Add optional support for default values for variables

10 files changed, 93 insertions, 18 deletions

diff --git a/project2/appEngine.h b/project2/appEngine.h
index 7f37cfd..54a8cec 100644
--- a/project2/appEngine.h
+++ b/project2/appEngine.h
@@ -8,6 +8,8 @@
 
 class ApplicationEngine {
 	public:
+		class UriElementOutOfRange : std::exception { };
+		class ParamNotFound : std::exception { };
 		class DataSourceNotFound : std::exception { };
 		class DataSourceNotCompatible : std::exception { };
 
diff --git a/project2/cgiEnvironment.cpp b/project2/cgiEnvironment.cpp
index fe38f57..2faf165 100644
--- a/project2/cgiEnvironment.cpp
+++ b/project2/cgiEnvironment.cpp
@@ -1,4 +1,5 @@
 #include "cgiEnvironment.h"
+#include "appEngine.h"
 #include <map>
 #include <cgicc/Cgicc.h>
 #include <boost/tokenizer.hpp>
@@ -21,14 +22,21 @@ CgiEnvironment::~CgiEnvironment()
 }
 
 Glib::ustring
-CgiEnvironment::getParamUri(const std::string & p) const
+CgiEnvironment::getParamUri(unsigned int p) const
 {
-	return elems[atoi(p.c_str())];
+	if (p >= elems.size()) {
+		throw ApplicationEngine::UriElementOutOfRange();
+	}
+	return elems[p];
 }
 
 Glib::ustring
 CgiEnvironment::getParamQuery(const std::string & p) const
 {
+	cgicc::const_form_iterator i = cgi->getElement(p);
+	if (i == cgi->getElements().end()) {
+		throw ApplicationEngine::ParamNotFound();
+	}
 	return (*cgi)(p);
 }
 
diff --git a/project2/cgiEnvironment.h b/project2/cgiEnvironment.h
index 7df65c9..c01d50d 100644
--- a/project2/cgiEnvironment.h
+++ b/project2/cgiEnvironment.h
@@ -15,7 +15,7 @@ class CgiEnvironment : public Environment, public cgicc::CgiEnvironment {
 		CgiEnvironment(cgicc::Cgicc *);
 		virtual ~CgiEnvironment();
 
-		Glib::ustring getParamUri(const std::string & idx) const;
+		Glib::ustring getParamUri(unsigned int idx) const;
 		Glib::ustring getParamQuery(const std::string & idx) const;
 		std::string getServerName() const { return cgicc::CgiEnvironment::getServerName(); }
 		std::string getScriptName() const { return cgicc::CgiEnvironment::getScriptName(); }
diff --git a/project2/environment.cpp b/project2/environment.cpp
index 9e4d9f0..c0cc0fa 100644
--- a/project2/environment.cpp
+++ b/project2/environment.cpp
@@ -9,7 +9,7 @@ Environment::~Environment()
 }
 
 Glib::ustring
-Environment::getParamUri(const std::string &) const
+Environment::getParamUri(unsigned int) const
 {
 	throw ParameterTypeNotSupported();
 }
diff --git a/project2/environment.h b/project2/environment.h
index 2925f13..a8c6396 100644
--- a/project2/environment.h
+++ b/project2/environment.h
@@ -11,7 +11,7 @@ class Environment {
 		Environment();
 		virtual ~Environment() = 0;
 
-		virtual Glib::ustring getParamUri(const std::string & idx) const = 0;
+		virtual Glib::ustring getParamUri(unsigned int idx) const = 0;
 		virtual Glib::ustring getParamQuery(const std::string & idx) const = 0;
 
 		virtual std::string getServerName() const = 0;
diff --git a/project2/perRowValues.h b/project2/perRowValues.h
index 26a0a6b..cee7e07 100644
--- a/project2/perRowValues.h
+++ b/project2/perRowValues.h
@@ -15,6 +15,8 @@ class RowUser {
 
 class PerRowValues {
 	public:
+		class ParentOutOfRange : public std::exception { };
+		class FieldDoesNotExist : public std::exception { };
 		typedef std::vector<const PerRowValues *> RowValuesStack;
 		PerRowValues();
 		virtual ~PerRowValues() = 0;
diff --git a/project2/session.h b/project2/session.h
index de31626..8dc1b8b 100644
--- a/project2/session.h
+++ b/project2/session.h
@@ -8,6 +8,7 @@
 
 class Session {
 	public:
+		class VariableNotFound : public std::exception { };
 		typedef std::map<Glib::ustring, Glib::ustring> Values;
 
