f885b 100644
--- a/project2/common/if.h
+++ b/project2/common/if.h
@@ -10,11 +10,11 @@ class If : public IHaveSubTasks, public View {
 	public:
 		If(ScriptNodePtr);
 
-		virtual void execute(const MultiRowSetPresenter*) const;
-		virtual void execute() const;
+		virtual void execute(const MultiRowSetPresenter *, ExecContext *) const;
+		virtual void execute(ExecContext *) const;
 
 	private:
-		bool passes() const;
+		bool passes(ExecContext *) const;
 
 		typedef ANONSTORAGEOF(View) SubViews;
 		SubViews subViews;
diff --git a/project2/common/iterate.cpp b/project2/common/iterate.cpp
index 037261d..4473885 100644
--- a/project2/common/iterate.cpp
+++ b/project2/common/iterate.cpp
@@ -27,22 +27,16 @@ Iterate::loadComplete(const CommonObjects * co)
 }
 
 void
-Iterate::rowReady(const RowState *) const
+Iterate::execute(ExecContext * ec) const
 {
-	executeChildren();
+	RowProcessor::execute(ec, boost::bind(&Iterate::executeChildren, this, ec));
 }
 
 void
-Iterate::execute() const
-{
-	RowProcessor::execute();
-}
-
-void
-Iterate::executeChildren() const
+Iterate::executeChildren(ExecContext * ec) const
 {
 	BOOST_FOREACH(const Tasks::value_type & sq, normal) {
-		sq->execute();
+		sq->execute(ec);
 	}
 }
 
diff --git a/project2/common/iterate.h b/project2/common/iterate.h
index 540cec6..2afbe98 100644
--- a/project2/common/iterate.h
+++ b/project2/common/iterate.h
@@ -15,11 +15,10 @@ class Iterate : public IHaveSubTasks, public RowProcessor {
 		virtual ~Iterate();
 
 		void loadComplete(const CommonObjects *);
-		void rowReady(const RowState *) const;
-		void execute() const;
+		void execute(ExecContext *) const;
 
 	protected:
-		void executeChildren() const;
+		void executeChildren(ExecContext *) const;
 };
 
 #endif
diff --git a/project2/common/library.cpp b/project2/common/library.cpp
index 4762211..738803f 100644
--- a/project2/common/library.cpp
+++ b/project2/common/library.cpp
@@ -11,7 +11,7 @@ SimpleMessageException(UnloadLibraryFailed);
 
 Library::Library(ScriptNodePtr p) :
 	SourceObject(p),
-	handle(dlopen(Variable(p, "path")(), RTLD_NOW))
+	handle(dlopen(Variable(p, "path")(NULL), RTLD_NOW))
 {
 	if (!handle) {
 		throw LoadLibraryFailed(dlerror());
diff --git a/project2/common/memoryCache.cpp b/project2/common/memoryCache.cpp
index 0a4f53f..7ab271e 100644
--- a/project2/common/memoryCache.cpp
+++ b/project2/common/memoryCache.cpp
@@ -43,7 +43,7 @@ class MemoryCache : public Cache {
 				{
 				}
 
-				void execute(const Glib::ustring&, const RowProcessor * rp) const {
+				void execute(const Glib::ustring&, const RowProcessorCallback & rp, ExecContext *) const {
 					BOOST_FOREACH(const DataCache::value_type & mcr, dataCache) {
 						mcr->process(rp, false);
 					}
@@ -100,8 +100,8 @@ class MemoryCache : public Cache {
 		{
 		}
 
-		RowSetCPtr getCachedRowSet(const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * ps) const {
-			Key key(makeKey(n, f, ps));
+		RowSetCPtr getCachedRowSet(ExecContext * ec, const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * ps) const {
+			Key key(makeKey(ec, n, f, ps));
 			CacheStore::index<IndexByKey>::type::const_iterator i = Store.get<IndexByKey>().find(key);
 			if (i == Store.get<IndexByKey>().end()) {
 				return NULL;
@@ -113,27 +113,27 @@ class MemoryCache : public Cache {
 			return *i;
 		}
 
-		RowSetPresenterPtr openFor(const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * ps) {
-			return (cur = new CachedRowSet(makeKey(n, f, ps)));
+		RowSetPresenterPtr openFor(ExecContext * ec, const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * ps) {
+			return (cur = new CachedRowSet(makeKey(ec, n, f, ps)));
 		}
 
-		void save(const Glib::ustring & , const Glib::ustring & , const IHaveParameters * ) {
+		void save(ExecContext *, const Glib::ustring & , const Glib::ustring & , const IHaveParameters * ) {
 			if (cur) {
 				Store.insert(cur);
 				cur.reset();
 			}
 		}
 
-		void discard(const Glib::ustring & , const Glib::ustring & , const IHaveParameters * ) {
+		void discard(ExecContext *, const Glib::ustring & , const Glib::ustring & , const IHaveParameters * ) {
 			cur.reset();
 		}
 
 	private:
-		Key makeKey(const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * ps) const {
+		Key makeKey(ExecContext * ec, const Glib::ustring & n, const Glib::ustring & f, const IHaveParameters * ps) const {
 			Key key;
 			key.push_back(n);
 			key.push_back(f);
-			applyKeys([&key](const std::string &, const VariableType & v) { key.push_back(v); }, ps);
+			applyKeys(ec, [&key](const std::string &, const VariableType & v) { key.push_back(v); }, ps);
 			return key;
 		}
 
diff --git a/project2/common/noOutputExecute.h b/project2/common/noOutputExecute.h
index 67f6b00..61d03b5 100644
--- a/project2/common/noOutputExecute.h
+++ b/project2/common/noOutputExecute.h
@@ -5,6 +5,7 @@
 #include "scriptStorage.h"
 
 class NoOutputExecute;
+class ExecContext;
 typedef boost::intrusive_ptr<NoOutputExecute> NoOutputExecutePtr;
 
 /// Base class for Project2 compoments that perform actions, but product no output
@@ -15,7 +16,7 @@ class NoOutputExecute : public virtual SourceObject {
 
 		virtual ~NoOutputExecute();
 
-		virtual void execute() const = 0;
+		virtual void execute(ExecContext *) const = 0;
 };
 
 #endif
diff --git a/project2/common/options.cpp b/project2/common/options.cpp
index 5c79163..fd93576 100644
--- a/project2/common/options.cpp
+++ b/project2/common/options.cpp
@@ -1,6 +1,5 @@
 #include <pch.hpp>
 #include "options.h"
-#include "environment.h"
 #include <boost/foreach.hpp>
 
 class NamedOption : public Options::Option {
@@ -11,9 +10,9 @@ class NamedOption : public Options::Option {
 			desc(d)
 		{
 		}
-		void consume(const Glib::ustring & n, const Glib::ustring & p, const VariableType & v) const {
+		void consume(const Glib::ustring & n, const Glib::ustring & p, const VariableType & v, const Options::CurrentPlatform & cp) const {
 			if (n == id) {
-				target->consume(p, v);
+				target->consume(p, v, cp);
 			}
 		}
 		void reset() const {
@@ -44,9 +43,9 @@ class OptionAlias : public Options::Option {
 			target(t)
 		{
 		}
-		void consume(const Glib::ustring & a, const Glib::ustring & p, const VariableType & v) const {
+		void consume(const Glib::ustring & a, const Glib::ustring & p, const VariableType & v, const Options::CurrentPlatform & cp) const {
 			if (a == alias) {
-				target->target->consume(p, v);
+				target->target->consume(p, v, cp);
 			}
 		}
 		void reset() const {
@@ -108,10 +107,10 @@ Options::reset() const
 }
 
 void
-Options::consume(const Glib::ustring & n, const Glib::ustring & p, const VariableType & v) const
+Options::consume(const Glib::ustring & n, const Glib::ustring & p, const VariableType & v, const Options::CurrentPlatform & cp) const
 {
 	BOOST_FOREACH(const OptionPtr & o, options) {
-		o->consume(n, p, v);
+		o->consume(n, p, v, cp);
 	}
 }
 
