Report subject with errors to client for more meaningful error messages.

git-svn-id: http://svn.drobilla.net/lad/trunk/ingen@4556 a436a847-0d15-0410-975c-d299462d15a1

21 files changed, 100 insertions, 99 deletions

diff --git a/src/bindings/Client.hpp b/src/bindings/Client.hpp
index f8dd84ff..248c71ec 100644
--- a/src/bindings/Client.hpp
+++ b/src/bindings/Client.hpp
@@ -31,7 +31,7 @@ public:
 
 	void bundle_begin() {}
 	void bundle_end() {}
-	void response(int32_t id, Status status) {}
+	void response(int32_t id, Status status, const std::string& subject) {}
 	void error(const std::string& msg) {}
 	void put(const Raul::URI& path, const Ingen::Resource::Properties& properties) {}
 	void connect(const Raul::Path& src_port_path, const Raul::Path& dst_port_path) {}
diff --git a/src/gui/App.cpp b/src/gui/App.cpp
index a815c6e7..1d6381fb 100644
--- a/src/gui/App.cpp
+++ b/src/gui/App.cpp
@@ -203,10 +203,14 @@ App::serialiser()
 }
 
 void
-App::response(int32_t id, Status status)
+App::response(int32_t id, Status status, const std::string& subject)
 {
 	if (status) {
-		error_message(ingen_status_string(status));
+		std::string msg = ingen_status_string(status);
+		if (!subject.empty()) {
+			msg += ": " + subject;
+		}
+		error_message(msg);
 	}
 }
 
diff --git a/src/gui/App.hpp b/src/gui/App.hpp
index 7969982c..1f611a13 100644
--- a/src/gui/App.hpp
+++ b/src/gui/App.hpp
@@ -140,7 +140,7 @@ protected:
 	explicit App(Ingen::Shared::World* world);
 
 	bool animate();
-	void response(int32_t id, Ingen::Status status);
+	void response(int32_t id, Ingen::Status status, const std::string& subject);
 
 	void property_change(const Raul::URI&  subject,
 	                     const Raul::URI&  key,
diff --git a/src/gui/ConnectWindow.hpp b/src/gui/ConnectWindow.hpp
index 00ba5fd3..ca27787e 100644
--- a/src/gui/ConnectWindow.hpp
+++ b/src/gui/ConnectWindow.hpp
@@ -51,7 +51,9 @@ public:
 
 	void set_connected_to(SharedPtr<Ingen::Interface> engine);
 	void start(App& app, Ingen::Shared::World* world);
-	void ingen_response(int32_t id, Status status) { _attached = true; }
+	void ingen_response(int32_t id, Status status, const std::string& subject) {
+		_attached = true;
+	}
 
 	bool attached()  const { return _finished_connecting; }
 	bool quit_flag() const { return _quit_flag; }
diff --git a/src/server/Broadcaster.hpp b/src/server/Broadcaster.hpp
index 2c88c5f8..32a1ab92 100644
--- a/src/server/Broadcaster.hpp
+++ b/src/server/Broadcaster.hpp
@@ -106,7 +106,7 @@ public:
 
 	void set_response_id(int32_t id) {} ///< N/A
 	void get(const Raul::URI& uri) {} ///< N/A
-	void response(int32_t id, Status status) {} ///< N/A
+	void response(int32_t id, Status status, const std::string& subject) {} ///< N/A
 
 	void error(const std::string& msg) { BROADCAST(error, msg); }
 
diff --git a/src/server/Event.hpp b/src/server/Event.hpp
index 963671ab..5f2e99bb 100644
--- a/src/server/Event.hpp
+++ b/src/server/Event.hpp
@@ -78,13 +78,6 @@ public:
 	/** Return the status (success or error code) of this event. */
 	Status status() const { return _status; }
 
-	/** Respond to the originating client. */
-	void respond(Status status) {
-		if (_request_client) {
-			_request_client->response(_request_id, status);
-		}
-	}
-
 protected:
 	Event(Engine& engine, SharedPtr<Interface> client, int32_t id, FrameTime time)
 		: _engine(engine)
@@ -107,12 +100,27 @@ protected:
 		return !st;
 	}
 
