Derive NodeMetaRef from MetaDataRef

9 files changed, 407 insertions, 232 deletions

diff --git a/.gitignore b/.gitignore
index d7e0daab4..c2600afeb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -74,6 +74,7 @@ locale/
 *.a
 *.ninja
 .ninja*
+*.gch
 
 ## Android build files
 build/android/src/main/assets
@@ -86,4 +87,3 @@ build/android/obj
 build/android/local.properties
 build/android/.gradle
 timestamp
-
diff --git a/build/android/jni/Android.mk b/build/android/jni/Android.mk
index 8f333c3d4..70a3d29c0 100644
--- a/build/android/jni/Android.mk
+++ b/build/android/jni/Android.mk
@@ -307,6 +307,7 @@ LOCAL_SRC_FILES += \
 		jni/src/script/lua_api/l_item.cpp         \
 		jni/src/script/lua_api/l_mainmenu.cpp     \
 		jni/src/script/lua_api/l_mapgen.cpp       \
+		jni/src/script/lua_api/l_metadata.cpp     \
 		jni/src/script/lua_api/l_nodemeta.cpp     \
 		jni/src/script/lua_api/l_nodetimer.cpp    \
 		jni/src/script/lua_api/l_noise.cpp        \
diff --git a/src/metadata.cpp b/src/metadata.cpp
index 8e04aa2d3..96453d710 100644
--- a/src/metadata.cpp
+++ b/src/metadata.cpp
@@ -37,12 +37,39 @@ bool Metadata::empty() const
 	return m_stringvars.size() == 0;
 }
 
-std::string Metadata::getString(const std::string &name,
-	u16 recursion) const
+size_t Metadata::size() const
+{
+	return m_stringvars.size();
+}
+
+bool Metadata::contains(const std::string &name) const
+{
+	return m_stringvars.find(name) != m_stringvars.end();
+}
+
+bool Metadata::operator==(const Metadata &other) const
+{
+	if (size() != other.size())
+		return false;
+
+	for (StringMap::const_iterator it = m_stringvars.begin();
+			it != m_stringvars.end(); ++it) {
+		if (!other.contains(it->first) ||
+				other.getString(it->first) != it->second)
+			return false;
+	}
+
+	return true;
+}
+
+const std::string &Metadata::getString(const std::string &name,
+		u16 recursion) const
 {
 	StringMap::const_iterator it = m_stringvars.find(name);
-	if (it == m_stringvars.end())
-		return "";
+	if (it == m_stringvars.end()) {
+		static const std::string empty_string = std::string("");
+		return empty_string;
+	}
 
 	return resolveString(it->second, recursion);
 }
@@ -56,14 +83,13 @@ void Metadata::setString(const std::string &name, const std::string &var)
 	}
 }
 
-std::string Metadata::resolveString(const std::string &str,
-	u16 recursion) const
+const std::string &Metadata::resolveString(const std::string &str,
+		u16 recursion) const
 {
-	if (recursion > 1) {
-		return str;
-	}
-	if (str.substr(0, 2) == "${" && str[str.length() - 1] == '}') {
+	if (recursion <= 1 &&
+			str.substr(0, 2) == "${" && str[str.length() - 1] == '}') {
 		return getString(str.substr(2, str.length() - 3), recursion + 1);
+	} else {
+		return str;
 	}
-	return str;
 }
diff --git a/src/metadata.h b/src/metadata.h
index a96bfc408..a629c0615 100644
--- a/src/metadata.h
+++ b/src/metadata.h
@@ -44,10 +44,10 @@ public:
 	bool empty() const;
 