@@ -145,13 +144,13 @@ Options::InstanceTarget::paramRequired() const
 }
 
 void
-Options::InstanceTarget::consume(const Glib::ustring & p, const VariableType & v) const
+Options::InstanceTarget::consume(const Glib::ustring & p, const VariableType & v, const Options::CurrentPlatform & cp) const
 {
 	if (ts != Platform && p.empty()) {
 		assign(v);
 		ts = Global;
 	}
-	else if (!p.empty() && p == Environment::getCurrent()->platform()) {
+	else if (!p.empty() && p == cp) {
 		assign(v);
 		ts = Platform;
 	}
diff --git a/project2/common/options.h b/project2/common/options.h
index e92e69b..c2416ef 100644
--- a/project2/common/options.h
+++ b/project2/common/options.h
@@ -15,11 +15,13 @@ class Options {
 		class Target;
 
 		enum TargetState { Default = 1, Global = 2, Platform = 3 };
+		typedef boost::function<const Glib::ustring &()> CurrentPlatform;
+
 		class Target : public IntrusivePtrBase {
 			public:
 				virtual void reset() const = 0;
 				virtual bool paramRequired() const = 0;
-				virtual void consume(const Glib::ustring & platform, const VariableType & value) const = 0;
+				virtual void consume(const Glib::ustring & platform, const VariableType & value, const CurrentPlatform & currentPlatform) const = 0;
 		};
 		typedef boost::intrusive_ptr<Target> TargetPtr;
 		typedef boost::function<void(const VariableType &)> Assigner;
@@ -29,7 +31,7 @@ class Options {
 			public:
 				InstanceTarget(const Assigner &, const Resetter &);
 				bool paramRequired() const;
-				void consume(const Glib::ustring & platform, const VariableType & value) const;
+				void consume(const Glib::ustring & platform, const VariableType & value, const CurrentPlatform & currentPlatform) const;
 			protected:
 				void reset() const;
 				void assign(const VariableType & value) const;
@@ -45,7 +47,7 @@ class Options {
 				virtual Glib::ustring name() const = 0;
 				virtual Glib::ustring description() const = 0;
 				virtual bool accepts(const Glib::ustring & name) const = 0;
-				virtual void consume(const Glib::ustring & name, const Glib::ustring & platform, const VariableType & value) const = 0;
+				virtual void consume(const Glib::ustring & name, const Glib::ustring & platform, const VariableType & value, const CurrentPlatform & currentPlatform) const = 0;
 		};
 		typedef boost::intrusive_ptr<Option> OptionPtr;
 		typedef std::list<OptionPtr> OptionList;
@@ -86,7 +88,7 @@ class Options {
 		}
 
 		void reset() const;
-		void consume(const Glib::ustring & name, const Glib::ustring & platform, const VariableType & value) const;
+		void consume(const Glib::ustring & name, const Glib::ustring & platform, const VariableType & value, const CurrentPlatform & currentPlatform) const;
 		const Option * find(const Glib::ustring & name) const;
 
 		const Glib::ustring name;
diff --git a/project2/common/optionsSource.cpp b/project2/common/optionsSource.cpp
index ed40df9..702b852 100644
--- a/project2/common/optionsSource.cpp
+++ b/project2/common/optionsSource.cpp
@@ -3,8 +3,8 @@
 
 class DefaultConfigConsumer : public ConfigConsumer {
 	public:
-		void operator()(const Glib::ustring & n, const Glib::ustring & p, const Glib::ustring & v) const {
-			Plugable::onAll<Options>(boost::bind(&Options::consume, _1, n, p, v));
+		void operator()(const Glib::ustring & n, const Glib::ustring & p, const Glib::ustring & v, const Options::CurrentPlatform & cp) const {
+			Plugable::onAll<Options>(boost::bind(&Options::consume, _1, n, p, v, cp));
 		}
 		const Options::Option * get(const Glib::ustring & n) const {
 			const Options::Option * rtn = NULL;
@@ -19,7 +19,7 @@ class DefaultConfigConsumer : public ConfigConsumer {
 };
 
 void
-OptionsSource::loadSources()
+OptionsSource::loadSources(const Options::CurrentPlatform & platform)
 {
 	const auto & configs = Plugable::ComponentType<OptionsSource>::components();
 	if (std::find_if(configs->begin(), configs->end(), boost::bind(&OptionsSource::needReload, _1)) != configs->end()) {
@@ -27,7 +27,7 @@ OptionsSource::loadSources()
 
 		DefaultConfigConsumer dcc;
 		BOOST_FOREACH(const auto & c, *configs) {
-			c->loadInto(dcc);
+			c->loadInto(dcc, platform);
 		}
 		Plugable::onAllComponents(boost::bind(&ComponentLoader::onConfigLoad, _1));
 		
diff --git a/project2/common/optionsSource.h b/project2/common/optionsSource.h
index 49bb876..d6f41ab 100644
--- a/project2/common/optionsSource.h
+++ b/project2/common/optionsSource.h
@@ -9,17 +9,17 @@
 
 class ConfigConsumer {
 	public:
-		virtual void operator()(const Glib::ustring &, const Glib::ustring &, const Glib::ustring &) const = 0;
+		virtual void operator()(const Glib::ustring &, const Glib::ustring &, const Glib::ustring &, const Options::CurrentPlatform &) const = 0;
 		virtual const Options::Option * get(const Glib::ustring & name) const = 0;
 };
 
 /// Base class of things that load options
 class OptionsSource {
 	public:
-		virtual void loadInto(const ConfigConsumer &) const = 0;
+		virtual void loadInto(const ConfigConsumer &, const Options::CurrentPlatform & platform) const = 0;
 		virtual bool needReload() const = 0;
 
-		static void loadSources();
+		static void loadSources(const Options::CurrentPlatform & platform);
 };
 typedef boost::intrusive_ptr<OptionsSource> OptionsSourcePtr;
 
diff --git a/project2/common/presenter.cpp b/project2/common/presenter.cpp
index 1e5bbf2..4e12307 100644
--- a/project2/common/presenter.cpp
+++ b/project2/common/presenter.cpp
@@ -1,7 +1,6 @@
 #include <pch.hpp>
 #include "presenter.h"
 #include "dataSource.h"
-#include "appEngine.h"
 #include <boost/foreach.hpp>
 
 NameValuePairPresenter::NameValuePairPresenter()
diff --git a/project2/common/presenter.h b/project2/common/presenter.h
index f9069de..3ea56e7 100644
--- a/project2/common/presenter.h
+++ b/project2/common/presenter.h
@@ -39,7 +39,7 @@ class MultiRowSetPresenter : public RowSetPresenter {
 		virtual void finishRowSet() const = 0;
 		virtual void addNewArray(const Glib::ustring & name, bool objects) const = 0;
 		virtual void finishArray(bool objects) const = 0;
-		virtual void init() = 0;
+		virtual void init(ExecContext *) = 0;
 		virtual void finalizeContent() const;
 };
 
@@ -77,7 +77,7 @@ typedef boost::intrusive_ptr<RowSetPresenter> RowSetPresenterPtr;
 typedef boost::intrusive_ptr<MultiRowSetPresenter> MultiRowSetPresenterPtr;
 typedef boost::intrusive_ptr<NameValuePairPresenter> NameValuePairPresenterPtr;
 
-typedef GenLoader<MultiRowSetPresenter, ScriptNodePtr, ObjectSource> PresenterLoader;
+typedef GenLoader<MultiRowSetPresenter, ScriptNodePtr, ObjectSource, ExecContext *> PresenterLoader;
 
 #endif
 
diff --git a/project2/common/presenterCache.cpp b/project2/common/presenterCache.cpp
index 6ca3661..31fdc8f 100644
--- a/project2/common/presenterCache.cpp
+++ b/project2/common/presenterCache.cpp
@@ -4,7 +4,7 @@
 PresenterCache::PresenterCache(ScriptNodePtr s) :
 	SourceObject(s),
 	IHaveParameters(s),
-	encoding(s->value("encoding", "utf-8").as<std::string>())
+	encoding(s->value("encoding", "utf-8", NULL).as<std::string>())
 {
 }
 
@@ -15,8 +15,8 @@ PresenterCache::flushCache()
 
 class WriteToCache : public TransformImpl<WritableContent, PresenterCache> {
 	public:
-		void transform(const WritableContent * wc, PresenterCache * pc) const {
-			wc->writeTo(pc->writeCache(wc->getContentType(), pc->encoding), pc->encoding);
+		void transform(const WritableContent * wc, PresenterCache * pc, ExecContext * ec) const {
+			wc->writeTo(pc->writeCache(wc->getContentType(), pc->encoding, ec), pc->encoding, ec);
 		}
 };
 DECLARE_TRANSFORM(WriteToCache);
diff --git a/project2/common/presenterCache.h b/project2/common/presenterCache.h
index 799181b..b0adab8 100644
--- a/project2/common/presenterCache.h
+++ b/project2/common/presenterCache.h
@@ -8,9 +8,9 @@
 class PresenterCache : public SourceObject, public virtual TransformSource, public StaticContent, public SourceOf<StaticContent>, public IHaveParameters {
 	public:
 		PresenterCache(ScriptNodePtr);
-		virtual bool check(time_t scriptMtime) const = 0;
+		virtual bool check(time_t scriptMtime, ExecContext *) const = 0;
 
-		virtual std::ostream & writeCache(const std::string & ct, const std::string & encoding) = 0;
+		virtual std::ostream & writeCache(const std::string & ct, const std::string & encoding, ExecContext *) = 0;
 		virtual void flushCache();
 		const std::string encoding;
 };
diff --git a/project2/common/rowProcessor.cpp b/project2/common/rowProcessor.cpp
index 4e3bf1d..26ca433 100644
--- a/project2/common/rowProcessor.cpp
+++ b/project2/common/rowProcessor.cpp
@@ -8,10 +8,10 @@
 