 		Session();
diff --git a/project2/sessionShm.cpp b/project2/sessionShm.cpp
index c9f748c..e4c9d16 100644
--- a/project2/sessionShm.cpp
+++ b/project2/sessionShm.cpp
@@ -100,7 +100,11 @@ SessionShmData::~SessionShmData()
 Glib::ustring
 SessionShm::GetValue(const Glib::ustring & name) const
 {
-	return data->svs.find(name.c_str())->second.c_str();
+	SessionShmData::SessionValues::const_iterator i = data->svs.find(name.c_str());
+	if (i == data->svs.end()) {
+		throw Session::VariableNotFound();
+	}
+	return i->second.c_str();
 }
 
 void
diff --git a/project2/variables.cpp b/project2/variables.cpp
index 9aa1a5b..07d30aa 100644
--- a/project2/variables.cpp
+++ b/project2/variables.cpp
@@ -30,7 +30,15 @@ class VariableSession : public VariableImplDyn {
 		VariableSession(const Glib::ustring & src) : VariableImplDyn(src) { }
 		const Glib::ustring & value() const
 		{
-			cache = ApplicationEngine::getCurrent()->session()->GetValue(source.substr(1));
+			try {
+				cache = ApplicationEngine::getCurrent()->session()->GetValue(name);
+			}
+			catch (Session::VariableNotFound) {
+				if (!defaultValue) {
+					throw;
+				}
+				cache = *defaultValue;
+			}
 			return cache;
 		}
 };
@@ -41,7 +49,15 @@ class VariableParam : public VariableImplDyn {
 		const Glib::ustring & value() const
 		{
 			if (!cacheValid) {
-				cache = ApplicationEngine::getCurrent()->env()->getParamQuery(source.substr(1));
+				try {
+					cache = ApplicationEngine::getCurrent()->env()->getParamQuery(name);
+				}
+				catch (ApplicationEngine::ParamNotFound) {
+					if (!defaultValue) {
+						throw;
+					}
+					cache = *defaultValue;
+				}
 				cacheValid = true;
 			}
 			return cache;
@@ -54,7 +70,15 @@ class VariableUri : public VariableImplDyn {
 		const Glib::ustring & value() const
 		{
 			if (!cacheValid) {
-				cache = ApplicationEngine::getCurrent()->env()->getParamUri(source.substr(1));
+				try {
+					cache = ApplicationEngine::getCurrent()->env()->getParamUri(atoi(name.c_str()));
+				}
+				catch (ApplicationEngine::UriElementOutOfRange) {
+					if (!defaultValue) {
+						throw;
+					}
+					cache = *defaultValue;
+				}
 				cacheValid = true;
 			}
 			return cache;
@@ -73,16 +97,33 @@ class VariableParent : public VariableImplDyn, public RowUser {
 		const Glib::ustring & value() const
 		{
 			if (!cacheValid) {
-				if (!row) {
-					PerRowValues::RowValuesStack::const_reverse_iterator r = PerRowValues::Stack().rbegin();
-					for (size_t p = depth; --p; r++) ;
-					row = *r;
-					row->use(this);
-					if (dep) {
-						row->use(dep);
+				try {
+					if (!row) {
+						PerRowValues::RowValuesStack::const_reverse_iterator r = PerRowValues::Stack().rbegin();
+						for (size_t p = depth; --p; r++) ;
+						if (r == PerRowValues::Stack().rend()) {
+							throw PerRowValues::ParentOutOfRange();
+						}
+						row = *r;
+						row->use(this);
+						if (dep) {
+							row->use(dep);
+						}
 					}
+					cache = row->getCurrentValue(source);
+				}
+				catch (PerRowValues::ParentOutOfRange) {
+					if (!defaultValue) {
+						throw;
+					}
+					cache = *defaultValue;
+				}
+				catch (PerRowValues::FieldDoesNotExist) {
+					if (!defaultValue) {
+						throw;
+					}
+					cache = *defaultValue;
 				}
-				cache = row->getCurrentValue(source);
 				cacheValid = true;
 			}
 			return cache;
@@ -170,3 +211,17 @@ Variable::create(const Glib::ustring & s, RowUser * dep)
 	}
 }
 
+VariableImpl::VariableImpl(const Glib::ustring & src) :
+	source(src)
+{
+	Glib::ustring::const_iterator nameStart = std::find_if(source.begin(), source.end(), Glib::Unicode::isalnum);
+	Glib::ustring::const_iterator nameEnd = std::find(nameStart, source.end(), '|');
+	name = Glib::ustring(nameStart, nameEnd);
+	Glib::ustring::const_iterator defaultStart = nameEnd;
+	if (defaultStart != source.end()) {
+		defaultStart++;
+		Glib::ustring::const_iterator defaultEnd = source.end();
+		defaultValue = Glib::ustring(defaultStart, defaultEnd);
+	}
+}
+
diff --git a/project2/variables.h b/project2/variables.h
index 3387a0a..ae3d3c6 100644
--- a/project2/variables.h
+++ b/project2/variables.h
@@ -2,6 +2,7 @@
 #define VARIABLES_H
 
 #include <boost/shared_ptr.hpp>
+#include <boost/optional.hpp>
 #include <glibmm/ustring.h>
 #include <libxml++/nodes/element.h>
 #include <libxml++/attribute.h>
@@ -13,8 +14,10 @@ class VariableImpl {
 		virtual const Glib::ustring & value() const = 0;
 
 	protected:
-		VariableImpl(const Glib::ustring & src) : source(src) { }
+		VariableImpl(const Glib::ustring & src);
 		const Glib::ustring source;
+		Glib::ustring name;
+		boost::optional<Glib::ustring> defaultValue;
 };
 
 class Variable {