+	inline bool pre_process_done(Status st, const Raul::URI& subject) {
+		_status      = st;
+		_err_subject = subject.str();
+		return !st;
+	}
+
+	/** Respond to the originating client. */
+	inline Status respond() {
+		if (_request_client) {
+			_request_client->response(_request_id, _status, _err_subject);
+		}
+		return _status;
+	}
+
 	Engine&                _engine;
 	Raul::AtomicPtr<Event> _next;
 	SharedPtr<Interface>   _request_client;
 	int32_t                _request_id;
 	FrameTime              _time;
 	Status                 _status;
+	std::string            _err_subject;
 };
 
 } // namespace Server
diff --git a/src/server/EventWriter.hpp b/src/server/EventWriter.hpp
index 2a080be4..d25dc113 100644
--- a/src/server/EventWriter.hpp
+++ b/src/server/EventWriter.hpp
@@ -84,7 +84,7 @@ public:
 
 	virtual void get(const Raul::URI& uri);
 
-	virtual void response(int32_t id, Status status) {}  ///< N/A
+	virtual void response(int32_t id, Status status, const std::string& subject) {}  ///< N/A
 
 	virtual void error(const std::string& msg) {}  ///< N/A
 
diff --git a/src/server/events/Connect.cpp b/src/server/events/Connect.cpp
index b9ea148a..dc6f7b99 100644
--- a/src/server/events/Connect.cpp
+++ b/src/server/events/Connect.cpp
@@ -57,30 +57,32 @@ Connect::pre_process()
 
 	PortImpl* tail = _engine.engine_store()->find_port(_tail_path);
 	PortImpl* head = _engine.engine_store()->find_port(_head_path);
-	if (!tail || !head) {
-		return Event::pre_process_done(PORT_NOT_FOUND);
+	if (!tail) {
+		return Event::pre_process_done(PORT_NOT_FOUND, _tail_path.str());
+	} else if (!head) {
+		return Event::pre_process_done(PORT_NOT_FOUND, _head_path.str());
 	}
 
 	_dst_input_port  = dynamic_cast<InputPort*>(head);
 	_src_output_port = dynamic_cast<OutputPort*>(tail);
 	if (!_dst_input_port || !_src_output_port) {
-		return Event::pre_process_done(DIRECTION_MISMATCH);
+		return Event::pre_process_done(DIRECTION_MISMATCH, _head_path.str());
 	}
 
 	NodeImpl* const src_node = tail->parent_node();
 	NodeImpl* const dst_node = head->parent_node();
 	if (!src_node || !dst_node) {
-		return Event::pre_process_done(PARENT_NOT_FOUND);
+		return Event::pre_process_done(PARENT_NOT_FOUND, _head_path.str());
 	}
 
 	if (src_node->parent() != dst_node->parent()
 	    && src_node != dst_node->parent()
 	    && src_node->parent() != dst_node) {
-		return Event::pre_process_done(PARENT_DIFFERS);
+		return Event::pre_process_done(PARENT_DIFFERS, _head_path.str());
 	}
 
 	if (!EdgeImpl::can_connect(_src_output_port, _dst_input_port)) {
-		return Event::pre_process_done(TYPE_MISMATCH);
+		return Event::pre_process_done(TYPE_MISMATCH, _head_path);
 	}
 
 	if (src_node->parent_patch() != dst_node->parent_patch()) {
@@ -100,7 +102,7 @@ Connect::pre_process()
 	}
 
 	if (_patch->has_edge(_src_output_port, _dst_input_port)) {
-		return Event::pre_process_done(EXISTS);
+		return Event::pre_process_done(EXISTS, _head_path);
 	}
 