 	// Generic key/value store
-	std::string getString(const std::string &name, u16 recursion = 0) const;
+	const std::string &getString(const std::string &name, u16 recursion = 0) const;
 	void setString(const std::string &name, const std::string &var);
 	// Support variable names in values
-	std::string resolveString(const std::string &str, u16 recursion = 0) const;
+	const std::string &resolveString(const std::string &str, u16 recursion = 0) const;
 	const StringMap &getStrings() const
 	{
 		return m_stringvars;
diff --git a/src/script/lua_api/CMakeLists.txt b/src/script/lua_api/CMakeLists.txt
index d507dcf70..efccce515 100644
--- a/src/script/lua_api/CMakeLists.txt
+++ b/src/script/lua_api/CMakeLists.txt
@@ -6,6 +6,7 @@ set(common_SCRIPT_LUA_API_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/l_inventory.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/l_item.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/l_mapgen.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/l_metadata.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/l_nodemeta.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/l_nodetimer.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/l_noise.cpp
@@ -22,4 +23,3 @@ set(common_SCRIPT_LUA_API_SRCS
 set(client_SCRIPT_LUA_API_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/l_mainmenu.cpp
 	PARENT_SCOPE)
-
diff --git a/src/script/lua_api/l_metadata.cpp b/src/script/lua_api/l_metadata.cpp
new file mode 100644
index 000000000..b54005bac
--- /dev/null
+++ b/src/script/lua_api/l_metadata.cpp
@@ -0,0 +1,252 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "lua_api/l_metadata.h"
+#include "lua_api/l_internal.h"
+#include "common/c_content.h"
+#include "serverenvironment.h"
+#include "map.h"
+#include "server.h"
+
+// LUALIB_API
+void *luaL_checkudata_is_metadataref(lua_State *L, int ud) {
+	void *p = lua_touserdata(L, ud);
+	if (p != NULL &&  // value is a userdata?
+			lua_getmetatable(L, ud)) {  // does it have a metatable?
+		lua_getfield(L, -1, "metadata_class");
+		if (lua_type(L, -1) == LUA_TSTRING) { // does it have a metadata_class field?
+			return p;
+		}
+	}
+	luaL_typerror(L, ud, "MetaDataRef");
+	return NULL;
+}
+
+MetaDataRef* MetaDataRef::checkobject(lua_State *L, int narg)
+{
+	luaL_checktype(L, narg, LUA_TUSERDATA);
+	void *ud = luaL_checkudata_is_metadataref(L, narg);
+	if (!ud)
+		luaL_typerror(L, narg, "MetaDataRef");
+
+	return *(MetaDataRef**)ud;  // unbox pointer
+}
+
+// Exported functions
+
+// get_string(self, name)
+int MetaDataRef::l_get_string(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	std::string name = luaL_checkstring(L, 2);
+
+	Metadata *meta = ref->getmeta(false);
+	if (meta == NULL) {
+		lua_pushlstring(L, "", 0);
+		return 1;
+	}
+
+	const std::string &str = meta->getString(name);
+	lua_pushlstring(L, str.c_str(), str.size());
+	return 1;
+}
+
+// set_string(self, name, var)
+int MetaDataRef::l_set_string(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	std::string name = luaL_checkstring(L, 2);
+	size_t len = 0;
+	const char *s = lua_tolstring(L, 3, &len);
+	std::string str(s, len);
+
+	Metadata *meta = ref->getmeta(!str.empty());
+	if (meta == NULL || str == meta->getString(name))
+		return 0;
+
+	meta->setString(name, str);
+	ref->reportMetadataChange();
+	return 0;
+}
+
+// get_int(self, name)
+int MetaDataRef::l_get_int(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	std::string name = lua_tostring(L, 2);
+
+	Metadata *meta = ref->getmeta(false);
+	if (meta == NULL) {
+		lua_pushnumber(L, 0);
+		return 1;
+	}
+
+	const std::string &str = meta->getString(name);
+	lua_pushnumber(L, stoi(str));
+	return 1;
+}
+
+// set_int(self, name, var)
+int MetaDataRef::l_set_int(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	std::string name = lua_tostring(L, 2);
+	int a = lua_tointeger(L, 3);
+	std::string str = itos(a);
+
+	Metadata *meta = ref->getmeta(true);
+	if (meta == NULL || str == meta->getString(name))
+		return 0;
+
+	meta->setString(name, str);
+	ref->reportMetadataChange();
+	return 0;
+}
+
+// get_float(self, name)
+int MetaDataRef::l_get_float(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	std::string name = lua_tostring(L, 2);
+
