1 files changed, 66 insertions, 11 deletions

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);
+	}
+}
+