libs/core/src/luci_cutil.c

   1 /**
   2  * LuCI Core - Utility library
   3  * Copyright (C) 2008 Steven Barth <steven@midlink.org>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *      http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include "lauxlib.h"
  19
  20 #define LUCI_MODNAME "luci.cutil"
  21 #define LUCI_MODDESC "LuCI Core Utility Library"
  22 #define LUCI_MODCOPY "2008 Steven Barth"
  23
  24
  25 /* Pythonic overloaded MOD operator */
  26 static int luci__string_mod(lua_State *L) {
  27         int i, n=1;
  28
  29         luaL_checkstring(L, 1);
  30         luaL_checkany(L, 2);
  31
  32         /* Discard further arguments */
  33         lua_settop(L, 2);
  34
  35         /* Get format and push it to the bottom of the stack */
  36         lua_getfield(L, 1, "format");
  37         lua_insert(L, 1);
  38
  39         /* If second argument is a table, unpack it */
  40         if (lua_istable(L, 3)) {
  41                 n = lua_objlen(L, 3);
  42                 if (n > 0) {
  43                         luaL_checkstack(L, n, "too many results to unpack");
  44                         for (i=1; i<=n; i++) {
  45                                 lua_rawgeti(L, 3, i);
  46                         }
  47                 } else {
  48                         n = 0;
  49                 }
  50                 lua_remove(L, 3);
  51         }
  52
  53         lua_call(L, n+1, 1);
  54         return 1;
  55 }
  56
  57 /* Instantiate a class */
  58 static int luci__instantiate(lua_State *L) {
  59         luaL_checktype(L, 1, LUA_TTABLE);
  60
  61         /* Create the object */
  62         lua_newtable(L);
  63
  64         /* Create the metatable */
  65         lua_createtable(L, 0, 1);
  66         lua_pushvalue(L, 1);
  67         lua_setfield(L, -2, "__index");
  68         lua_setmetatable(L, -2);
  69
  70         /* Move instance at the bottom of the stack */
  71         lua_replace(L, 1);
  72
  73         /* Invoke constructor if it exists */
  74         lua_getfield(L, 1, "__init__");
  75         if (lua_isfunction(L, -1)) {
  76                 /* Put instance at the bottom for the 2nd time */
  77                 lua_pushvalue(L, 1);
  78                 lua_insert(L, 1);
  79
  80                 /* Call constructor */
  81                 lua_insert(L, 2);
  82                 lua_call(L, lua_gettop(L)-2, 0);
  83         }
  84
  85         lua_settop(L, 1);
  86         return 1;
  87 }
  88
  89
  90 /* luci.cutil.class(baseclass) */
  91 static int luci_class(lua_State *L) {
  92         /* Create class */
  93         lua_newtable(L);
  94
  95         /* Create metatable and register parent class if any */
  96         if (lua_gettop(L) > 1 && lua_istable(L, 1)) {
  97                 lua_createtable(L, 0, 2);
  98                 lua_pushvalue(L, 1);
  99                 lua_setfield(L, -2, "__index");
 100         } else {
 101                 lua_createtable(L, 0, 1);
 102         }
 103
 104         /* Set instantiator */
 105         lua_pushcfunction(L, luci__instantiate);
 106         lua_setfield(L, -2, "__call");
 107
 108         lua_setmetatable(L, -2);
 109         return 1;
 110 }
 111
 112 /* luci.cutil.instanceof(object, class) */
 113 static int luci_instanceof(lua_State *L) {
 114         int stat = 0;
 115
 116         luaL_checkany(L, 1);
 117         luaL_checkany(L, 2);
 118
 119         if (lua_getmetatable(L, 1)) {
 120                 /* get parent class */
 121                 lua_getfield(L, -1, "__index");
 122                 while (lua_istable(L, -1)) {
 123                         /* parent class == class */
 124                         if (lua_equal(L, -1, 2)) {
 125                                 stat = 1;
 126                                 break;