+	Metadata *meta = ref->getmeta(false);
+	if (meta == NULL) {
+		lua_pushnumber(L, 0);
+		return 1;
+	}
+
+	const std::string &str = meta->getString(name);
+	lua_pushnumber(L, stof(str));
+	return 1;
+}
+
+// set_float(self, name, var)
+int MetaDataRef::l_set_float(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	std::string name = lua_tostring(L, 2);
+	float a = lua_tonumber(L, 3);
+	std::string str = ftos(a);
+
+	Metadata *meta = ref->getmeta(true);
+	if (meta == NULL || str == meta->getString(name))
+		return 0;
+
+	meta->setString(name, str);
+	ref->reportMetadataChange();
+	return 0;
+}
+
+// to_table(self)
+int MetaDataRef::l_to_table(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+
+	Metadata *meta = ref->getmeta(true);
+	if (meta == NULL) {
+		lua_pushnil(L);
+		return 1;
+	}
+	lua_newtable(L);
+
+	ref->handleToTable(L, meta);
+
+	return 1;
+}
+
+// from_table(self, table)
+int MetaDataRef::l_from_table(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	MetaDataRef *ref = checkobject(L, 1);
+	int base = 2;
+
+	ref->clearMeta();
+
+	if (!lua_istable(L, base)) {
+		// No metadata
+		lua_pushboolean(L, true);
+		return 1;
+	}
+
+	// Create new metadata
+	Metadata *meta = ref->getmeta(true);
+	if (meta == NULL) {
+		lua_pushboolean(L, false);
+		return 1;
+	}
+
+	bool was_successful = ref->handleFromTable(L, base, meta);
+	ref->reportMetadataChange();
+	lua_pushboolean(L, was_successful);
+	return 1;
+}
+
+void MetaDataRef::handleToTable(lua_State *L, Metadata *meta)
+{
+	lua_newtable(L);
+	{
+		const StringMap &fields = meta->getStrings();
+		for (StringMap::const_iterator
+				it = fields.begin(); it != fields.end(); ++it) {
+			const std::string &name = it->first;
+			const std::string &value = it->second;
+			lua_pushlstring(L, name.c_str(), name.size());
+			lua_pushlstring(L, value.c_str(), value.size());
+			lua_settable(L, -3);
+		}
+	}
+	lua_setfield(L, -2, "fields");
+}
+
+bool MetaDataRef::handleFromTable(lua_State *L, int table, Metadata *meta)
+{
+	// Set fields
+	lua_getfield(L, table, "fields");
+	if (lua_istable(L, -1)) {
+		int fieldstable = lua_gettop(L);
+		lua_pushnil(L);
+		while (lua_next(L, fieldstable) != 0) {
+			// key at index -2 and value at index -1
+			std::string name = lua_tostring(L, -2);
+			size_t cl;
+			const char *cs = lua_tolstring(L, -1, &cl);
+			meta->setString(name, std::string(cs, cl));
+			lua_pop(L, 1); // Remove value, keep key for next iteration
+		}
+		lua_pop(L, 1);
+	}
+
+	return true;
+}
diff --git a/src/script/lua_api/l_metadata.h b/src/script/lua_api/l_metadata.h
new file mode 100644
index 000000000..561be6adf
--- /dev/null
+++ b/src/script/lua_api/l_metadata.h
@@ -0,0 +1,71 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+#ifndef L_METADATA_H_
+#define L_METADATA_H_
+
+#include "lua_api/l_base.h"
+#include "irrlichttypes_bloated.h"
+
+class Metadata;
+
+/*
+	NodeMetaRef
+*/
+
+class MetaDataRef : public ModApiBase {
+public:
+	virtual ~MetaDataRef() {}
+protected:
+	static MetaDataRef *checkobject(lua_State *L, int narg);
+
+	virtual void reportMetadataChange() {}
+	virtual Metadata* getmeta(bool auto_create) = 0;
+	virtual void clearMeta() = 0;
+
+	virtual void handleToTable(lua_State *L, Metadata *meta);
+	virtual bool handleFromTable(lua_State *L, int table, Metadata *meta);
+
+	// Exported functions
+
+	// get_string(self, name)
+	static int l_get_string(lua_State *L);
+
+	// set_string(self, name, var)
+	static int l_set_string(lua_State *L);
+
+	// get_int(self, name)
+	static int l_get_int(lua_State *L);
+
+	// set_int(self, name, var)
+	static int l_set_int(lua_State *L);
+
+	// get_float(self, name)
+	static int l_get_float(lua_State *L);
+
+	// set_float(self, name, var)
+	static int l_set_float(lua_State *L);
+
+	// to_table(self)
+	static int l_to_table(lua_State *L);
+
+	// from_table(self, table)
+	static int l_from_table(lua_State *L);
+};
+
+#endif /* L_NODEMETA_H_ */
diff --git a/src/script/lua_api/l_nodemeta.cpp b/src/script/lua_api/l_nodemeta.cpp
index 8391de03c..4b2b392da 100644
--- a/src/script/lua_api/l_nodemeta.cpp
+++ b/src/script/lua_api/l_nodemeta.cpp
@@ -36,7 +36,7 @@ NodeMetaRef* NodeMetaRef::checkobject(lua_State *L, int narg)
 	return *(NodeMetaRef**)ud;  // unbox pointer
 }
 