 RowProcessor::RowProcessor(ScriptNodePtr p) :
 	IHaveParameters(p),
-	recordSource(p->value("source").as<std::string>()),
-	filter(p->value("filter", "").as<Glib::ustring>()),
-	CROE(p->value("cacheRowsOnError", false)),
-	IRSE(p->value("ignoreRowSourceError", false))
+	recordSource(p->value("source", NULL).as<std::string>()),
+	filter(p->value("filter", "", NULL).as<Glib::ustring>()),
+	CROE(p->value("cacheRowsOnError", false, NULL)),
+	IRSE(p->value("ignoreRowSourceError", false, NULL))
 {
 	p->script->loader.addLoadTarget(p, Storer::into<ElementLoader>(&caches));
 	p->script->loader.addLoadTarget(p, Storer::into<ElementLoader>(&tests));
@@ -24,19 +24,19 @@ RowProcessor::loadComplete(const CommonObjects * co)
 }
 
 void
-RowProcessor::execute() const
+RowProcessor::execute(ExecContext * ec, const RowProcessorCallback & cb) const
 {
 	IHaveParameters::push(this);
 	ScopeObject _ihp(
 			boost::bind(&IHaveParameters::pop),
-			boost::bind(&RowProcessor::saveCaches, this),
-			boost::bind((CROE ? &RowProcessor::saveCaches : &RowProcessor::discardCaches), this),
+			boost::bind(&RowProcessor::saveCaches, this, ec),
+			boost::bind((CROE ? &RowProcessor::saveCaches : &RowProcessor::discardCaches), this, ec),
 			boost::bind(&TargetCaches::clear, &tc));
 	BOOST_FOREACH(const CachePtr & c, caches) {
-		if (c->checkAndExecute(source->name, filter, this)) {
+		if (c->checkAndExecute(ec, source->name, filter, this, cb)) {
 			return;
 		}
-		RowSetPresenterPtr p = c->openFor(source->name, filter, this);
+		RowSetPresenterPtr p = c->openFor(ec, source->name, filter, this);
 		if (p) {
 			tc.insert(TargetCachePtr(new TargetCache(p, c)));
 		}
@@ -47,44 +47,44 @@ RowProcessor::execute() const
 	}
 	if (IRSE) {
 		try {
-			source->execute(filter, this);
+			source->execute(filter, cb, ec);
 		}
 		catch (const std::exception & e) {
 			Logger()->messagebf(LOG_WARNING, "Source '%s' failed with '%s'", source->name, e.what());
 		}
 	}
 	else {
-		source->execute(filter, this);
+		source->execute(filter, cb, ec);
 	}
 }
 
 void
-RowProcessor::saveCaches() const
+RowProcessor::saveCaches(ExecContext * ec) const
 {
 	BOOST_FOREACH(const TargetCaches::value_type & c, tc) {
-		c->get<1>()->save(source->name, filter, this);
+		c->get<1>()->save(ec, source->name, filter, this);
 	}
 }
 
 void
-RowProcessor::discardCaches() const
+RowProcessor::discardCaches(ExecContext * ec) const
 {
 	BOOST_FOREACH(const TargetCaches::value_type & c, tc) {
-		c->get<1>()->discard(source->name, filter, this);
+		c->get<1>()->discard(ec, source->name, filter, this);
 	}
 }
 
 void
-RowProcessor::rowReadyInternal(const RowState * rs) const
+RowProcessor::rowReadyInternal(const RowState * rs, const RowProcessorCallback & cb, ExecContext * ec) const
 {
 	BOOST_FOREACH(const TargetCaches::value_type & c, tc) {
 		c->get<0>()->addNewRow(filter.empty() ? "row" : filter);
-		rs->foreachColumn(boost::bind(&RowSetPresenter::addNamedValue, c->get<0>(), _2, _3));
+		rs->foreachColumn(ec, boost::bind(&RowSetPresenter::addNamedValue, c->get<0>(), _2, _3));
 		rs->foreachAttr(boost::bind(&RowSetPresenter::addAttribute, c->get<0>(), _1, _2));
 		c->get<0>()->finishRow();
 	}
-	if (boost::algorithm::all(tests, boost::bind(&Test::passes, _1))) {
-		rowReady(rs);
+	if (boost::algorithm::all(tests, boost::bind(&Test::passes, _1, ec))) {
+		cb(rs);
 	}
 }
 
diff --git a/project2/common/rowProcessor.h b/project2/common/rowProcessor.h
index 04a61bf..70f453c 100644
--- a/project2/common/rowProcessor.h
+++ b/project2/common/rowProcessor.h
@@ -10,6 +10,7 @@
 #include "scriptStorage.h"
 
 class Presenter;
+class ExecContext;
 
 /// Base class for Project2 components that work with row sets
 class RowProcessor : public IHaveParameters {
@@ -25,12 +26,11 @@ class RowProcessor : public IHaveParameters {
 
 	protected:
 		boost::intrusive_ptr<RowSet> source;
-		void execute() const;
+		void execute(ExecContext *, const RowProcessorCallback &) const;
 
 	private:
 		friend class RowState;
-		void rowReadyInternal(const RowState *) const;
-		virtual void rowReady(const RowState *) const = 0;
+		void rowReadyInternal(const RowState *, const RowProcessorCallback &, ExecContext *) const;
 		typedef ANONSTORAGEOF(Test) Tests;
 		Tests tests;
 		typedef ANONORDEREDSTORAGEOF(Cache) Caches;
@@ -40,8 +40,8 @@ class RowProcessor : public IHaveParameters {
 		typedef std::set<TargetCachePtr> TargetCaches;
 		mutable TargetCaches tc;
 
-		void saveCaches() const;
-		void discardCaches() const;
+		void saveCaches(ExecContext *) const;
+		void discardCaches(ExecContext *) const;
 };
 
 #endif
diff --git a/project2/common/rowSet.cpp b/project2/common/rowSet.cpp
index 0378b51..daa81b3 100644
--- a/project2/common/rowSet.cpp
+++ b/project2/common/rowSet.cpp
@@ -4,7 +4,6 @@
 #include "scopeObject.h"
 #include "logger.h"
 #include "variables.h"
-#include "rowProcessor.h"
 #include <boost/foreach.hpp>
 #include <boost/bind.hpp>
 
@@ -29,12 +28,12 @@ RowState::~RowState()
 }
 
 void
-RowState::process(const RowProcessor * rp, bool r)
+RowState::process(const RowProcessorCallback & rp, bool r)
 {
 	rowNum += 1;
 	stack.push_back(this);
 	ScopeObject s(boost::bind(&RowState::RowValuesStack::pop_back, &stack));
-	rp->rowReadyInternal(this);
+	rp(this);
 	if (r) {
 		reset();
 	}
@@ -70,13 +69,13 @@ RowState::resolveAttr(const Glib::ustring & attrName) const
 }
 
 VariableType
-RowState::getCurrentValue(const Glib::ustring & col) const
+RowState::getCurrentValue(ExecContext * ec, const Glib::ustring & col) const
 {
 	const Columns & columns = getColumns();
 	Columns::index<byColName>::type::iterator di = columns.get<byColName>().find(col);
 	if (di != columns.get<byColName>().end()) {
 		if (fields[(*di)->idx].isNull()) {
-			return (*di)->defValue;
+			return (*di)->defValue(ec);
 		}
 		return fields[(*di)->idx];
 	}
@@ -84,11 +83,11 @@ RowState::getCurrentValue(const Glib::ustring & col) const
 }
 
 void
-RowState::foreachColumn(const ColumnAction & action) const
+RowState::foreachColumn(ExecContext * ec, const ColumnAction & action) const
 {
 	const Columns & columns = getColumns();
 	BOOST_FOREACH(const Columns::value_type & col, columns.get<byColName>()) {
-		action(col->idx, col->name, (!boost::get<Null>(&fields[col->idx])) ? fields[col->idx] : col->defValue());
+		action(col->idx, col->name, (!boost::get<Null>(&fields[col->idx])) ? fields[col->idx] : col->defValue(ec));
 	}
 }
 
diff --git a/project2/common/rowSet.h b/project2/common/rowSet.h
index 2845983..50dd3fd 100644
--- a/project2/common/rowSet.h
+++ b/project2/common/rowSet.h
@@ -8,13 +8,13 @@
 #include "columns.h"
 #include <boost/function.hpp>
 
-class RowProcessor;
 class RowSet;
 class VariableType;
+class RowState;
+
 typedef boost::intrusive_ptr<RowSet> RowSetPtr;
 typedef boost::intrusive_ptr<const RowSet> ConstRowSetPtr;
-
-class RowState;
+typedef boost::function<void(const RowState *)> RowProcessorCallback;
 
 /// Base class for Project2 components that provide a row set representation of data
 class RowSet : public SourceObject {
@@ -26,7 +26,7 @@ class RowSet : public SourceObject {
 		RowSet(ScriptNodePtr);
 		virtual ~RowSet() = 0;
 
-		virtual void execute(const Glib::ustring &, const RowProcessor *) const = 0;
+		virtual void execute(const Glib::ustring &, const RowProcessorCallback &, ExecContext *) const = 0;
 };
 
 class RowState {
@@ -40,12 +40,12 @@ class RowState {
 		SimpleMessageException(AttributeDoesNotExist);
 
