X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftrunk%2Fsrc%2Fsynfig%2Floadcanvas.cpp;h=200456ee4969b9e43edc06b16dcd7a0b2d02b052;hb=756c0d29ac1742f231e6615f9a577e574e35a4af;hp=f4a91c84ec31cca996a1943cb7222655d1bcd27d;hpb=bf92e1e2c959ab1fb668fa5a8274004a6f30a140;p=synfig.git

diff --git a/synfig-core/trunk/src/synfig/loadcanvas.cpp b/synfig-core/trunk/src/synfig/loadcanvas.cpp
index f4a91c8..200456e 100644
--- a/synfig-core/trunk/src/synfig/loadcanvas.cpp
+++ b/synfig-core/trunk/src/synfig/loadcanvas.cpp
@@ -6,6 +6,7 @@
 **
 **	\legal
 **	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**	Copyright (c) 2007, 2008 Chris Moore
 **
 **	This package is free software; you can redistribute it and/or
 **	modify it under the terms of the GNU General Public License as
@@ -87,6 +88,8 @@ test_class test_class_instance;
 
 /* === M A C R O S ========================================================= */
 
+#define VALUENODE_COMPATIBILITY_URL "http://synfig.org/Convert#Compatibility"
+
 inline bool is_whitespace(char x) { return ((x)=='\n' || (x)=='\t' || (x)==' '); }
 
 /* === P R O C E D U R E S ================================================= */
@@ -290,6 +293,15 @@ CanvasParser::parse_integer(xmlpp::Element *element)
 	return atoi(val.c_str());
 }
 
+// see 'minor hack' at the end of parse_vector() below
+// making this 'static' to give it file local scope
+// stops it working (where working means working around
+// bug #1509627)
+Vector &canvas_parser_vector_id(Vector &vector)
+{
+	return vector;
+}
+
 Vector
 CanvasParser::parse_vector(xmlpp::Element *element)
 {
@@ -332,7 +344,12 @@ CanvasParser::parse_vector(xmlpp::Element *element)
 		else
 			error_unexpected_element(child,child->get_name());
 	}
-	return vect;
+	// Minor hack - gcc 4.1.2 and earlier think that we're not using
+	// 'vect' and optimize it out at -O2 and higher.  This convinces
+	// them that we are really using it.
+	return canvas_parser_vector_id(vect);
+	// When the bug is fixed, we can just do this instead:
+	// return vect;
 }
 
 Color
@@ -841,7 +858,6 @@ CanvasParser::parse_value(xmlpp::Element *element,Canvas::Handle canvas)
 		return ValueBase(parse_canvas(element,canvas,true));
 	else
 	{
-		DEBUGPOINT();
 		error_unexpected_element(element,element->get_name());
 	}
 
@@ -874,7 +890,7 @@ CanvasParser::parse_animated(xmlpp::Element *element,Canvas::Handle canvas)
 
 	if(!value_node)
 	{
-		error(element,strprintf(_("Unable to create <animated> with type \"%s\""),ValueBase::type_name(type).c_str()));
+		error(element,strprintf(_("Unable to create <animated> with type \"%s\""),ValueBase::type_local_name(type).c_str()));
 		return ValueNode_Animated::Handle();
 	}
 
@@ -1036,390 +1052,177 @@ CanvasParser::parse_animated(xmlpp::Element *element,Canvas::Handle canvas)
 		else
 			error_unexpected_element(child,child->get_name());
 	}
-	value_node->changed();
-	return value_node;
-}
-
-handle<ValueNode_Subtract>
-CanvasParser::parse_subtract(xmlpp::Element *element,Canvas::Handle canvas)
-{
-	assert(element->get_name()=="subtract");
 
-	handle<ValueNode_Subtract> value_node;
-	handle<ValueNode> lhs,rhs,scalar;
+	// in canvas version 0.1, angles used to wrap, so to get from -179
+	// degrees to 180 degrees meant a 1 degree change
+	// in canvas version 0.2 they don't, so that's a 359 degree change
 