-NodeMetadata* NodeMetaRef::getmeta(bool auto_create)
+Metadata* NodeMetaRef::getmeta(bool auto_create)
 {
 	NodeMetadata *meta = m_env->getMap().getNodeMetadata(m_p);
 	if (meta == NULL && auto_create) {
@@ -49,17 +49,22 @@ NodeMetadata* NodeMetaRef::getmeta(bool auto_create)
 	return meta;
 }
 
-void NodeMetaRef::reportMetadataChange(NodeMetaRef *ref)
+void NodeMetaRef::clearMeta()
+{
+	m_env->getMap().removeNodeMetadata(m_p);
+}
+
+void NodeMetaRef::reportMetadataChange()
 {
 	// NOTE: This same code is in rollback_interface.cpp
 	// Inform other things that the metadata has changed
-	v3s16 blockpos = getNodeBlockPos(ref->m_p);
+	v3s16 blockpos = getNodeBlockPos(m_p);
 	MapEditEvent event;
 	event.type = MEET_BLOCK_NODE_METADATA_CHANGED;
 	event.p = blockpos;
-	ref->m_env->getMap().dispatchEvent(&event);
+	m_env->getMap().dispatchEvent(&event);
 	// Set the block to be saved
-	MapBlock *block = ref->m_env->getMap().getBlockNoCreateNoEx(blockpos);
+	MapBlock *block = m_env->getMap().getBlockNoCreateNoEx(blockpos);
 	if (block) {
 		block->raiseModified(MOD_STATE_WRITE_NEEDED,
 			MOD_REASON_REPORT_META_CHANGE);
@@ -75,115 +80,6 @@ int NodeMetaRef::gc_object(lua_State *L) {
 	return 0;
 }
 
-// get_string(self, name)
-int NodeMetaRef::l_get_string(lua_State *L)
-{
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	std::string name = luaL_checkstring(L, 2);
-
-	NodeMetadata *meta = ref->getmeta(false);
-	if(meta == NULL){
-		lua_pushlstring(L, "", 0);
-		return 1;
-	}
-	std::string str = meta->getString(name);
-	lua_pushlstring(L, str.c_str(), str.size());
-	return 1;
-}
-
-// set_string(self, name, var)
-int NodeMetaRef::l_set_string(lua_State *L)
-{
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	std::string name = luaL_checkstring(L, 2);
-	size_t len = 0;
-	const char *s = lua_tolstring(L, 3, &len);
-	std::string str(s, len);
-
-	NodeMetadata *meta = ref->getmeta(!str.empty());
-	if(meta == NULL || str == meta->getString(name))
-		return 0;
-	meta->setString(name, str);
-	reportMetadataChange(ref);
-	return 0;
-}
-
-// get_int(self, name)
-int NodeMetaRef::l_get_int(lua_State *L)
-{
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	std::string name = lua_tostring(L, 2);
-
-	NodeMetadata *meta = ref->getmeta(false);
-	if(meta == NULL){
-		lua_pushnumber(L, 0);
-		return 1;
-	}
-	std::string str = meta->getString(name);
-	lua_pushnumber(L, stoi(str));
-	return 1;
-}
-
-// set_int(self, name, var)
-int NodeMetaRef::l_set_int(lua_State *L)
-{
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	std::string name = lua_tostring(L, 2);
-	int a = lua_tointeger(L, 3);
-	std::string str = itos(a);
-
-	NodeMetadata *meta = ref->getmeta(true);
-	if(meta == NULL || str == meta->getString(name))
-		return 0;
-	meta->setString(name, str);
-	reportMetadataChange(ref);
-	return 0;
-}
-
-// get_float(self, name)
-int NodeMetaRef::l_get_float(lua_State *L)
-{
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	std::string name = lua_tostring(L, 2);
-
-	NodeMetadata *meta = ref->getmeta(false);
-	if(meta == NULL){
-		lua_pushnumber(L, 0);
-		return 1;
-	}
-	std::string str = meta->getString(name);
-	lua_pushnumber(L, stof(str));
-	return 1;
-}
-
-// set_float(self, name, var)
-int NodeMetaRef::l_set_float(lua_State *L)
-{
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	std::string name = lua_tostring(L, 2);
-	float a = lua_tonumber(L, 3);
-	std::string str = ftos(a);
-
-	NodeMetadata *meta = ref->getmeta(true);
-	if(meta == NULL || str == meta->getString(name))
-		return 0;
-	meta->setString(name, str);
-	reportMetadataChange(ref);
-	return 0;
-}
-
 // get_inventory(self)
 int NodeMetaRef::l_get_inventory(lua_State *L)
 {
@@ -195,34 +91,12 @@ int NodeMetaRef::l_get_inventory(lua_State *L)
 	return 1;
 }
 