 		VariableType getRowNum() const;
-		void process(const RowProcessor *, bool reset = true);
+		void process(const RowProcessorCallback &, bool reset = true);
 		void blankRow();
 		void reset();
-		virtual VariableType getCurrentValue(const Glib::ustring & id) const;
+		virtual VariableType getCurrentValue(ExecContext *, const Glib::ustring & id) const;
 		virtual RowAttribute resolveAttr(const Glib::ustring & attrName) const;
-		void foreachColumn(const ColumnAction & action) const;
+		void foreachColumn(ExecContext * ec, const ColumnAction & action) const;
 		virtual void foreachAttr(const AttrAction & action) const;
 		virtual const Columns & getColumns() const = 0;
 
diff --git a/project2/common/rowView.cpp b/project2/common/rowView.cpp
index c0e5cae..b9508bd 100644
--- a/project2/common/rowView.cpp
+++ b/project2/common/rowView.cpp
@@ -16,9 +16,7 @@ RowView::RowView(ScriptNodePtr p) :
 	rootName(p, "rootname", Null()),
 	recordName(p, "recordname"),
 	required(p, "required", false),
-	isObject(p, "isobject", true),
-	presenter(NULL),
-	rowsFound(false)
+	isObject(p, "isobject", true)
 {
 	BOOST_FOREACH(ScriptNodePtr node, p->childrenIn("columns")) {
 		viewColumns.insert(Columns::value_type(node->get_name(), Variable(node)));
@@ -39,67 +37,66 @@ RowView::loadComplete(const CommonObjects * co)
 }
 
 void
-RowView::rowReady(const RowState * rs) const
+RowView::rowReady(const RowState * rs, const MultiRowSetPresenter * presenter, ExecContext * ec, bool & rowsFound) const
 {
 	rowsFound = true;
-	if (isObject()) {
-		presenter->addNewRow(recordName());
+	if (isObject(ec)) {
+		presenter->addNewRow(recordName(ec));
 	}
 	if (viewColumns.empty()) {
-		rs->foreachColumn(boost::bind(&RowSetPresenter::addNamedValue, presenter, _2, _3));
+		rs->foreachColumn(ec, boost::bind(&RowSetPresenter::addNamedValue, presenter, _2, _3));
 	}
 	else {
 		BOOST_FOREACH(const Columns::value_type & col, viewColumns) {
-			presenter->addNamedValue(col.first, col.second);
+			presenter->addNamedValue(col.first, col.second(ec));
 		}
 	}
-	if (isObject()) {
-		executeChildren();
+	if (isObject(ec)) {
+		executeChildren(presenter, ec);
 		presenter->finishRow();
 	}
 	BOOST_FOREACH(SetAggregateCPtr s, setAggregates) {
-		s->pushValue();
+		s->pushValue(ec);
 	}
 	BOOST_FOREACH(ValueAggregateCPtr a, valueAggregates) {
-		a->pushValue();
+		a->pushValue(ec);
 	}
 }
 
 void
-RowView::execute(const MultiRowSetPresenter * p) const
+RowView::execute(const MultiRowSetPresenter * p, ExecContext * ec) const
 {
-	rowsFound = false;
-	presenter = p;
-	if (!rootName().isNull()) {
-		presenter->addNewRowSet(rootName());
+	if (!rootName(ec).isNull()) {
+		p->addNewRowSet(rootName(ec));
 	}
-	ScopeObject pres(rootName().isNull() ? ScopeObject::Event() : boost::bind(&MultiRowSetPresenter::finishRowSet, p));
+	bool rowsFound = false;
+	ScopeObject pres(rootName(ec).isNull() ? ScopeObject::Event() : boost::bind(&MultiRowSetPresenter::finishRowSet, p));
 	{
-		presenter->addNewArray(recordName(), true);
+		p->addNewArray(recordName(ec), true);
 		ScopeObject pres(boost::bind(&MultiRowSetPresenter::finishArray, p, true));
-		RowProcessor::execute();
+		RowProcessor::execute(ec, boost::bind(&RowView::rowReady, this, _1, p, ec, boost::ref(rowsFound)));
 	}
-	if (required() && !rowsFound) {
+	if (required(ec) && !rowsFound) {
 		throw EmptyRequiredRows(name);
 	}
 
 	BOOST_FOREACH(SetAggregateCPtr s, setAggregates) {
-		presenter->addNewArray(s->name, false);
+		p->addNewArray(s->name, false);
 		ScopeObject pres(boost::bind(&MultiRowSetPresenter::finishArray, p, false));
 		s->onResultValues(boost::bind(&MultiRowSetPresenter::addNamedValue, p, "value", _1));
 		s->reset();
 	}
 	BOOST_FOREACH(ValueAggregateCPtr a, valueAggregates) {
-		presenter->addNamedValue(a->name, a->resultValue());
+		p->addNamedValue(a->name, a->resultValue());
 		a->reset();
 	}
 }
 
 void
-RowView::executeChildren() const
+RowView::executeChildren(const MultiRowSetPresenter * presenter, ExecContext * ec) const
 {
 	BOOST_FOREACH(const SubViews::value_type & sq, subViews) {
-		sq->execute(presenter);
+		sq->execute(presenter, ec);
 	}
 }
 
diff --git a/project2/common/rowView.h b/project2/common/rowView.h
index 534a06f..d2745db 100644
--- a/project2/common/rowView.h
+++ b/project2/common/rowView.h
@@ -13,8 +13,8 @@ class RowView : public View, public RowProcessor {
 		virtual ~RowView();
 
 		void loadComplete(const CommonObjects *);
-		void execute(const MultiRowSetPresenter *) const;
-		void rowReady(const RowState *) const;
+		void execute(const MultiRowSetPresenter *, ExecContext *) const;
+		void rowReady(const RowState *, const MultiRowSetPresenter *, ExecContext *, bool & found) const;
 
 		const Variable rootName;
 		const Variable recordName;
@@ -25,16 +25,13 @@ class RowView : public View, public RowProcessor {
 		typedef std::map<Glib::ustring, Variable> Columns;
 		Columns viewColumns;
 
-		void executeChildren() const;
+		void executeChildren(const MultiRowSetPresenter * presenter, ExecContext *) const;
 		typedef ANONORDEREDSTORAGEOF(View) SubViews;
 		SubViews subViews;
 		typedef ANONSTORAGEOF(ValueAggregate) ValueAggregates;
 		ValueAggregates valueAggregates;
 		typedef ANONSTORAGEOF(SetAggregate) SetAggregates;
 		SetAggregates setAggregates;
-		mutable const MultiRowSetPresenter * presenter;
-
-		mutable bool rowsFound;
 };
 
 #endif
diff --git a/project2/common/scriptLoader.cpp b/project2/common/scriptLoader.cpp
index ab02f02..fe8799b 100644
--- a/project2/common/scriptLoader.cpp
+++ b/project2/common/scriptLoader.cpp
@@ -3,7 +3,6 @@
 #include "scriptLoader.h"
 #include "scriptStorage.h"
 #include "library.h"
-#include "appEngine.h"
 #include <boost/shared_ptr.hpp>
 #include <boost/foreach.hpp>
 #include <boost/function.hpp>
diff --git a/project2/common/scripts.cpp b/project2/common/scripts.cpp
index 767ff0d..f065e4b 100644
--- a/project2/common/scripts.cpp
+++ b/project2/common/scripts.cpp
@@ -32,20 +32,20 @@ ScriptNode::variable(const Glib::ustring & n, const VariableType & def) const
 }
 
 VariableType
-ScriptNode::value(const Glib::ustring & n, const VariableType & def) const
+ScriptNode::value(const Glib::ustring & n, const VariableType & def, ExecContext * ec) const
 {
 	VariableType r;
-	if (applyValue(n, r)) {
+	if (applyValue(n, r, ec)) {
 		return r;
 	}
 	return def;
 }
 
 VariableType
-ScriptNode::value(const Glib::ustring & n) const
+ScriptNode::value(const Glib::ustring & n, ExecContext * ec) const
 {
 	VariableType r;
-	if (applyValue(n, r)) {
+	if (applyValue(n, r, ec)) {
 		return r;
 	}
 	throw ValueNotFound(n);
diff --git a/project2/common/scripts.h b/project2/common/scripts.h
index 0cb478c..7bf6326 100644
--- a/project2/common/scripts.h
+++ b/project2/common/scripts.h
@@ -18,6 +18,7 @@ SimpleMessage2Exception(ScriptNotFound);
 SimpleMessage2Exception(DependencyNotFound);
 
 class VariableImpl;
+class ExecContext;
 
 class Scripts {
 	public:
@@ -45,12 +46,12 @@ class ScriptNode : public IntrusivePtrBase {
 		virtual ScriptNodes childrenIn(const Glib::ustring & sub) const = 0;
 		
 		virtual bool valueExists(const Glib::ustring & name) const = 0;
-		virtual bool applyValue(const Glib::ustring & name, VariableType & target) const = 0;
+		virtual bool applyValue(const Glib::ustring & name, VariableType & target, ExecContext *) const = 0;
 		virtual VariableImpl * variable(const boost::optional<Glib::ustring> & defaultSource = boost::optional<Glib::ustring>()) const = 0;
 		virtual VariableImpl * variable(const Glib::ustring & name) const = 0;
 		VariableImpl * variable(const Glib::ustring & name, const VariableType & def) const;
-		VariableType value(const Glib::ustring & name) const;
-		VariableType value(const Glib::ustring & name, const VariableType & def) const;
+		VariableType value(const Glib::ustring & name, ExecContext *) const;
+		VariableType value(const Glib::ustring & name, const VariableType & def, ExecContext *) const;
 		virtual void composeWithCallbacks(const LiteralCallback &, const NodeCallback &) const = 0;
 
 		const ScriptReaderPtr script;
diff --git a/project2/common/sessionClearTask.cpp b/project2/common/sessionClearTask.cpp
index b3b1000..265bb1c 100644
--- a/project2/common/sessionClearTask.cpp
+++ b/project2/common/sessionClearTask.cpp
@@ -2,15 +2,15 @@
 #include <boost/foreach.hpp>
 #include "scriptLoader.h"
 #include "sessionClearTask.h"
-#include "appEngine.h"
 #include "session.h"
+#include "execContext.h"
 