 127                         }
 128
 129                         /* remove last metatable */
 130                         lua_remove(L, -2);
 131
 132                         /* get metatable of parent class */
 133                         if (lua_getmetatable(L, -1)) {
 134                                 /* remove last parent class */
 135                                 lua_remove(L, -2);
 136
 137                                 /* get next parent class */
 138                                 lua_getfield(L, -1, "__index");
 139                         } else {
 140                                 break;
 141                         }
 142                 }
 143         }
 144
 145         lua_pushboolean(L, stat);
 146         return 1;
 147 }
 148
 149
 150 /* luci.cutil.pcdata(obj) */
 151 static int luci_pcdata(lua_State *L) {
 152         if (lua_isnone(L, 1)) {
 153                 lua_pushnil(L);
 154                 return 1;
 155         }
 156         luaL_checkstring(L, 1);
 157
 158         /* Discard anything else */
 159         lua_settop(L, 1);
 160
 161         /* pattern */
 162         lua_pushvalue(L, lua_upvalueindex(1));
 163
 164         /* repl */
 165         lua_pushvalue(L, lua_upvalueindex(2));
 166
 167         /* get gsub function */
 168         lua_getfield(L, 1, "gsub");
 169         lua_insert(L, 1);
 170
 171         /* tostring(obj):gsub(pattern, repl) */
 172         lua_call(L, 3, 1);
 173         return 1;
 174 }
 175
 176 /* luci.cutil.trim(str) */
 177 static int luci_trim(lua_State *L) {
 178         luaL_checkstring(L, 1);
 179         lua_settop(L, 1);
 180
 181         /* pattern and repl */
 182         lua_pushliteral(L, "^%s*(.-)%s*$");
 183         lua_pushliteral(L, "%1");
 184
 185         /* get str.gsub */
 186         lua_getfield(L, 1, "gsub");
 187         lua_insert(L, 1);
 188
 189         /* str.gsub(str, pattern, repl) */
 190         lua_call(L, 3, 1);
 191         return 1;
 192 }
 193
 194
 195 /* Registration helper for luci.cutil.pcdata */
 196 static void luci__register_pcdata(lua_State *L) {
 197         /* pattern */
 198         lua_pushliteral(L, "[&\"'<>]");
 199
 200         /* repl */
 201         lua_createtable(L, 0, 5);
 202
 203         lua_pushliteral(L, "&#38;");
 204         lua_setfield(L, -2, "&");
 205         lua_pushliteral(L, "&#34;");
 206         lua_setfield(L, -2, "\"");
 207         lua_pushliteral(L, "&#39;");
 208         lua_setfield(L, -2, "'");
 209         lua_pushliteral(L, "&#60;");
 210         lua_setfield(L, -2, "<");
 211         lua_pushliteral(L, "&#62;");
 212         lua_setfield(L, -2, ">");
 213
 214         /* register function */
 215         lua_pushcclosure(L, luci_pcdata, 2);
 216         lua_setfield(L, -2, "pcdata");
 217 }
 218
 219 /* Registry */
 220 static const luaL_Reg registry[] = {
 221                 {"class",               luci_class},
 222                 {"instanceof",  luci_instanceof},
 223                 {"trim",                luci_trim},
 224                 { NULL,                 NULL },
 225 };
 226
 227 /* Registrator */
 228 LUALIB_API int luaopen_luci_cutil(lua_State *L) {
 229         luaL_register(L, LUCI_MODNAME, registry);
 230
 231         lua_pushliteral(L, LUCI_MODDESC);
 232         lua_setfield(L, -2, "_DESCRIPTION");
 233
 234         lua_pushliteral(L, LUCI_MODCOPY);
 235         lua_setfield(L, -2, "_COPYRIGHT");
 236
 237         /* Additional registrations */
 238         luci__register_pcdata(L);
 239
 240
 241         /* Register pythonic printf string operator */
 242         lua_pushliteral(L, "");
 243         lua_getmetatable(L, -1);
 244         lua_pushcfunction(L, luci__string_mod);
 245         lua_setfield(L, -2, "__mod");
 246         lua_pop(L, 2);
 247
 248         return 1;
 249 }