-// to_table(self)
-int NodeMetaRef::l_to_table(lua_State *L)
+void NodeMetaRef::handleToTable(lua_State *L, Metadata *_meta)
 {
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-
-	NodeMetadata *meta = ref->getmeta(true);
-	if (meta == NULL) {
-		lua_pushnil(L);
-		return 1;
-	}
-	lua_newtable(L);
-
 	// fields
-	lua_newtable(L);
-	{
-		StringMap fields = meta->getStrings();
-		for (StringMap::const_iterator
-				it = fields.begin(); it != fields.end(); ++it) {
-			const std::string &name = it->first;
-			const std::string &value = it->second;
-			lua_pushlstring(L, name.c_str(), name.size());
-			lua_pushlstring(L, value.c_str(), value.size());
-			lua_settable(L, -3);
-		}
-	}
-	lua_setfield(L, -2, "fields");
+	MetaDataRef::handleToTable(L, _meta);
+
+	NodeMetadata *meta = (NodeMetadata*) _meta;
 
 	// inventory
 	lua_newtable(L);
@@ -236,52 +110,20 @@ int NodeMetaRef::l_to_table(lua_State *L)
 		}
 	}
 	lua_setfield(L, -2, "inventory");
-	return 1;
 }
 
 // from_table(self, table)
-int NodeMetaRef::l_from_table(lua_State *L)
+bool NodeMetaRef::handleFromTable(lua_State *L, int table, Metadata *_meta)
 {
-	MAP_LOCK_REQUIRED;
-
-	NodeMetaRef *ref = checkobject(L, 1);
-	int base = 2;
-
-	// clear old metadata first
-	ref->m_env->getMap().removeNodeMetadata(ref->m_p);
-
-	if (!lua_istable(L, base)) {
-		// No metadata
-		lua_pushboolean(L, true);
-		return 1;
-	}
+	// fields
+	if (!MetaDataRef::handleFromTable(L, table, _meta))
+		return false;
 
-	// Create new metadata
-	NodeMetadata *meta = ref->getmeta(true);
-	if (meta == NULL) {
-		lua_pushboolean(L, false);
-		return 1;
-	}
+	NodeMetadata *meta = (NodeMetadata*) _meta;
 
-	// Set fields
-	lua_getfield(L, base, "fields");
-	if (lua_istable(L, -1)) {
-		int fieldstable = lua_gettop(L);
-		lua_pushnil(L);
-		while (lua_next(L, fieldstable) != 0) {
-			// key at index -2 and value at index -1
-			std::string name = lua_tostring(L, -2);
-			size_t cl;
-			const char *cs = lua_tolstring(L, -1, &cl);
-			meta->setString(name, std::string(cs, cl));
-			lua_pop(L, 1); // Remove value, keep key for next iteration
-		}
-		lua_pop(L, 1);
-	}
-
-	// Set inventory
+	// inventory
 	Inventory *inv = meta->getInventory();
-	lua_getfield(L, base, "inventory");
+	lua_getfield(L, table, "inventory");
 	if (lua_istable(L, -1)) {
 		int inventorytable = lua_gettop(L);
 		lua_pushnil(L);
@@ -294,9 +136,7 @@ int NodeMetaRef::l_from_table(lua_State *L)
 		lua_pop(L, 1);
 	}
 