 DECLARE_LOADER("sessionclear", SessionClearTask);
 
 SessionClearTask::SessionClearTask(ScriptNodePtr p) :
 	SourceObject(p),
 	Task(p),
-	key(p->value("key").as<Glib::ustring>())
+	key(p->value("key", NULL).as<Glib::ustring>())
 {
 }
 
@@ -19,8 +19,8 @@ SessionClearTask::~SessionClearTask()
 }
 
 void
-SessionClearTask::execute() const
+SessionClearTask::execute(ExecContext * ec) const
 {
-	ApplicationEngine::getCurrent()->session()->ClearValue(key);
+	ec->getSession()->ClearValue(key);
 }
 
diff --git a/project2/common/sessionClearTask.h b/project2/common/sessionClearTask.h
index c7def60..ead88bf 100644
--- a/project2/common/sessionClearTask.h
+++ b/project2/common/sessionClearTask.h
@@ -15,7 +15,7 @@ class SessionClearTask : public Task {
 		SessionClearTask(ScriptNodePtr p);
 		virtual ~SessionClearTask();
 
-		void execute() const;
+		void execute(ExecContext *) const;
 
 		const Glib::ustring key;
 };
diff --git a/project2/common/sessionContainer.cpp b/project2/common/sessionContainer.cpp
index e9c76c9..41c3f98 100644
--- a/project2/common/sessionContainer.cpp
+++ b/project2/common/sessionContainer.cpp
@@ -1,6 +1,5 @@
 #include <pch.hpp>
 #include "sessionContainer.h"
-#include "environment.h"
 
 SessionContainer::SessionContainer()
 {
diff --git a/project2/common/sessionSetTask.cpp b/project2/common/sessionSetTask.cpp
index aca5b26..f46571b 100644
--- a/project2/common/sessionSetTask.cpp
+++ b/project2/common/sessionSetTask.cpp
@@ -2,15 +2,15 @@
 #include <boost/foreach.hpp>
 #include "scriptLoader.h"
 #include "sessionSetTask.h"
-#include "appEngine.h"
 #include "session.h"
+#include "execContext.h"
 
 DECLARE_LOADER("sessionset", SessionSetTask);
 
 SessionSetTask::SessionSetTask(ScriptNodePtr p) :
 	SourceObject(p),
 	Task(p),
-	key(p->value("key").as<Glib::ustring>()),
+	key(p->value("key", NULL).as<Glib::ustring>()),
 	value(p, "value")
 {
 }
@@ -20,8 +20,8 @@ SessionSetTask::~SessionSetTask()
 }
 
 void
-SessionSetTask::execute() const
+SessionSetTask::execute(ExecContext * ec) const
 {
-	ApplicationEngine::getCurrent()->session()->SetValue(key, value);
+	ec->getSession()->SetValue(key, value(ec));
 }
 
diff --git a/project2/common/sessionSetTask.h b/project2/common/sessionSetTask.h
index 8e88837..d38c216 100644
--- a/project2/common/sessionSetTask.h
+++ b/project2/common/sessionSetTask.h
@@ -16,7 +16,7 @@ class SessionSetTask : public Task {
 		SessionSetTask(ScriptNodePtr p);
 		virtual ~SessionSetTask();
 
-		void execute() const;
+		void execute(ExecContext *) const;
 
 		const Glib::ustring key;
 		const Variable value;
diff --git a/project2/common/singleton.cpp b/project2/common/singleton.cpp
index 0aaf5f7..eff3f94 100644
--- a/project2/common/singleton.cpp
+++ b/project2/common/singleton.cpp
@@ -10,29 +10,28 @@ class Singleton : public View {
 		Singleton(ScriptNodePtr p) :
 			SourceObject(p),
 			View(p),
-			rootName(p, "rootname"),
-			presenter(NULL) {
+			rootName(p, "rootname")
+		{
 			BOOST_FOREACH(ScriptNodePtr node, p->childrenIn("columns")) {
 				viewColumns.insert(Columns::value_type(node->get_name(), Variable(node)));
 			}
 			p->script->loader.addLoadTarget(p, Storer::into<ElementLoader>(&subViews));
 		}
-		void execute(const MultiRowSetPresenter * p) const
+		void execute(const MultiRowSetPresenter * p, ExecContext * ec) const
 		{
-			presenter = p;
-			presenter->addNewRowSet(rootName());
+			p->addNewRowSet(rootName(ec));
 			ScopeObject pres(boost::bind(&MultiRowSetPresenter::finishRowSet, p));
 			BOOST_FOREACH(const Columns::value_type & col, viewColumns) {
-				p->addNamedValue(col.first, col.second);
+				p->addNamedValue(col.first, col.second(ec));
 			}
 		}
 
 		const Variable rootName;
 	private:
-		void executeChildren() const
+		void executeChildren(const MultiRowSetPresenter * p, ExecContext * ec) const
 		{
 			BOOST_FOREACH(const SubViews::value_type & sq, subViews) {
-				sq->execute(presenter);
+				sq->execute(p, ec);
 			}
 		}
 
@@ -41,7 +40,6 @@ class Singleton : public View {
 
 		typedef ANONSTORAGEOF(View) SubViews;
 		SubViews subViews;
-		mutable const MultiRowSetPresenter * presenter;
 };
 DECLARE_LOADER("singleton", Singleton);
 
diff --git a/project2/common/sourceObject.cpp b/project2/common/sourceObject.cpp
index 03f06b5..b451919 100644
--- a/project2/common/sourceObject.cpp
+++ b/project2/common/sourceObject.cpp
@@ -8,7 +8,7 @@ unsigned int SourceObject::loadOrder = 1;
 SimpleMessageException(ComponentNotFound);
 
 SourceObject::SourceObject(ScriptNodePtr p) :
-	name(p ? p->value("name", "anon").as<std::string>() : "anon"),
+	name(p ? p->value("name", "anon", NULL).as<std::string>() : "anon"),
 	order(loadOrder++),
 	script(p->script.get())
 {
diff --git a/project2/common/stream.h b/project2/common/stream.h
index eebefab..ad3ee79 100644
--- a/project2/common/stream.h
+++ b/project2/common/stream.h
@@ -4,12 +4,14 @@
 #include "sourceObject.h"
 #include <boost/function.hpp>
 
+class ExecContext;
+
 class Stream : public SourceObject {
 	public:
 		template<typename... X> Stream(const X &... x) : SourceObject(x...) { }
 
 		typedef boost::function<size_t(const char *, size_t)> Sink;
-		virtual void runStream(const Sink &) const = 0;
+		virtual void runStream(const Sink &, ExecContext *) const = 0;
 };
 typedef boost::intrusive_ptr<Stream> StreamPtr;
 
diff --git a/project2/common/structExceptHandling.cpp b/project2/common/structExceptHandling.cpp
index 0881d6d..917f030 100644
--- a/project2/common/structExceptHandling.cpp
+++ b/project2/common/structExceptHandling.cpp
@@ -23,22 +23,22 @@ StructuredExceptionHandler::loadComplete(const CommonObjects * co)
 }
 
 void
-StructuredExceptionHandler::execute() const
+StructuredExceptionHandler::execute(ExecContext * ec) const
 {
 	try {
-		run(normal);
+		run(normal, ec);
 	}
 	catch (...) {
 		try {
-			run(catches);
-			run(finallies);
+			run(catches, ec);
+			run(finallies, ec);
 			return;
 		}
 		catch (...) {
 		}
-		run(finallies);
+		run(finallies, ec);
 		throw;
 	}
-	run(finallies);
+	run(finallies, ec);
 }
 
diff --git a/project2/common/structExceptHandling.h b/project2/common/structExceptHandling.h
index 067c389..b6702f1 100644
--- a/project2/common/structExceptHandling.h
+++ b/project2/common/structExceptHandling.h
@@ -8,7 +8,7 @@ class StructuredExceptionHandler : public IHaveSubTasks {
 		StructuredExceptionHandler(ScriptNodePtr);
 
 		void loadComplete(const CommonObjects*);
-		void execute() const;
+		void execute(ExecContext * ec) const;
 
 	private:
 		Tasks catches, finallies;
diff --git a/project2/common/task.h b/project2/common/task.h
index 5303f15..15ccfbd 100644
--- a/project2/common/task.h
+++ b/project2/common/task.h
@@ -9,7 +9,7 @@ class Task : public NoOutputExecute {
 	public:
 		Task(ScriptNodePtr p);
 		virtual ~Task();
-		virtual void execute() const = 0;
+		virtual void execute(ExecContext *) const = 0;
 };
 
 #endif
diff --git a/project2/common/taskHost.cpp b/project2/common/taskHost.cpp
index cbfe7c3..07f7601 100644
--- a/project2/common/taskHost.cpp
+++ b/project2/common/taskHost.cpp
@@ -27,11 +27,11 @@ TaskHost::loadComplete(const CommonObjects * co)
 }
 
 void
-TaskHost::execute() const
+TaskHost::execute(ExecContext * ec) const
 {
 	loadScriptComponents();
 	ScopeObject txHandler(ScopeObject::Event(), boost::bind(&TaskHost::commitAll, this), boost::bind(&TaskHost::rollbackAll, this));
-	run(tasks);
+	run(tasks, ec);
 }
 
 void
diff --git a/project2/common/taskHost.h b/project2/common/taskHost.h
index edecda6..e4b8b3a 100644
--- a/project2/common/taskHost.h
+++ b/project2/common/taskHost.h
@@ -15,7 +15,7 @@ class TaskHost : public IHaveSubTasks, virtual public CheckHost, virtual public
 		virtual ~TaskHost();
 
 		void loadComplete(const CommonObjects *);
-		void execute() const;
+		void execute(ExecContext *) const;
 