-	if(element->get_attribute("type"))
-	{
-		ValueBase::Type type=ValueBase::ident_type(element->get_attribute("type")->get_value());
-
-		if(!type)
-		{
-			error(element,"Bad type in <subtract>");
-			return ValueNode_Subtract::Handle();
-		}
-		value_node=ValueNode_Subtract::create(type);
-	}
-	else
-		value_node=ValueNode_Subtract::create();
-
-	if(!value_node)
+	// when loading a version 0.1 canvas, modify constant angle
+	// waypoints to that they are within 180 degrees of the previous
+	// waypoint's value
+	if (type == ValueBase::TYPE_ANGLE) 
 	{
-		error(element,strprintf(_("Unable to create <subtract>")));
-		return handle<ValueNode_Subtract>();
-	}
-
-	//if(element->get_attribute("scalar"))
-	//{
-	//	value_node->set_scalar(atof(element->get_attribute("scalar")->get_value().c_str()));
-	//}
-
-	try
-	{
-		if(element->get_attribute("scalar"))
-		{
-			// This is for compatibility with older versions of the file format
-			String value(element->get_attribute("scalar")->get_value());
-			if((value[0]<='9' && value[0]>='0')	 || value[0]=='-')
-			{
-				warning(element, _("Use of a real value where the ID should be is deprecated"));
-				value_node->set_scalar(atof(value.c_str()));
-			}
-			else
-				value_node->set_scalar(canvas->surefind_value_node(value));
-			scalar=value_node->get_scalar();
-		}
-
-		if(element->get_attribute("lhs"))
-		{
-			lhs=canvas->surefind_value_node(element->get_attribute("lhs")->get_value());
-			value_node->set_lhs(lhs);
-		}
-
-		if(element->get_attribute("rhs"))
-		{
-			rhs=canvas->surefind_value_node(element->get_attribute("rhs")->get_value());
-			value_node->set_rhs(rhs);
-		}
-	}
-	catch (Exception::IDNotFound)
-	{
-		error(element,"attribute in <subtract> references unknown ID");
-	}
-	catch (Exception::FileNotFound)
-	{
-		error(element,"Unable to open external file referenced in ID");
-	}
-
-	xmlpp::Element::NodeList list = element->get_children();
-	for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
-	{
-		xmlpp::Element *child(dynamic_cast<xmlpp::Element*>(*iter));
-		if(!child)
-			continue;
-		else
-		if(child->get_name()=="lhs")
-		{
-			if(lhs)
-			{
-				error(child,"LHS component of <subtract> already defined!");
-				continue;
-			}
-
-			xmlpp::Element::NodeList list = child->get_children();
-			xmlpp::Element::NodeList::iterator iter;
-
-			// Search for the first non-text XML element
-			for(iter = list.begin(); iter != list.end(); ++iter)
-				if(dynamic_cast<xmlpp::Element*>(*iter)) break;
-
-			if(iter==list.end())
-			{
-				error(child,_("<lhs> is missing its contents"));
-				continue;
-			}
-
-			lhs=parse_value_node(dynamic_cast<xmlpp::Element*>(*iter),canvas);
-
-			if(lhs)
-				value_node->set_lhs(lhs);
-			else
-			{
-				error((*iter),"Parse of LHS ValueNode failed");
-			}
-
-			// \todo do a search for more elements and warn if they are found
-		}
-		else
-		if(child->get_name()=="rhs")
+		if (canvas->get_version() == "0.1")
 		{
-			if(rhs)
-			{
-				error(child,"RHS component of <subtract> already defined!");
-				continue;
-			}
-
-			xmlpp::Element::NodeList list = child->get_children();
-			xmlpp::Element::NodeList::iterator iter;
-
-			// Search for the first non-text XML element
-			for(iter = list.begin(); iter != list.end(); ++iter)
-				if(dynamic_cast<xmlpp::Element*>(*iter)) break;
-
-			if(iter==list.end())
-			{
-				error(child,_("<rhs> is missing its contents"));
-				continue;
-			}
-
-			rhs=parse_value_node(dynamic_cast<xmlpp::Element*>(*iter),canvas);
-
-			if(rhs)
-				value_node->set_rhs(rhs);
-			else
-			{
-				error((*iter),"Parse of RHS ValueNode failed");
-			}
-
-			// \todo do a search for more elements and warn if they are found
-		}
-		else
-		if(child->get_name()=="scalar")
-		{
-			if(scalar)
-			{
-				error(child,"scalar component of <subtract> already defined!");
-				continue;
-			}
-
-			xmlpp::Element::NodeList list = child->get_children();
-			xmlpp::Element::NodeList::iterator iter;
-
-			// Search for the first non-text XML element
-			for(iter = list.begin(); iter != list.end(); ++iter)
-				if(dynamic_cast<xmlpp::Element*>(*iter)) break;
-
-			if(iter==list.end())
-			{
-				error(child,_("<scalar> is missing its contents"));
-				continue;
-			}
-
-			scalar=parse_value_node(dynamic_cast<xmlpp::Element*>(*iter),canvas);
-
-			if(scalar)
-				value_node->set_scalar(scalar);
-			else
-			{
-				error((*iter),"Parse of scalar ValueNode failed");
+			bool first = true;
+			Real angle, prev = 0;
+			WaypointList &wl = value_node->waypoint_list();
+			for (WaypointList::iterator iter = wl.begin(); iter != wl.end(); iter++)
+			{
+				angle = Angle::deg(iter->get_value(iter->get_time()).get(Angle())).get();
+				if (first)
+					first = false;
+				else if (iter->get_value_node()->get_name() == "constant")
+				{
+					if (angle - prev > 180)
+					{
+						while (angle - prev > 180) angle -= 360;
+						iter->set_value(Angle::deg(angle));
+					}
+					else if (prev - angle > 180)
+					{
+						while (prev - angle > 180) angle += 360;
+						iter->set_value(Angle::deg(angle));
+					}
+				}
+				prev = angle;
 			}
-
-			// \todo do a search for more elements and warn if they are found
 		}
-		else
-			error_unexpected_element(child,child->get_name());
 	}
 
