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degesch: Lua: allow arbitrary userdata properties

This commit is contained in:
Přemysl Eric Janouch 2016-01-04 22:59:59 +01:00
parent a227060383
commit e9b39a1ef7
1 changed files with 35 additions and 2 deletions
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37
degesch.c
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@ -8173,8 +8173,38 @@ lua_plugin_property_get (lua_State *L)
return 1;
}
return luaL_error (L, "%s: %s",
"no such method or property", property_name);
// Or we look for a property set by the user (__gc cannot be overriden)
if (lua_getuservalue (L, 1) != LUA_TTABLE)
lua_pushnil (L);
else
lua_getfield (L, -1, property_name);
return 1;
}
static int
lua_plugin_property_set (lua_State *L)
{
luaL_checktype (L, 1, LUA_TUSERDATA);
const char *property_name = luaL_checkstring (L, 2);
luaL_checkany (L, 3);
// We use the associated value to store user-defined properties
int type = lua_getuservalue (L, 1);
if (type == LUA_TNIL)
{
lua_pop (L, 1);
lua_newtable (L);
lua_pushvalue (L, -1);
lua_setuservalue (L, 1);
}
else if (type != LUA_TTABLE)
return luaL_error (L, "associated value is not a table");
// Beware that we do not check for conflicts here;
// if Lua code writes a conflicting field, it is effectively ignored
lua_pushvalue (L, 3);
lua_setfield (L, -2, property_name);
return 0;
}
static void
@ -8186,6 +8216,9 @@ lua_plugin_create_meta (lua_State *L, const char *name, luaL_Reg *fns)
// Emulate properties for convenience
lua_pushcfunction (L, lua_plugin_property_get);
lua_setfield (L, -2, "__index");
lua_pushcfunction (L, lua_plugin_property_set);
lua_setfield (L, -2, "__newindex");
lua_pop (L, 1);
}