 		Tasks tasks;
 
diff --git a/project2/common/test.h b/project2/common/test.h
index 4f87c10..7cf563c 100644
--- a/project2/common/test.h
+++ b/project2/common/test.h
@@ -4,10 +4,12 @@
 #include "sourceObject.h"
 #include "scripts.h"
 
+class ExecContext;
+
 class Test : public virtual SourceObject {
 	public:
 		Test(ScriptNodePtr);
-		virtual bool passes() const = 0;
+		virtual bool passes(ExecContext *) const = 0;
 		virtual void reset() const;
 };
 typedef boost::intrusive_ptr<const Test> TestPtr;
diff --git a/project2/common/transform.cpp b/project2/common/transform.cpp
index fb92486..efe9bf6 100644
--- a/project2/common/transform.cpp
+++ b/project2/common/transform.cpp
@@ -19,7 +19,7 @@ class TransformTargetStorer : public Storer {
 		{
 			TransformChainLinkPtr O = boost::dynamic_pointer_cast<TransformChainLink>(o);
 			if (O) {
-				transformSource->addTarget(O, s);
+				transformSource->addTarget(O, NULL, s);
 			}
 			return O;
 		}
@@ -44,13 +44,13 @@ TransformChainLink::~TransformChainLink()
 
 typedef std::map<std::string, boost::shared_ptr<TransformLoader> > TransformLoaderMap;
 void
-TransformSource::addTarget(TransformChainLinkPtr tcl, ScriptNodePtr e)
+TransformSource::addTarget(TransformChainLinkPtr tcl, ExecContext * ec, ScriptNodePtr e)
 {
 	BOOST_FOREACH(const TransformLoaderMap::value_type & tl, *Plugable::objLoaders<TransformLoader>()) {
 		TransformPtr t = tl.second->create();
 		if (t->canTransform(this, tcl.get())) {
 			if (e) {
-				t->configure(e);
+				t->configure(e, ec);
 			}
 			targets[tcl] = t;
 			return;
@@ -72,12 +72,12 @@ TransformSource::removeTarget(TransformChainLinkPtr tcl)
 }
 
 void
-TransformSource::doTransforms() const
+TransformSource::doTransforms(ExecContext * ec) const
 {
 	BOOST_FOREACH(const Targets::value_type & t, targets) {
-		t.second->transform(this, t.first.get());
+		t.second->transform(this, t.first.get(), ec);
 		if (const TransformSource * tr = dynamic_cast<const TransformSource *>(t.first.get())) {
-			tr->doTransforms();
+			tr->doTransforms(ec);
 		}
 	}
 }
@@ -90,16 +90,16 @@ TransformSource::getTargets() const
 
 class TransformWritableContentToStdStream : public TransformImpl<WritableContent, ostreamWrapper> {
 	public:
-		void transform(const WritableContent * wc, ostreamWrapper * o) const
+		void transform(const WritableContent * wc, ostreamWrapper * o, ExecContext * ec) const
 		{
-			wc->writeTo(o->strm, "UTF-8");
+			wc->writeTo(o->strm, "UTF-8", ec);
 		}
 };
 DECLARE_TRANSFORM(TransformWritableContentToStdStream);
 
 class TransformStaticContentToStdStream : public TransformImpl<StaticContent, ostreamWrapper> {
 	public:
-		void transform(const StaticContent * wc, ostreamWrapper * o) const
+		void transform(const StaticContent * wc, ostreamWrapper * o, ExecContext *) const
 		{
 			wc->writeTo(o->strm);
 		}
diff --git a/project2/common/transform.h b/project2/common/transform.h
index 3ae1063..34e91b7 100644
--- a/project2/common/transform.h
+++ b/project2/common/transform.h
@@ -6,6 +6,8 @@
 #include "scriptLoader.h"
 #include <map>
 
+class ExecContext;
+
 class TransformChainLink : public virtual IntrusivePtrBase {
 	public:
 		virtual ~TransformChainLink() = 0;
@@ -22,8 +24,8 @@ class TransformSource : public TransformChainLink {
 		TransformSource(ScriptNodePtr, ObjectSource);
 		void clearTargets();
 		void removeTarget(TransformChainLinkPtr);
-		void addTarget(TransformChainLinkPtr, ScriptNodePtr e = NULL);
-		void doTransforms() const;
+		void addTarget(TransformChainLinkPtr, ExecContext *, ScriptNodePtr e);
+		void doTransforms(ExecContext *) const;
 		const Targets & getTargets() const;
 	private:
 		virtual const TransformChainLink * object() const { return this; }
@@ -41,9 +43,9 @@ class SourceOf : public virtual TransformSource {
 
 class Transform : public virtual IntrusivePtrBase {
 	public:
-		virtual void transform(const TransformSource * src, TransformChainLink * dest) const = 0;
+		virtual void transform(const TransformSource * src, TransformChainLink * dest, ExecContext *) const = 0;
 		virtual bool canTransform(const TransformSource * src, TransformChainLink * dest) const = 0;
-		virtual void configure(ScriptNodePtr) { };
+		virtual void configure(ScriptNodePtr, ExecContext *) { };
 };
 
 typedef GenLoader<Transform> TransformLoader;
@@ -55,10 +57,10 @@ typedef GenLoader<TransformChainLink, ScriptNodePtr, ObjectSource> TransformTarg
 template <class Source, class Destination>
 class TransformImpl : public Transform {
 	public:
-		virtual void transform(const Source *, Destination *) const = 0;
-		void transform(const TransformSource * src, TransformChainLink * dest) const
+		virtual void transform(const Source *, Destination *, ExecContext *) const = 0;
+		void transform(const TransformSource * src, TransformChainLink * dest, ExecContext * ec) const
 		{
-			transform(dynamic_cast<const SourceOf<Source> *>(src)->operator const Source *(), dynamic_cast<Destination *>(dest));
+			transform(dynamic_cast<const SourceOf<Source> *>(src)->operator const Source *(), dynamic_cast<Destination *>(dest), ec);
 		}
 		bool canTransform(const TransformSource * src, TransformChainLink * dest) const
 		{
@@ -75,7 +77,7 @@ class WritableContent {
 		};
 		virtual Class getContentClass() const = 0;
 		virtual Glib::ustring getContentType() const = 0;
-		virtual void writeTo(std::ostream &, const std::string & encoding) const = 0;
+		virtual void writeTo(std::ostream &, const std::string & encoding, ExecContext *) const = 0;
 };
 
 class StaticContent {
diff --git a/project2/common/variables.cpp b/project2/common/variables.cpp
index 6f62dc1..a8ca808 100644
--- a/project2/common/variables.cpp
+++ b/project2/common/variables.cpp
@@ -5,7 +5,6 @@
 #include "iHaveParameters.h"
 #include "scriptLoader.h"
 #include "exceptions.h"
-#include "appEngine.h"
 #include "session.h"
 #include "rowSet.h"
 #include <stdexcept>
@@ -31,9 +30,9 @@ class VariableParent : public VariableImplDyn {
 	public:
 		VariableParent(ScriptNodePtr e) :
 			VariableImplDyn(e),
-			depth(e->value("depth", 1).as<int32_t>()),
+			depth(e->value("depth", 1, NULL).as<int32_t>()),
 			attr(e->valueExists("attribute")),
-			name((attr ? e->value("attribute") : e->value("name")).as<Glib::ustring>())
+			name((attr ? e->value("attribute", NULL) : e->value("name", NULL)).as<Glib::ustring>())
 		{
 		}
 		VariableParent(const Glib::ustring & n, bool a, unsigned int d) :
@@ -43,14 +42,14 @@ class VariableParent : public VariableImplDyn {
 			name(n)
 		{
 		}
-		VariableType value() const
+		VariableType value(ExecContext * ec) const
 		{
 			try {
 				if (!getValue) {
 					if (depth > RowState::Stack().size()) {
 						throw RowSet::ParentOutOfRange(depth);
 					}
-					bind(RowState::Stack()[RowState::Stack().size() - depth]);
+					bind(ec, RowState::Stack()[RowState::Stack().size() - depth]);
 				}
 				return getValue();
 			}
@@ -58,23 +57,23 @@ class VariableParent : public VariableImplDyn {
 				if (!defaultValue) {
 					throw;
 				}
-				return (*defaultValue)();
+				return (*defaultValue)(ec);
 			}
 			catch (RowSet::FieldDoesNotExist) {
 				if (!defaultValue) {
 					throw;
 				}
-				return (*defaultValue)();
+				return (*defaultValue)(ec);
 			}
 		}
 	protected:
-		void bind(const RowState * row) const
+		void bind(ExecContext * ec, const RowState * row) const
 		{
 			if (attr) {
 				getValue = boost::bind(row->resolveAttr(name));
 			}
 			else {
-				getValue = boost::bind(&RowState::getCurrentValue, row, name);
+				getValue = boost::bind(&RowState::getCurrentValue, row, ec, name);
 			}
 		}
 		const size_t depth;
diff --git a/project2/common/variables.h b/project2/common/variables.h
index 948f2d2..7713667 100644
--- a/project2/common/variables.h
+++ b/project2/common/variables.h
@@ -10,12 +10,14 @@
 #include "variableType.h"
 #include <boost/shared_ptr.hpp>
 