-	if(!value_node->get_rhs() || !value_node->get_lhs() || !value_node->get_scalar())
-		error(element,"<subtract> is missing LHS, RHS, or SCALAR");
-
-	if(value_node->get_rhs() == value_node->get_lhs())
-		warning(element,"LHS is equal to RHS in <subtract>, so this value_node will always be zero!");
-
+	value_node->changed();
 	return value_node;
 }
 
 etl::handle<LinkableValueNode>
 CanvasParser::parse_linkable_value_node(xmlpp::Element *element,Canvas::Handle canvas)
 {
-	handle<LinkableValueNode> value_node;
-	ValueBase::Type type;
-
 	// Determine the type
-	if(element->get_attribute("type"))
+	if(!element->get_attribute("type"))
 	{
-		type=ValueBase::ident_type(element->get_attribute("type")->get_value());
-
-		if(!type)
-		{
-			error(element,"Bad type in ValueNode");
-			return 0;
-		}
+		error(element, strprintf(_("Missing attribute \"type\" in <%s>"), element->get_name().c_str()));
+		return 0;
 	}
-	else
+
+	ValueBase::Type type=ValueBase::ident_type(element->get_attribute("type")->get_value());
+
+	if(!type)
 	{
-		error(element,"Missing type in ValueNode");
+		error(element, strprintf(_("Bad type in <%s>"), element->get_name().c_str()));
 		return 0;
 	}
 