-	reportMetadataChange(ref);
-	lua_pushboolean(L, true);
-	return 1;
+	return true;
 }
 
 
@@ -332,6 +172,10 @@ void NodeMetaRef::Register(lua_State *L)
 	lua_pushvalue(L, methodtable);
 	lua_settable(L, metatable);  // hide metatable from Lua getmetatable()
 
+	lua_pushliteral(L, "metadata_class");
+	lua_pushlstring(L, className, strlen(className));
+	lua_settable(L, metatable);
+
 	lua_pushliteral(L, "__index");
 	lua_pushvalue(L, methodtable);
 	lua_settable(L, metatable);
@@ -351,14 +195,14 @@ void NodeMetaRef::Register(lua_State *L)
 
 const char NodeMetaRef::className[] = "NodeMetaRef";
 const luaL_reg NodeMetaRef::methods[] = {
-	luamethod(NodeMetaRef, get_string),
-	luamethod(NodeMetaRef, set_string),
-	luamethod(NodeMetaRef, get_int),
-	luamethod(NodeMetaRef, set_int),
-	luamethod(NodeMetaRef, get_float),
-	luamethod(NodeMetaRef, set_float),
+	luamethod(MetaDataRef, get_string),
+	luamethod(MetaDataRef, set_string),
+	luamethod(MetaDataRef, get_int),
+	luamethod(MetaDataRef, set_int),
+	luamethod(MetaDataRef, get_float),
+	luamethod(MetaDataRef, set_float),
+	luamethod(MetaDataRef, to_table),
+	luamethod(MetaDataRef, from_table),
 	luamethod(NodeMetaRef, get_inventory),
-	luamethod(NodeMetaRef, to_table),
-	luamethod(NodeMetaRef, from_table),
 	{0,0}
 };
diff --git a/src/script/lua_api/l_nodemeta.h b/src/script/lua_api/l_nodemeta.h
index 4ce338b18..d03f086c9 100644
--- a/src/script/lua_api/l_nodemeta.h
+++ b/src/script/lua_api/l_nodemeta.h
@@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define L_NODEMETA_H_
 
 #include "lua_api/l_base.h"
+#include "lua_api/l_metadata.h"
 #include "irrlichttypes_bloated.h"
 
 class ServerEnvironment;
@@ -29,7 +30,7 @@ class NodeMetadata;
 	NodeMetaRef
 */
 
-class NodeMetaRef : public ModApiBase {
+class NodeMetaRef : public MetaDataRef {
 private:
 	v3s16 m_p;
 	ServerEnvironment *m_env;
@@ -52,42 +53,22 @@ private:
 	 * @param auto_create when true, try to create metadata information for the node if it has none.
 	 * @return pointer to a @c NodeMetadata object or @c NULL in case of error.
 	 */
-	virtual NodeMetadata* getmeta(bool auto_create);
+	virtual Metadata* getmeta(bool auto_create);
+	virtual void clearMeta();
 
-	static void reportMetadataChange(NodeMetaRef *ref);
+	virtual void reportMetadataChange();
+
+	virtual void handleToTable(lua_State *L, Metadata *_meta);
+	virtual bool handleFromTable(lua_State *L, int table, Metadata *_meta);
 
 	// Exported functions
 
 	// garbage collector
 	static int gc_object(lua_State *L);
 
-	// get_string(self, name)
-	static int l_get_string(lua_State *L);
-
-	// set_string(self, name, var)
-	static int l_set_string(lua_State *L);
-
-	// get_int(self, name)
-	static int l_get_int(lua_State *L);
-
-	// set_int(self, name, var)
-	static int l_set_int(lua_State *L);
-
-	// get_float(self, name)
-	static int l_get_float(lua_State *L);
-
-	// set_float(self, name, var)
-	static int l_set_float(lua_State *L);
-
 	// get_inventory(self)
 	static int l_get_inventory(lua_State *L);
 
-	// to_table(self)
-	static int l_to_table(lua_State *L);
-
-	// from_table(self, table)
-	static int l_from_table(lua_State *L);
-
 public:
 	NodeMetaRef(v3s16 p, ServerEnvironment *env);