 	_edge = SharedPtr<EdgeImpl>(
@@ -151,8 +153,7 @@ Connect::execute(ProcessContext& context)
 void
 Connect::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->connect(_tail_path, _head_path);
 	}
 }
diff --git a/src/server/events/CreateNode.cpp b/src/server/events/CreateNode.cpp
index 76f29613..b8e795e8 100644
--- a/src/server/events/CreateNode.cpp
+++ b/src/server/events/CreateNode.cpp
@@ -61,16 +61,16 @@ CreateNode::pre_process()
 	}
 
 	if (_engine.engine_store()->find_object(_path)) {
-		return Event::pre_process_done(EXISTS);
+		return Event::pre_process_done(EXISTS, _path.str());
 	}
 
 	if (!(_patch = _engine.engine_store()->find_patch(_path.parent()))) {
-		return Event::pre_process_done(PARENT_NOT_FOUND);
+		return Event::pre_process_done(PARENT_NOT_FOUND, _path.parent().str());
 	}
 
 	PluginImpl* plugin = _engine.node_factory()->plugin(_plugin_uri);
 	if (!plugin) {
-		return Event::pre_process_done(PLUGIN_NOT_FOUND);
+		return Event::pre_process_done(PLUGIN_NOT_FOUND, _plugin_uri);
 	}
 
 	const iterator p = _properties.find(uris.ingen_polyphonic);
@@ -84,7 +84,7 @@ CreateNode::pre_process()
 	                                  polyphonic,
 	                                  _patch,
 	                                  _engine))) {
-		return Event::pre_process_done(CREATION_FAILED);
+		return Event::pre_process_done(CREATION_FAILED, _path.str());
 	}
 
 	_node->properties().insert(_properties.begin(), _properties.end());
@@ -125,8 +125,7 @@ CreateNode::execute(ProcessContext& context)
 void
 CreateNode::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		for (Update::const_iterator i = _update.begin(); i != _update.end(); ++i) {
 			_engine.broadcaster()->put(i->first, i->second);
 		}
diff --git a/src/server/events/CreatePatch.cpp b/src/server/events/CreatePatch.cpp
index b6b62f71..602fe2a4 100644
--- a/src/server/events/CreatePatch.cpp
+++ b/src/server/events/CreatePatch.cpp
@@ -48,14 +48,14 @@ bool
 CreatePatch::pre_process()
 {
 	if (_path.is_root() || _engine.engine_store()->find_object(_path) != NULL) {
-		return Event::pre_process_done(EXISTS);
+		return Event::pre_process_done(EXISTS, _path);
 	}
 
 	const Raul::Path& path = (const Raul::Path&)_path;
 
 	_parent = _engine.engine_store()->find_patch(path.parent());
 	if (!_parent) {
-		return Event::pre_process_done(PARENT_NOT_FOUND);
+		return Event::pre_process_done(PARENT_NOT_FOUND, path.parent());
 	}
 
 	const Ingen::Shared::URIs& uris = _engine.world()->uris();
@@ -70,7 +70,7 @@ CreatePatch::pre_process()
 	}
 
 	if (int_poly < 1) {
-		return Event::pre_process_done(INVALID_POLY);
+		return Event::pre_process_done(INVALID_POLY, path);
 	}
 
 	if (int_poly == _parent->internal_poly()) {
@@ -114,8 +114,7 @@ CreatePatch::execute(ProcessContext& context)
 void
 CreatePatch::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->put(_path, _update);
 	}
 }
diff --git a/src/server/events/CreatePort.cpp b/src/server/events/CreatePort.cpp
index 9ddb8894..b89a90cc 100644
--- a/src/server/events/CreatePort.cpp
+++ b/src/server/events/CreatePort.cpp
@@ -85,15 +85,15 @@ bool
 CreatePort::pre_process()
 {
 	if (_port_type == PortType::UNKNOWN) {
-		return Event::pre_process_done(UNKNOWN_TYPE);
+		return Event::pre_process_done(UNKNOWN_TYPE, _path);
 	}
 
 	if (_engine.engine_store()->find_object(_path)) {
-		return Event::pre_process_done(_status);
+		return Event::pre_process_done(_status, _path);
 	}
 
 	if (!(_patch = _engine.engine_store()->find_patch(_path.parent()))) {
-		return Event::pre_process_done(PARENT_NOT_FOUND);
+		return Event::pre_process_done(PARENT_NOT_FOUND, _path.parent());
 	}
 