-	value_node=LinkableValueNode::create(element->get_name(),type);
+	handle<LinkableValueNode> value_node=LinkableValueNode::create(element->get_name(),type);
+ 	handle<ValueNode> c[value_node->link_count()];
 
 	if(!value_node)
 	{
-		error(element,"Unknown ValueNode type "+element->get_name());
+		error(element, strprintf(_("Error creating ValueNode <%s> with type '%s'.  Refer to '%s'"),
+								 element->get_name().c_str(),
+								 ValueBase::type_local_name(type).c_str(),
+								 VALUENODE_COMPATIBILITY_URL));
 		return 0;
 	}
 
 	if(value_node->get_type()!=type)
 	{
-		error(element,"ValueNode did not accept type");
+		error(element, strprintf(_("<%s> did not accept type '%s'"),
+								 element->get_name().c_str(),
+								 ValueBase::type_local_name(type).c_str()));
 		return 0;
 	}
 
 	value_node->set_root_canvas(canvas->get_root());
 
-	int i;
-	for(i=0;i<value_node->link_count();i++)
+	// handle exported valuenodes
 	{
-		if(element->get_attribute(value_node->link_name(i)))
-		try {
-			String id(element->get_attribute(value_node->link_name(i))->get_value());
-
-			if(!value_node->set_link(i,
-					canvas->surefind_value_node(
-						id
-					)
-				)
-			) error(element,strprintf(_("Unable to set link \"%s\" to ValueNode \"%s\" (link #%d in \"%s\")"),value_node->link_name(i).c_str(),id.c_str(),i,value_node->get_name().c_str()));
-		}
-		catch(Exception::IDNotFound)
-		{
-			error(element,"Unable to resolve "+element->get_attribute(value_node->link_name(i))->get_value());
-		}
-		catch(Exception::FileNotFound)
+		int index;
+		String id, name;
+		xmlpp::Element::AttributeList attrib_list(element->get_attributes());
+		for(xmlpp::Element::AttributeList::iterator iter = attrib_list.begin(); iter != attrib_list.end(); iter++)
 		{
-			error(element,"Unable to open file referenced in "+element->get_attribute(value_node->link_name(i))->get_value());
-		}
-		catch(...)
-		{
-			error(element,strprintf(_("Unknown Exception thrown when referencing ValueNode \"%s\""),
-				element->get_attribute(value_node->link_name(i))->get_value().c_str()));
-			throw;
-		}
-	}
+			name = (*iter)->get_name();
+			id = (*iter)->get_value();
 
+			if (name == "guid" || name == "id" || name == "type")
+				continue;
 
+			try {
+				index = value_node->get_link_index_from_name(name);
 
-	xmlpp::Element::NodeList list = element->get_children();
-	for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
-	{
-		xmlpp::Element *child(dynamic_cast<xmlpp::Element*>(*iter));
-		try
-		{
-			if(!child)
-				continue;
-			int index=value_node->get_link_index_from_name(child->get_name());
+				if(c[index])
+				{
+					error(element,strprintf(_("'%s' was already defined in <%s>"),
+											name.c_str(),
+											element->get_name().c_str()));
+					continue;
+				}
 
-			xmlpp::Element::NodeList list = child->get_children();
-			xmlpp::Element::NodeList::iterator iter;
+				c[index] = canvas->surefind_value_node(id);
 
-			// Search for the first non-text XML element
-			for(iter = list.begin(); iter != list.end(); ++iter)
-				if(dynamic_cast<xmlpp::Element*>(*iter)) break;
+				if (!c[index])
+				{
+					error(element, strprintf(_("'%s' attribute in <%s> references unknown ID '%s'"),
+											 name.c_str(),
+											 element->get_name().c_str(),
+											 id.c_str()));
+					continue;
+				}
 