+class ExecContext;
+
 SimpleMessageException(UnknownVariableSource);
 
 /// Base class for Project2 variable accessors
 class VariableImpl : public IntrusivePtrBase {
 	public:
-		virtual VariableType value() const = 0;
+		virtual VariableType value(ExecContext *) const = 0;
 
 	protected:
 		virtual ~VariableImpl() = 0;
@@ -32,8 +34,7 @@ class Variable {
 
 		static Variable makeParent(const Glib::ustring & name, bool attr, unsigned int depth);
 
-		operator VariableType () const { return var->value(); }
-		VariableType operator()() const { return var->value(); }
+		VariableType operator()(ExecContext * ec) const { return var->value(ec); }
 
 	private:
 		Variable(VariableImpl *);
@@ -45,7 +46,7 @@ class Variable {
 class VariableImplDyn : public VariableImpl {
 	public:
 		VariableImplDyn(ScriptNodePtr e);
-		virtual VariableType value() const = 0;
+		virtual VariableType value(ExecContext *) const = 0;
 
 	protected:
 		boost::optional<Variable> defaultValue;
diff --git a/project2/common/variables/config.cpp b/project2/common/variables/config.cpp
index 51759d5..9b4cccb 100644
--- a/project2/common/variables/config.cpp
+++ b/project2/common/variables/config.cpp
@@ -3,7 +3,6 @@
 #include "../scriptLoader.h"
 #include "../scriptStorage.h"
 #include <boost/algorithm/string/predicate.hpp>
-#include "../appEngine.h"
 
 typedef std::map<Glib::ustring, VariableType> ConfigOptions;
 static ConfigOptions cfgOpts;
@@ -15,17 +14,17 @@ class VariableConfig : public VariableImplDyn {
 	public:
 		VariableConfig(ScriptNodePtr e) :
 			VariableImplDyn(e),
-			name(e->value("name").as<Glib::ustring>())
+			name(e->value("name", NULL).as<Glib::ustring>())
 		{
 		}
-		VariableType value() const
+		VariableType value(ExecContext * ec) const
 		{
 			const ConfigOptions::const_iterator i = cfgOpts.find(name);
 			if (i != cfgOpts.end()) {
 				return i->second;
 			}
 			if (defaultValue) {
-				return defaultValue.get()();
+				return defaultValue.get()(ec);
 			}
 			throw NoSuchConfigurationValue(name);
 		}
@@ -40,17 +39,17 @@ class VariableConfigLoader : public VariableLoader::For<VariableConfig> {
 				void reset() const {
 					cfgOpts.clear();
 				}
-				void consume(const Glib::ustring & n, const Glib::ustring & p, const VariableType & v) const {
+				void consume(const Glib::ustring & n, const Glib::ustring & p, const VariableType & v, const Options::CurrentPlatform & cp) const {
 					if (boost::algorithm::starts_with(n, "application.")) {
 						Glib::ustring k(n.substr(12));
 						const ConfigOptions::iterator i = cfgOpts.find(k);
 						if (i == cfgOpts.end()) {
-							if (p.empty() || p == Environment::getCurrent()->platform()) {
+							if (p.empty() || p == cp) {
 								cfgOpts.insert(ConfigOptions::value_type(k, v));
 							}
 						}
 						else {
-							if (p == Environment::getCurrent()->platform()) {
+							if (p == cp) {
 								i->second = v;
 							}
 						}
diff --git a/project2/common/variables/fixed.cpp b/project2/common/variables/fixed.cpp
index fdb67ed..4687c6a 100644
--- a/project2/common/variables/fixed.cpp
+++ b/project2/common/variables/fixed.cpp
@@ -6,7 +6,7 @@ VariableFixed::VariableFixed(VariableType v) :
 }
 
 VariableType
-VariableFixed::value() const
+VariableFixed::value(ExecContext *) const
 {
 	return var;
 }
diff --git a/project2/common/variables/fixed.h b/project2/common/variables/fixed.h
index ec8be1a..b1380dd 100644
--- a/project2/common/variables/fixed.h
+++ b/project2/common/variables/fixed.h
@@ -7,7 +7,7 @@
 class VariableFixed : public VariableImpl {
 	public:
 		VariableFixed(VariableType v);
-		VariableType value() const;
+		VariableType value(ExecContext * ec) const;
 
 	private:
 		VariableType var;
diff --git a/project2/common/variables/literal.cpp b/project2/common/variables/literal.cpp
index 11fb78a..3696346 100644
--- a/project2/common/variables/literal.cpp
+++ b/project2/common/variables/literal.cpp
@@ -19,7 +19,7 @@ append(VariableLiteral::Vals * vals, const Y & y)
 
 VariableLiteral::VariableLiteral(ScriptNodePtr s) {
 	try {
-		val = VariableType::make(s->value("value"), VariableType::getTypeFromName(s->value("type", "")));
+		val = VariableType::make(s->value("value", NULL), VariableType::getTypeFromName(s->value("type", "", NULL)));
 	}
 	catch (const ValueNotFound &) {
 		s->composeWithCallbacks(
@@ -29,17 +29,17 @@ VariableLiteral::VariableLiteral(ScriptNodePtr s) {
 }
 
 VariableType
-VariableLiteral::value() const
+VariableLiteral::value(ExecContext * ec) const
 {
 	if (vals.empty()) {
 		return val;
 	}
 	if (vals.size() == 1) {
-		return *vals.front();
+		return vals.front()->value(ec);
 	}
 	Glib::ustring v;
 	BOOST_FOREACH(PartCPtr p, vals) {
-		p->appendTo(v);
+		p->appendTo(ec, v);
 	}
 	return v;
 }
@@ -49,11 +49,12 @@ VariableLiteral::TextPart::TextPart(const Glib::ustring & e) :
 {
 }
 void
-VariableLiteral::TextPart::appendTo(Glib::ustring & str) const
+VariableLiteral::TextPart::appendTo(ExecContext *, Glib::ustring & str) const
 {
 	str += txt;
 }
-VariableLiteral::TextPart::operator VariableType() const
+VariableType
+VariableLiteral::TextPart::value(ExecContext *) const
 {
 	return txt;
 }
@@ -62,13 +63,14 @@ VariableLiteral::VarPart::VarPart(ScriptNodePtr e) : Variable(e)
 {
 }
 void
-VariableLiteral::VarPart::appendTo(Glib::ustring & str) const
+VariableLiteral::VarPart::appendTo(ExecContext * ec, Glib::ustring & str) const
 {
-	str += (*this)().operator const Glib::ustring &();
+	str += (*this)(ec).operator const Glib::ustring &();
 }
-VariableLiteral::VarPart::operator VariableType() const
+VariableType
+VariableLiteral::VarPart::value(ExecContext * ec) const
 {
-	return (*this)();
+	return (*this)(ec);
 }
 
 DECLARE_COMPONENT_LOADER("literal", VariableLiteral, VariableLoader);
diff --git a/project2/common/variables/literal.h b/project2/common/variables/literal.h
index 4128d1c..8c120b6 100644
--- a/project2/common/variables/literal.h
+++ b/project2/common/variables/literal.h
@@ -8,28 +8,28 @@ class VariableLiteral : public VariableImpl {
 	public:
 		VariableLiteral(const Glib::ustring & src, const VT_typeID format = DefaultType);
 		VariableLiteral(ScriptNodePtr);
-		virtual VariableType value() const;
+		virtual VariableType value(ExecContext * ec) const;
 		class Part;
 		typedef boost::intrusive_ptr<Part> PartCPtr;
 		typedef std::list<PartCPtr> Vals;
 