 	const Shared::URIs&  uris           = _engine.world()->uris();
@@ -112,7 +112,7 @@ CreatePort::pre_process()
 			               _engine.world()->forge().make(old_n_ports)));
 	} else if (index_i->second.type() != uris.forge.Int ||
 	           index_i->second.get_int32() != old_n_ports) {
-		return Event::pre_process_done(BAD_INDEX);
+		return Event::pre_process_done(BAD_INDEX, _path);
 	}
 
 	const PropIter poly_i = _properties.find(uris.ingen_polyphonic);
@@ -123,7 +123,7 @@ CreatePort::pre_process()
 	if (!(_patch_port = _patch->create_port(
 		      *_engine.buffer_factory(), _path.symbol(),
 		      _port_type, _buf_type, buf_size, _is_output, polyphonic))) {
-		return Event::pre_process_done(CREATION_FAILED);
+		return Event::pre_process_done(CREATION_FAILED, _path);
 	}
 
 	_patch_port->properties().insert(_properties.begin(), _properties.end());
@@ -174,8 +174,7 @@ CreatePort::execute(ProcessContext& context)
 void
 CreatePort::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->put(_path, _update);
 	}
 
diff --git a/src/server/events/Delete.cpp b/src/server/events/Delete.cpp
index 7ef4d2a5..9c68f4fe 100644
--- a/src/server/events/Delete.cpp
+++ b/src/server/events/Delete.cpp
@@ -63,8 +63,10 @@ Delete::~Delete()
 bool
 Delete::pre_process()
 {
-	if (_path.is_root() || _path == "path:/control_in" || _path == "path:/control_out") {
-		return Event::pre_process_done(NOT_DELETABLE);
+	if (_path.is_root() ||
+	    _path == "path:/control_in" ||
+	    _path == "path:/control_out") {
+		return Event::pre_process_done(NOT_DELETABLE, _path);
 	}
 
 	_lock.acquire();
@@ -157,13 +159,7 @@ Delete::post_process()
 {
 	_lock.release();
 	_removed_bindings.reset();
-
-	if (!Raul::Path::is_path(_uri)
-	    || _path.is_root() || _path == "path:/control_in" || _path == "path:/control_out") {
-		// XXX: Report error?  Silently ignore?
-	} else if (!_node && !_port) {
-		respond(NOT_FOUND);
-	} else if (_patch_node_listnode || _patch_port_listnode) {
+	if (!respond() && (_patch_node_listnode || _patch_port_listnode)) {
 		if (_patch_node_listnode) {
 			_node->deactivate();
 			delete _patch_node_listnode;
@@ -171,15 +167,12 @@ Delete::post_process()
 			delete _patch_port_listnode;
 		}
 
-		respond(SUCCESS);
 		_engine.broadcaster()->bundle_begin();
 		if (_disconnect_event) {
 			_disconnect_event->post_process();
 		}
 		_engine.broadcaster()->del(_path);
 		_engine.broadcaster()->bundle_end();
-	} else {
-		respond(FAILURE);
 	}
 
 	if (_engine_port) {
diff --git a/src/server/events/Delta.cpp b/src/server/events/Delta.cpp
index 8da4b230..0f067a7e 100644
--- a/src/server/events/Delta.cpp
+++ b/src/server/events/Delta.cpp
@@ -113,7 +113,7 @@ Delta::pre_process()
 		: static_cast<Shared::ResourceImpl*>(_engine.node_factory()->plugin(_subject));
 
 	if (!_object && (!is_graph_object || !_create)) {
-		return Event::pre_process_done(NOT_FOUND);
+		return Event::pre_process_done(NOT_FOUND, _subject);
 	}
 
 	const Ingen::Shared::URIs& uris = _engine.world()->uris();
@@ -139,7 +139,7 @@ Delta::pre_process()
 			// Grab the object for applying properties, if the create-event succeeded
 			_object = _engine.engine_store()->find_object(Raul::Path(_subject.str()));
 		} else {
-			return Event::pre_process_done(BAD_OBJECT_TYPE);
+			return Event::pre_process_done(BAD_OBJECT_TYPE, _subject);
 		}
 	}
 