-			if(iter==list.end())
+				if(!value_node->set_link(index, c[index]))
+				{
+					error(element, strprintf(_("Unable to set link '\"%s\" to ValueNode \"%s\" (link #%d in \"%s\")"),
+											 value_node->link_name(index).c_str(),
+											 id.c_str(),
+											 index,
+											 element->get_name().c_str()));
+					continue;
+				}
+
+				// printf("  <%s> set link %d (%s) using exported value\n", element->get_name().c_str(), index, name.c_str());
+			}
+			catch (Exception::BadLinkName)
 			{
-				error(child,_("element is missing its contents"));
-				continue;
+				warning(element, strprintf("Bad link name '%s'", name.c_str()));
 			}
-
-			ValueNode::Handle link=parse_value_node(dynamic_cast<xmlpp::Element*>(*iter),canvas);
-
-			if(!link)
+			catch(Exception::IDNotFound)
 			{
-				error((*iter),"Parse of ValueNode failed");
+				error(element,"Unable to resolve " + id);
 			}
-			else
-			if(!value_node->set_link(index,link))
+			catch(Exception::FileNotFound)
 			{
-				//error(dynamic_cast<xmlpp::Element*>(*iter),strprintf("Unable to connect value node ('%s' of type '%s') to link %d",link->get_name().c_str(),ValueBase::type_name(link->get_type()).c_str(),index));
-				error(element,strprintf("Unable to connect value node ('%s' of type '%s') to link %d",link->get_name().c_str(),ValueBase::type_name(link->get_type()).c_str(),index));
+				error(element,"Unable to open file referenced in " + id);
 			}
-
-			// \todo do a search for more elements and warn if they are found
-
-		}
-		catch(Exception::BadLinkName)
-		{
-			error_unexpected_element(child,child->get_name());
-		}
-		catch(...)
-		{
-			error(child,strprintf(_("Unknown Exception thrown when working on element \"%s\""),child->get_name().c_str()));
-			throw;
-		}
-	}
-
-	return value_node;
-}
-
-handle<ValueNode_Composite>
-CanvasParser::parse_composite(xmlpp::Element *element,Canvas::Handle canvas)
-{
-	assert(element->get_name()=="composite");
-
-	if(!element->get_attribute("type"))
-	{
-		error(element,"Missing attribute \"type\" in <composite>");
-		return handle<ValueNode_Composite>();
-	}
-
-	ValueBase::Type type=ValueBase::ident_type(element->get_attribute("type")->get_value());
-
-	if(!type)
-	{
-		error(element,"Bad type in <composite>");
-		return handle<ValueNode_Composite>();
-	}
-
-	handle<ValueNode_Composite> value_node=ValueNode_Composite::create(type);
-	handle<ValueNode> c[6];
-
-	if(!value_node)
-	{
-		error(element,strprintf(_("Unable to create <composite>")));
-		return handle<ValueNode_Composite>();
-	}
-
-	int i;
-
-	for(i=0;i<value_node->link_count();i++)
-	{
-		string name=strprintf("c%d",i+1);
-		if(c[i])
-		{
-			error(element,name+" was already defined in <composite>");
-			continue;
-		}
-		if(element->get_attribute(name))
-		{
-			c[i]=canvas->surefind_value_node(element->get_attribute(name)->get_value());
-			if(c[i])
+			catch(...)
 			{
-				if(!value_node->set_link(i,c[i]))
-				{
-					error(element,'"'+name+"\" attribute in <composite> has bad type");
-				}
+				error(element,strprintf(_("Unknown Exception thrown when referencing ValueNode \"%s\""), id.c_str()));
+				throw;
 			}
-			else
-				error(element,'"'+name+"\" attribute in <composite> references unknown ID");
 		}
 	}
 
