Add id() and is_a() functions to entity_instance class Make filename argument to open() function optional

src/ifcparse/IfcUntypedEntity.cpp

@@ -30,6 +30,13 @@ IfcParse::IfcUntypedEntity::IfcUntypedEntity(IfcAbstractEntity* e) {
 	entity = e;
 	_type = e->type();
 }
+unsigned int IfcParse::IfcUntypedEntity::id() const {
+	if (entity->file) {
+		return static_cast<unsigned int>(entity->id());
+	} else {
+		throw IfcException("Entity not bound to a file");
+	}
+}
 bool IfcParse::IfcUntypedEntity::is(IfcSchema::Type::Enum v) const {
 	IfcSchema::Type::Enum _ty = _type;
 	if (v == _ty) return true;

src/ifcparse/IfcUntypedEntity.h

@@ -17,10 +17,13 @@ namespace IfcParse {
 	public:
 		IfcUntypedEntity(const std::string& s);
 		IfcUntypedEntity(IfcAbstractEntity* e);
+		
 		bool is(IfcSchema::Type::Enum v) const;
 		IfcSchema::Type::Enum type() const;	
 		bool is_a(const std::string& s) const;
 		std::string is_a() const;
+
+		unsigned int id() const;
 		unsigned int getArgumentCount() const;
 		IfcUtil::ArgumentType getArgumentType(unsigned int i) const;
 		ArgumentPtr getArgument(unsigned int i) const;

src/ifcwrap/Interface.h

@@ -17,10 +17,13 @@ namespace IfcParse {
 		IfcSchema::Type::Enum _type;
 	public:
 		IfcUntypedEntity(const std::string& s);
+		
 		bool is(IfcSchema::Type::Enum v) const;
 		IfcSchema::Type::Enum type() const;	
 		bool is_a(const std::string& s) const;
 		std::string is_a() const;
+
+		unsigned int id() const;
 		unsigned int getArgumentCount() const;
 		IfcUtil::ArgumentType getArgumentType(unsigned int i) const;
 		ArgumentPtr getArgument(unsigned int i) const;

src/ifcwrap/ifc.py

@@ -43,12 +43,14 @@ class entity_instance:
 		self.wrapped_data.set_argument(idx, entity_instance.map_value(value))
 	def __len__(self): return len(self.wrapped_data)
 	def __repr__(self): return repr(self.wrapped_data)
+	def is_a(self, *args): return self.wrapped_data.is_a(*args)
+	def id(self): return self.wrapped_data.id()
 
 
 class file:
 	instances = []
-	def __init__(self, f):
-		self.wrapped_data = f
+	def __init__(self, f=None):
+		self.wrapped_data = f or ifc_wrapper.file()
 	def create_entity(self,type,*args,**kwargs):
 		e = entity_instance(ifc_wrapper.entity_instance(type))
 		attrs = list(enumerate(args)) + \
@@ -94,8 +96,8 @@ class guid:
 		return '{%s-%s-%s-%s-%s}'%(g[:8], g[8:12], g[12:16], g[16:20], g[20:])
 
 
-def open(fn):
-	return file(ifc_wrapper.open(fn))
+def open(fn=None):
+	return file(ifc_wrapper.open(fn)) if fn else file()
 
 def create_shape(inst, settings): return ifc_wrapper.create_shape(inst.wrapped_data, settings)