@@ -250,7 +250,8 @@ Delta::pre_process()
 		_types.push_back(op);
 	}
 
-	return Event::pre_process_done(_status == NOT_PREPARED ? SUCCESS : _status);
+	return Event::pre_process_done(_status == NOT_PREPARED ? SUCCESS : _status,
+	                               _subject);
 }
 
 void
@@ -346,7 +347,7 @@ Delta::post_process()
 		if (_create_event) {
 			_create_event->post_process();
 		} else {
-			respond(SUCCESS);
+			respond();
 			if (_create) {
 				_engine.broadcaster()->put(_subject, _properties, _context);
 			} else {
@@ -354,7 +355,7 @@ Delta::post_process()
 			}
 		}
 	} else {
-		respond(_status);
+		respond();
 	}
 }
 
diff --git a/src/server/events/Disconnect.cpp b/src/server/events/Disconnect.cpp
index 3ad9f650..00e4b374 100644
--- a/src/server/events/Disconnect.cpp
+++ b/src/server/events/Disconnect.cpp
@@ -119,14 +119,16 @@ Disconnect::pre_process()
 	if (_tail_path.parent().parent() != _head_path.parent().parent()
 	    && _tail_path.parent() != _head_path.parent().parent()
 	    && _tail_path.parent().parent() != _head_path.parent()) {
-		return Event::pre_process_done(PARENT_DIFFERS);
+		return Event::pre_process_done(PARENT_DIFFERS, _head_path);
 	}
 
 	_tail = _engine.engine_store()->find_port(_tail_path);
 	_head = _engine.engine_store()->find_port(_head_path);
 
-	if (_tail == NULL || _head == NULL) {
-		return Event::pre_process_done(PORT_NOT_FOUND);
+	if (!_tail) {
+		return Event::pre_process_done(PORT_NOT_FOUND, _tail_path);
+	} else if (!_head) {
+		return Event::pre_process_done(PORT_NOT_FOUND, _head_path);
 	}
 
 	NodeImpl* const src_node = _tail->parent_node();
@@ -151,11 +153,11 @@ Disconnect::pre_process()
 	assert(_patch);
 
 	if (!_patch->has_edge(_tail, _head)) {
-		return Event::pre_process_done(NOT_FOUND);
+		return Event::pre_process_done(NOT_FOUND, _head_path);
 	}
 
 	if (src_node == NULL || dst_node == NULL) {
-		return Event::pre_process_done(PARENT_NOT_FOUND);
+		return Event::pre_process_done(PARENT_NOT_FOUND, _head_path);
 	}
 
 	_impl = new Impl(_engine,
@@ -214,8 +216,7 @@ Disconnect::execute(ProcessContext& context)
 void
 Disconnect::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->disconnect(_tail->path(), _head->path());
 	}
 
diff --git a/src/server/events/DisconnectAll.cpp b/src/server/events/DisconnectAll.cpp
index d360073c..e1310251 100644
--- a/src/server/events/DisconnectAll.cpp
+++ b/src/server/events/DisconnectAll.cpp
@@ -89,17 +89,17 @@ DisconnectAll::pre_process()
 
 		_parent = _engine.engine_store()->find_patch(_parent_path);
 		if (!_parent) {
-			return Event::pre_process_done(PARENT_NOT_FOUND);
+			return Event::pre_process_done(PARENT_NOT_FOUND, _parent_path);
 		}
 
 		GraphObjectImpl* object = _engine.engine_store()->find_object(_path);
 		if (!object) {
-			return Event::pre_process_done(NOT_FOUND);
+			return Event::pre_process_done(NOT_FOUND, _path);
 		}
 
 		if (object->parent_patch() != _parent
 		    && object->parent()->parent_patch() != _parent) {
-			return Event::pre_process_done(INVALID_PARENT_PATH);
+			return Event::pre_process_done(INVALID_PARENT_PATH, _parent_path);
 		}
 