-	xmlpp::Element::NodeList list = element->get_children();
-	for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
+	// handle inline valuenodes
 	{
-		xmlpp::Element *child(dynamic_cast<xmlpp::Element*>(*iter));
-		if(!child)
-			continue;
-		else
-		for(i=0;i<value_node->link_count();i++)
+		int index;
+		String child_name;
+		xmlpp::Element::NodeList list = element->get_children();
+		for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
 		{
-			string name=strprintf("c%d",i+1);
-			if(child->get_name()==name)
+			xmlpp::Element *child(dynamic_cast<xmlpp::Element*>(*iter));
+			try
 			{
-				if(c[i])
+				if(!child)
+					continue;
+
+				child_name = child->get_name();
+
+				index = value_node->get_link_index_from_name(child_name);
+
+				if(c[index])
 				{
-					error(child,name+" was already defined in <composite>");
+					error(child, strprintf(_("'%s' was already defined in <%s>"),
+										   child_name.c_str(),
+										   element->get_name().c_str()));
 					break;
 				}
 
@@ -1432,63 +1235,60 @@ CanvasParser::parse_composite(xmlpp::Element *element,Canvas::Handle canvas)
 
 				if(iter==list.end())
 				{
-					error(child,strprintf(_("<%s> is missing its contents"),name.c_str()));
-					break;
+					error(child,strprintf(_("element <%s> is missing its contents"),
+										  child_name.c_str()));
+					continue;
 				}
 
-				c[i]=parse_value_node(dynamic_cast<xmlpp::Element*>(*iter),canvas);
+				c[index]=parse_value_node(dynamic_cast<xmlpp::Element*>(*iter),canvas);
 
-				if(!c[i])
+				if(!c[index])
 				{
-					error((*iter),"Parse of "+name+" ValueNode failed");
-					break;
+					error((*iter),strprintf(_("Parse of '%s' failed"),
+											child_name.c_str()));
+					continue;
 				}
 
-				if(!value_node->set_link(i,c[i]))
+				if(!value_node->set_link(index,c[index]))
 				{
-					error(child,strprintf(_("<%s> has a bad value"),name.c_str()));
-					break;
+					error(child,strprintf(_("Unable to connect value node ('%s' of type '%s') to link %d (%s)"),
+										  c[index]->get_name().c_str(),
+										  ValueBase::type_local_name(c[index]->get_type()).c_str(),
+										  index,
+										  value_node->link_name(index).c_str()));
+					continue;
 				}
 
 				// \todo do a search for more elements and warn if they are found
-				break;
+
+				// printf("  <%s> set link %d (%s) using inline value\n", element->get_name().c_str(), index, child_name.c_str());
+			}
+			catch(Exception::BadLinkName)
+			{
+				warning(child, strprintf("Bad link name for <%s>", element->get_name().c_str()));
+			}
+			catch(...)
+			{
+				error(child, strprintf(_("Unknown Exception thrown when working on element \"%s\""),child_name.c_str()));
+				throw;
 			}
 		}
-		// somewhat of a hack, but it works
-		if(i==value_node->link_count()) error_unexpected_element(child,child->get_name());
 	}
 
-	switch(value_node->link_count())
+	for (int i = 0; i < value_node->link_count(); i++)
 	{
-	case 1:
-		if(!value_node->get_link(0))
-		{
-			error(element,"<composite> is missing parameters");
-			return handle<ValueNode_Composite>();
-		}
-		break;
-	case 2:
-		if(!value_node->get_link(0) ||!value_node->get_link(1))
-		{
-			error(element,"<composite> is missing parameters");
-			return handle<ValueNode_Composite>();
-		}
-		break;
-	case 3:
-		if(!value_node->get_link(0) ||!value_node->get_link(1) ||!value_node->get_link(2))
-		{
-			error(element,"<composite> is missing parameters");
-			return handle<ValueNode_Composite>();
-		}
-		break;
-	case 4:
-		if(!value_node->get_link(0) ||!value_node->get_link(1) ||!value_node->get_link(2) ||!value_node->get_link(3))
+		if (!c[i] &&
+			// the 'width' parameter of <stripes> wasn't always present, so it won't be in old .sif files
+			!(element->get_name() == "stripes" && value_node->link_name(i) == "width"))
 		{
-			error(element,"<composite> is missing parameters");
-			return handle<ValueNode_Composite>();
+			error(element, strprintf(_("<%s> is missing link %d (%s)"),
+									 element->get_name().c_str(),
+									 i,
+									 value_node->link_name(i).c_str()));
+ 			return 0;
 		}
-		break;
-    }
+	}
+
 	return value_node;
 }
 