 		class Part : public IntrusivePtrBase {
 			public:
-				virtual void appendTo(Glib::ustring & str) const = 0;
-				virtual operator VariableType() const = 0;
+				virtual void appendTo(ExecContext *, Glib::ustring & str) const = 0;
+				virtual VariableType value(ExecContext *) const = 0;
 		};
 		class TextPart : public Part {
 			public:
 				TextPart(const Glib::ustring & e);
-				void appendTo(Glib::ustring & str) const;
-				operator VariableType() const;
+				void appendTo(ExecContext *, Glib::ustring & str) const;
+				VariableType value(ExecContext *) const;
 				const Glib::ustring txt;
 		};
 		class VarPart : public Part, public Variable {
 			public:
 				VarPart(ScriptNodePtr e);
-				void appendTo(Glib::ustring & str) const;
-				operator VariableType() const;
+				void appendTo(ExecContext *, Glib::ustring & str) const;
+				VariableType value(ExecContext *) const;
 		};
 	private:
 		VariableType val;
diff --git a/project2/common/variables/localparam.cpp b/project2/common/variables/localparam.cpp
index 1b789a7..bb71bde 100644
--- a/project2/common/variables/localparam.cpp
+++ b/project2/common/variables/localparam.cpp
@@ -9,19 +9,19 @@ class VariableLocalParam : public VariableImplDyn {
 	public:
 		VariableLocalParam(ScriptNodePtr e) :
 			VariableImplDyn(e),
-			name(e->value("name").as<Glib::ustring>())
+			name(e->value("name", NULL).as<Glib::ustring>())
 		{
 		}
-		VariableType value() const
+		VariableType value(ExecContext * ec) const
 		{
 			try {
-				return IHaveParameters::getScopedParameter(name);
+				return IHaveParameters::getScopedParameter(name, ec);
 			}
 			catch (ParamNotFound) {
 				if (!defaultValue) {
 					throw;
 				}
-				return (*defaultValue)();
+				return (*defaultValue)(ec);
 			}
 		}
 	private:
diff --git a/project2/common/variables/lookup.cpp b/project2/common/variables/lookup.cpp
index 2a96338..b3f9002 100644
--- a/project2/common/variables/lookup.cpp
+++ b/project2/common/variables/lookup.cpp
@@ -33,38 +33,38 @@ class VariableLookup : public VariableImplDyn, public RowProcessor {
 		VariableLookup(ScriptNodePtr e) :
 			VariableImplDyn(e),
 			RowProcessor(e),
-			name(e->value("name").as<Glib::ustring>())
+			name(e->value("name", NULL).as<Glib::ustring>())
 		{
 			e->script->loader.addLoadTarget(e, Storer::into<ElementLoader>(&rowSets));
 		}
-		VariableType value() const
+		VariableType value(ExecContext * ec) const
 		{
 			if (map.empty()) {
-				fillCache();
+				fillCache(ec);
 			}
 			Key k;
 			k.reserve(parameters.size());
 			BOOST_FOREACH(const Parameters::value_type & p, parameters) {
-				k.push_back(p.second);
+				k.push_back(p.second(ec));
 			}
 			return safeMapLookup<NotFound>(map, k);
 		}
 	private:
-		void fillCache() const
+		void fillCache(ExecContext * ec) const
 		{
 			BOOST_FOREACH(const RowSets::value_type & rs, rowSets) {
-				rs->execute(filter, this);
+				rs->execute(filter, boost::bind(&VariableLookup::rowReady, this, _1, ec), ec);
 			}
 			Logger()->messagef(LOG_DEBUG, "%s: %s has filled cached with %zu items",
 					__PRETTY_FUNCTION__, name.c_str(), map.size());
 		}
-		void rowReady(const RowState * rs) const
+		void rowReady(const RowState * rs, ExecContext * ec) const
 		{
 			Key k;
 			BOOST_FOREACH(const Parameters::value_type & p, parameters) {
-				k.push_back(rs->getCurrentValue(p.first));
+				k.push_back(rs->getCurrentValue(ec, p.first));
 			}
-			map[k] = rs->getCurrentValue(name);
+			map[k] = rs->getCurrentValue(ec, name);
 		}
 		mutable Map map;
 		typedef ANONSTORAGEOF(RowSet) RowSets;
diff --git a/project2/common/variables/param.cpp b/project2/common/variables/param.cpp
index 7292b0a..a1ef9b7 100644
--- a/project2/common/variables/param.cpp
+++ b/project2/common/variables/param.cpp
@@ -1,31 +1,31 @@
 #include <pch.hpp>
+#include "../execContext.h"
 #include "../variables.h"
 #include "../scriptLoader.h"
 #include "../scriptStorage.h"
-#include "../appEngine.h"
 
 /// Variable implementation to access call parameters
 class VariableParam : public VariableImplDyn {
 	public:
 		VariableParam(ScriptNodePtr e) :
 			VariableImplDyn(e),
-			name(e->value("name").as<Glib::ustring>())
+			name(e->value("name", NULL))
 		{
 		}
-		VariableType value() const
+		VariableType value(ExecContext * ec) const
 		{
 			try {
-				return ApplicationEngine::getCurrent()->env()->getParamQuery(name);
+				return ec->getParameter(name);
 			}
 			catch (ParamNotFound) {
 				if (!defaultValue) {
 					throw;
 				}
-				return (*defaultValue)();
+				return (*defaultValue)(ec);
 			}
 		}
 	private:
-		const Glib::ustring name;
+		const VariableType name;
 };
 DECLARE_COMPONENT_LOADER("param", VariableParam, VariableLoader);
 
diff --git a/project2/common/variables/session.cpp b/project2/common/variables/session.cpp
index fc33d8e..ed2077d 100644
--- a/project2/common/variables/session.cpp
+++ b/project2/common/variables/session.cpp
@@ -1,27 +1,27 @@
 #include <pch.hpp>
 #include "../variables.h"
+#include "../execContext.h"
 #include "../scriptLoader.h"
 #include "../scriptStorage.h"
-#include "../appEngine.h"
 
 /// Variable implementation to access session contents
 class VariableSession : public VariableImplDyn {
 	public:
 		VariableSession(ScriptNodePtr e) :
 			VariableImplDyn(e),
-			name(e->value("name").as<Glib::ustring>())
+			name(e->value("name", NULL).as<Glib::ustring>())
 		{
 		}
-		VariableType value() const
+		VariableType value(ExecContext * ec) const
 		{
 			try {
-				return ApplicationEngine::getCurrent()->session()->GetValue(name);
+				return ec->getSession()->GetValue(name);
 			}
 			catch (Session::VariableNotFound) {
 				if (!defaultValue) {
 					throw;
 				}
-				return (*defaultValue)();
+				return (*defaultValue)(ec);
 			}
 		}
 	private:
diff --git a/project2/common/view.h b/project2/common/view.h
index 75a0f3c..52a4130 100644
--- a/project2/common/view.h
+++ b/project2/common/view.h
@@ -5,6 +5,7 @@
 #include "scriptStorage.h"
 
 class MultiRowSetPresenter;
+class ExecContext;
 SimpleMessageException(EmptyRequiredRows);
 
 /// Base class for Project2 components that output data
@@ -13,7 +14,7 @@ class View : public virtual SourceObject {
 		View(ScriptNodePtr);
 		virtual ~View();
 
-		virtual void execute(const MultiRowSetPresenter *) const = 0;
+		virtual void execute(const MultiRowSetPresenter *, ExecContext *) const = 0;
 };
 
 #endif
diff --git a/project2/common/viewGroup.cpp b/project2/common/viewGroup.cpp
index b01f6c8..e6e84d0 100644
--- a/project2/common/viewGroup.cpp
+++ b/project2/common/viewGroup.cpp
@@ -11,11 +11,11 @@ class ViewGroup : public View {
 			s->script->loader.addLoadTarget(s, Storer::into<ElementLoader>(&subViews));
 		}
 
-		void execute(const MultiRowSetPresenter * presenter) const
+		void execute(const MultiRowSetPresenter * presenter, ExecContext * ec) const
 		{
 			presenter->addNewRowSet(name);
 			BOOST_FOREACH(const SubViews::value_type & sq, subViews) {
-				sq->execute(presenter);
+				sq->execute(presenter, ec);
 			}
 			presenter->finishRowSet();
 		}
diff --git a/project2/common/viewHost.cpp b/project2/common/viewHost.cpp
index 04e0d88..320e86d 100644
--- a/project2/common/viewHost.cpp
+++ b/project2/common/viewHost.cpp
@@ -17,14 +17,14 @@ ViewHost::~ViewHost()
 }
 
 void
-ViewHost::executeViews() const
+ViewHost::executeViews(ExecContext * ec) const
 {
 	loadScriptComponents();
 
-	MultiRowSetPresenterPtr presenter = getPresenter();
-	presenter->init();
+	MultiRowSetPresenterPtr presenter = getPresenter(ec);
+	presenter->init(ec);
 	BOOST_FOREACH(const Views::value_type & s, views) {
-		s->execute(presenter.get());
+		s->execute(presenter.get(), ec);
 	}
 	// Caches might open transactions
 	BOOST_FOREACH(const CommonObjects::DataSources::value_type & ds, CommonObjects::datasources) {
@@ -34,12 +34,12 @@ ViewHost::executeViews() const
 }
 
 void
-ViewHost::doTransforms() const
+ViewHost::doTransforms(ExecContext * ec) const
 {
-	MultiRowSetPresenterPtr presenter = getPresenter();
+	MultiRowSetPresenterPtr presenter = getPresenter(ec);
 	TransformSourcePtr ts = boost::dynamic_pointer_cast<TransformSource>(presenter);
 	if (ts) {
-		ts->doTransforms();
+		ts->doTransforms(ec);
 	}
 }
 
diff --git a/project2/common/viewHost.h b/project2/common/viewHost.h
index d09f1af..5ede3e4 100644
--- a/project2/common/viewHost.h
+++ b/project2/common/viewHost.h
@@ -13,11 +13,11 @@ class ViewHost : virtual public CheckHost, virtual public CommonObjects {
 		ViewHost(ScriptNodePtr script); 
 		~ViewHost();
 
-		void executeViews() const;
-		void doTransforms() const;
+		void executeViews(ExecContext *) const;
+		void doTransforms(ExecContext *) const;
 
 	protected:
-		virtual MultiRowSetPresenterPtr getPresenter() const = 0;
+		virtual MultiRowSetPresenterPtr getPresenter(ExecContext *) const = 0;
 
 	private:
 		typedef ANONORDEREDSTORAGEOF(View) Views;