 		// Only one of these will succeed
@@ -159,8 +159,7 @@ DisconnectAll::execute(ProcessContext& context)
 void
 DisconnectAll::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->disconnect_all(_parent_path, _path);
 	}
 }
diff --git a/src/server/events/Get.cpp b/src/server/events/Get.cpp
index 24f3d1d9..cc64aaef 100644
--- a/src/server/events/Get.cpp
+++ b/src/server/events/Get.cpp
@@ -56,12 +56,14 @@ Get::pre_process()
 	if (_uri == "ingen:plugins") {
 		_plugins = _engine.node_factory()->plugins();
 		return Event::pre_process_done(SUCCESS);
+	} else if (_uri == "ingen:engine") {
+		return Event::pre_process_done(SUCCESS);
 	} else if (Raul::Path::is_valid(_uri.str())) {
 		_object = _engine.engine_store()->find_object(Raul::Path(_uri.str()));
-		return Event::pre_process_done(_object ? SUCCESS : NOT_FOUND);
+		return Event::pre_process_done(_object ? SUCCESS : NOT_FOUND, _uri);
 	} else {
 		_plugin = _engine.node_factory()->plugin(_uri);
-		return Event::pre_process_done(_plugin ? SUCCESS : NOT_FOUND);
+		return Event::pre_process_done(_plugin ? SUCCESS : NOT_FOUND, _uri);
 	}
 }
 
@@ -127,28 +129,17 @@ send_patch(Interface* client, const PatchImpl* patch)
 void
 Get::post_process()
 {
-	if (_uri == "ingen:plugins") {
-		respond(SUCCESS);
-		if (_request_client) {
+	if (!respond() && _request_client) {
+		if (_uri == "ingen:plugins") {
 			_engine.broadcaster()->send_plugins_to(_request_client.get(), _plugins);
-		}
-	} else if (_uri == "ingen:engine") {
-		respond(SUCCESS);
-		// TODO: Keep a proper RDF model of the engine
-		if (_request_client) {
+		} else if (_uri == "ingen:engine") {
+			// TODO: Keep a proper RDF model of the engine
 			Shared::URIs& uris = _engine.world()->uris();
 			_request_client->set_property(
 				uris.ingen_engine,
 				uris.ingen_sampleRate,
 				uris.forge.make(int32_t(_engine.driver()->sample_rate())));
-		}
-	} else if (!_object && !_plugin) {
-		respond(NOT_FOUND);
-	} else if (!_request_client) {
-		respond(CLIENT_NOT_FOUND);
-	} else {
-		respond(SUCCESS);
-		if (_object) {
+		} else if (_object) {
 			_request_client->bundle_begin();
 			const NodeImpl*  node  = NULL;
 			const PatchImpl* patch = NULL;
@@ -164,8 +155,8 @@ Get::post_process()
 		} else if (_plugin) {
 			_request_client->put(_uri, _plugin->properties());
 		}
-		_lock.release();
 	}
+	_lock.release();
 }
 
 } // namespace Events
diff --git a/src/server/events/Move.cpp b/src/server/events/Move.cpp
index 9a894e43..483c77e7 100644
--- a/src/server/events/Move.cpp
+++ b/src/server/events/Move.cpp
@@ -55,16 +55,16 @@ Move::pre_process()
 	Glib::RWLock::WriterLock lock(_engine.engine_store()->lock());
 
 	if (!_old_path.parent().is_parent_of(_new_path)) {
-		return Event::pre_process_done(PARENT_DIFFERS);
+		return Event::pre_process_done(PARENT_DIFFERS, _new_path);
 	}
 
 	_store_iterator = _engine.engine_store()->find(_old_path);
 	if (_store_iterator == _engine.engine_store()->end()) {
-		return Event::pre_process_done(NOT_FOUND);
+		return Event::pre_process_done(NOT_FOUND, _old_path);
 	}
 
 	if (_engine.engine_store()->find_object(_new_path)) {
-		return Event::pre_process_done(EXISTS);
+		return Event::pre_process_done(EXISTS, _new_path);
 	}
 