@@ -1723,7 +1523,7 @@ CanvasParser::parse_value_node(xmlpp::Element *element,Canvas::Handle canvas)
 			return value_node;
 	}
 
-	// If ValueBase::ident_type() recognises the name, then we know it's a ValueBase
+	// If ValueBase::ident_type() recognizes the name, then we know it's a ValueBase
 	if(element->get_name()!="canvas" && ValueBase::ident_type(element->get_name()))
 	{
 		ValueBase data=parse_value(element,canvas);
@@ -1745,12 +1545,6 @@ CanvasParser::parse_value_node(xmlpp::Element *element,Canvas::Handle canvas)
 	if(element->get_name()=="hermite" || element->get_name()=="animated")
 		value_node=parse_animated(element,canvas);
 	else
-	if(element->get_name()=="subtract")
-		value_node=parse_subtract(element,canvas);
-	else
-	if(element->get_name()=="composite")
-		value_node=parse_composite(element,canvas);
-	else
 	if(element->get_name()=="dynamic_list")
 		value_node=parse_dynamic_list(element,canvas);
 	else
@@ -1758,20 +1552,23 @@ CanvasParser::parse_value_node(xmlpp::Element *element,Canvas::Handle canvas)
 		value_node=parse_dynamic_list(element,canvas);
 	else
 	if(LinkableValueNode::book().count(element->get_name()))
+	{
 		value_node=parse_linkable_value_node(element,canvas);
+		if (!value_node) value_node = PlaceholderValueNode::create();
+	}
 	else
 	if(element->get_name()=="canvas")
 		value_node=ValueNode_Const::create(parse_canvas(element,canvas,true));
 	else
 	{
 		error_unexpected_element(element,element->get_name());
-		error(element, "Expected a ValueNode");
+		error(element, strprintf(_("Expected a ValueNode.  Refer to '%s'"),
+								 VALUENODE_COMPATIBILITY_URL));
+		value_node=PlaceholderValueNode::create();
 	}
 
-
 	value_node->set_root_canvas(canvas->get_root());
 
-
 	// If we were successful, and our element has
 	// an ID attribute, go ahead and add it to the
 	// value_node list
@@ -1850,7 +1647,7 @@ CanvasParser::parse_layer(xmlpp::Element *element,Canvas::Handle canvas)
 	{
 		String version(element->get_attribute("version")->get_value());
 		if(version>layer->get_version())
-			warning(element,_("Installed layer version is larger than layer version in file"));
+			warning(element,_("Installed layer version is smaller than layer version in file"));
 		if(version!=layer->get_version())
 			layer->set_version(version);
 	}
@@ -1897,7 +1694,9 @@ CanvasParser::parse_layer(xmlpp::Element *element,Canvas::Handle canvas)
 
 				String str=	child->get_attribute("use")->get_value();
 
-				if(layer->get_param(param_name).get_type()==ValueBase::TYPE_CANVAS)
+				if (str.empty())
+					error(child,_("Empty use=\"\" value in <param>"));
+				else if(layer->get_param(param_name).get_type()==ValueBase::TYPE_CANVAS)
 				{
 					if(!layer->set_param(param_name,canvas->surefind_canvas(str)))
 						error((*iter),_("Layer rejected canvas link"));
@@ -1932,7 +1731,7 @@ CanvasParser::parse_layer(xmlpp::Element *element,Canvas::Handle canvas)
 				continue;
 			}
 