 	SharedPtr< Raul::Table< Raul::Path, SharedPtr<GraphObject> > > removed
@@ -106,8 +106,7 @@ Move::execute(ProcessContext& context)
 void
 Move::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->move(_old_path, _new_path);
 	}
 }
diff --git a/src/server/events/SetPortValue.cpp b/src/server/events/SetPortValue.cpp
index 673c9984..005974a2 100644
--- a/src/server/events/SetPortValue.cpp
+++ b/src/server/events/SetPortValue.cpp
@@ -57,7 +57,7 @@ bool
 SetPortValue::pre_process()
 {
 	if (_port->is_output()) {
-		return Event::pre_process_done(DIRECTION_MISMATCH);
+		return Event::pre_process_done(DIRECTION_MISMATCH, _port_path);
 	}
 
 	// Port is on a message context node, set value and run
@@ -129,8 +129,7 @@ SetPortValue::apply(Context& context)
 void
 SetPortValue::post_process()
 {
-	respond(_status);
-	if (!_status) {
+	if (!respond()) {
 		_engine.broadcaster()->set_property(
 			_port_path,
 			_engine.world()->uris().ingen_value,
diff --git a/src/shared/AtomReader.cpp b/src/shared/AtomReader.cpp
index 2bdd9fe1..862c61b1 100644
--- a/src/shared/AtomReader.cpp
+++ b/src/shared/AtomReader.cpp
@@ -261,7 +261,8 @@ AtomReader::write(const LV2_Atom* msg)
 			return false;
 		}
 		_iface.response(((LV2_Atom_Int*)request)->body,
-		                (Ingen::Status)((LV2_Atom_Int*)body)->body);
+		                (Ingen::Status)((LV2_Atom_Int*)body)->body,
+		                subject_uri);
 	} else {
 		Raul::warn << "Unknown object type <"
 		           << _map.unmap_uri(obj->body.otype)
diff --git a/src/shared/AtomWriter.cpp b/src/shared/AtomWriter.cpp
index 7d600466..80bd0156 100644
--- a/src/shared/AtomWriter.cpp
+++ b/src/shared/AtomWriter.cpp
@@ -272,7 +272,7 @@ AtomWriter::get(const Raul::URI& uri)
 }
 
 void
-AtomWriter::response(int32_t id, Status status)
+AtomWriter::response(int32_t id, Status status, const std::string& subject)
 {
 	if (id == -1) {
 		return;
@@ -282,6 +282,10 @@ AtomWriter::response(int32_t id, Status status)
 	lv2_atom_forge_blank(&_forge, &msg, next_id(), _uris.patch_Response);
 	lv2_atom_forge_property_head(&_forge, _uris.patch_request, 0);
 	lv2_atom_forge_int(&_forge, id);
+	if (!subject.empty() && Raul::URI::is_valid(subject)) {
+		lv2_atom_forge_property_head(&_forge, _uris.patch_subject, 0);
+		lv2_atom_forge_uri(&_forge, subject.c_str(), subject.length());
+	}
 	lv2_atom_forge_property_head(&_forge, _uris.patch_body, 0);
 	lv2_atom_forge_int(&_forge, status);
 	lv2_atom_forge_pop(&_forge, &msg);
diff --git a/src/shared/URIs.cpp b/src/shared/URIs.cpp
index b41a0db3..102c7b8b 100644
--- a/src/shared/URIs.cpp
+++ b/src/shared/URIs.cpp
@@ -75,6 +75,7 @@ URIs::URIs(Shared::Forge& f, URIMap* map)
 	, ingen_polyphony       (forge, map, NS_INGEN "polyphony")
 	, ingen_prototype       (forge, map, NS_INGEN "prototype")
 	, ingen_sampleRate      (forge, map, NS_INGEN "sampleRate")
+	, ingen_status          (forge, map, NS_INGEN "status")
 	, ingen_tail            (forge, map, NS_INGEN "tail")
 	, ingen_uiEmbedded      (forge, map, NS_INGEN "uiEmbedded")
 	, ingen_value           (forge, map, NS_INGEN "value")