-			// If we recognise the element name as a
+			// If we recognize the element name as a
 			// ValueBase, then treat is at one
 			if(/*(*iter)->get_name()!="canvas" && */ValueBase::ident_type((*iter)->get_name()) && !dynamic_cast<xmlpp::Element*>(*iter)->get_attribute("guid"))
 			{
@@ -2031,6 +1830,11 @@ CanvasParser::parse_canvas(xmlpp::Element *element,Canvas::Handle parent,bool in
 			canvas->set_guid(guid);
 	}
 
+	if(element->get_attribute("version"))
+		canvas->set_version(element->get_attribute("version")->get_value());
+	else if(parent)
+		canvas->set_version(parent->get_version());
+
 	if(element->get_attribute("width"))
 		canvas->rend_desc().set_w(atoi(element->get_attribute("width")->get_value().c_str()));
 
@@ -2165,7 +1969,7 @@ CanvasParser::parse_canvas(xmlpp::Element *element,Canvas::Handle parent,bool in
 
 				// If we don't have any name, warn
 				if(list.empty())
-					warning(child,_("blank \"name\" entitity"));
+					warning(child,_("blank \"name\" entity"));
 
 				string tmp;
 				for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
@@ -2180,7 +1984,7 @@ CanvasParser::parse_canvas(xmlpp::Element *element,Canvas::Handle parent,bool in
 
 				// If we don't have any description, warn
 				if(list.empty())
-					warning(child,_("blank \"desc\" entitity"));
+					warning(child,_("blank \"desc\" entity"));
 
 				string tmp;
 				for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
@@ -2195,7 +1999,7 @@ CanvasParser::parse_canvas(xmlpp::Element *element,Canvas::Handle parent,bool in
 
 				// If we don't have any description, warn
 				if(list.empty())
-					warning(child,_("blank \"author\" entitity"));
+					warning(child,_("blank \"author\" entity"));
 
 				string tmp;
 				for(xmlpp::Element::NodeList::iterator iter = list.begin(); iter != list.end(); ++iter)
@@ -2220,9 +2024,20 @@ CanvasParser::parse_canvas(xmlpp::Element *element,Canvas::Handle parent,bool in
 
 	if(canvas->value_node_list().placeholder_count())
 	{
-		error(element,strprintf(_("Canvas %s has undefined ValueNodes"),canvas->get_id().c_str()));
+		String nodes;
+		for (ValueNodeList::const_iterator iter = canvas->value_node_list().begin(); iter != canvas->value_node_list().end(); iter++)
+			if(PlaceholderValueNode::Handle::cast_dynamic(*iter))
+			{
+				if (nodes != "") nodes += ", ";
+				nodes += "'" + (*iter)->get_id() + "'";
+			}
+		error(element,strprintf(_("Canvas '%s' has undefined %s: %s"),
+								canvas->get_id().c_str(),
+								canvas->value_node_list().placeholder_count() == 1 ? _("ValueNode") : _("ValueNodes"),
+								nodes.c_str()));
 	}
 
+	canvas->set_version(CURRENT_CANVAS_VERSION);
 	return canvas;
 }
 
@@ -2235,7 +2050,6 @@ CanvasParser::parse_from_file(const String &file)
 Canvas::Handle
 CanvasParser::parse_from_file_as(const String &file_,const String &as_)
 {
-	CHECK_EXPIRE_TIME();
 	try
 	{
         ChangeLocale change_locale(LC_NUMERIC, "C");
@@ -2296,8 +2110,6 @@ CanvasParser::parse_from_file_as(const String &file_,const String &as_)
 Canvas::Handle
 CanvasParser::parse_from_string(const String &data)
 {
-	CHECK_EXPIRE_TIME();
-
 	try
 	{
         ChangeLocale change_locale(LC_NUMERIC, "C");