libs/uvl/luasrc/uvl.lua

   1 --[[
   2
   3 UCI Validation Layer - Main Library
   4 (c) 2008 Jo-Philipp Wich <xm@leipzig.freifunk.net>
   5 (c) 2008 Steven Barth <steven@midlink.org>
   6
   7 Licensed under the Apache License, Version 2.0 (the "License");
   8 you may not use this file except in compliance with the License.
   9 You may obtain a copy of the License at
  10
  11         http://www.apache.org/licenses/LICENSE-2.0
  12
  13 $Id$
  14
  15 ]]--
  16
  17
  18 --- UVL - UCI Validation Layer
  19 -- @class       module
  20 -- @cstyle      instance
  21
  22 module( "luci.uvl", package.seeall )
  23
  24 require("luci.fs")
  25 require("luci.util")
  26 require("luci.model.uci")
  27 require("luci.uvl.errors")
  28 require("luci.uvl.datatypes")
  29 require("luci.uvl.validation")
  30 require("luci.uvl.dependencies")
  31
  32
  33 TYPE_SCHEME   = 0x00
  34 TYPE_CONFIG   = 0x01
  35 TYPE_SECTION  = 0x02
  36 TYPE_VARIABLE = 0x03
  37 TYPE_OPTION   = 0x04
  38 TYPE_ENUM     = 0x05
  39
  40 --- Boolean; default true;
  41 -- treat sections found in config but not in scheme as error
  42 STRICT_UNKNOWN_SECTIONS    = true
  43
  44 --- Boolean; default true;
  45 -- treat options found in config but not in scheme as error
  46 STRICT_UNKNOWN_OPTIONS     = true
  47
  48 --- Boolean; default true;
  49 -- treat failed external validators as error
  50 STRICT_EXTERNAL_VALIDATORS = true
  51
  52 --- Boolean; default true;
  53 -- treat list values stored as options like errors
  54 STRICT_LIST_TYPE           = true
  55
  56
  57 local default_schemedir = "/lib/uci/schema"
  58 local default_savedir = "/tmp/.uvl"
  59 local ERR = luci.uvl.errors
  60
  61
  62 --- Object constructor
  63 -- @class                       function
  64 -- @name                        UVL
  65 -- @param schemedir     Path to the scheme directory (optional)
  66 -- @return                      Instance object
  67 UVL = luci.util.class()
  68
  69 function UVL.__init__( self, schemedir )
  70         self.schemedir  = schemedir or default_schemedir
  71         self.packages   = { }
  72         self.beenthere  = { }
  73         self.depseen    = { }
  74         self.uci                = luci.model.uci
  75         self.err                = luci.uvl.errors
  76         self.dep                = luci.uvl.dependencies
  77         self.datatypes  = luci.uvl.datatypes
  78 end
  79
  80
  81 --- Parse given scheme and return the scheme tree.
  82 -- @param scheme        Name of the scheme to parse
  83 -- @return                      Table containing the parsed scheme or nil on error
  84 -- @return                      String containing the reason for errors (if any)
  85 function UVL.get_scheme( self, scheme )
  86         if not self.packages[scheme] then
  87                 local ok, err = self:read_scheme( scheme )
  88                 if not ok then
  89                         return nil, err
  90                 end
  91         end
  92         return self.packages[scheme], nil
  93 end
  94
  95 --- Validate given configuration, section or option.
  96 -- @param config        Name of the configuration to validate
  97 -- @param section       Name of the section to validate (optional)
  98 -- @param option        Name of the option to validate (optional)
  99 -- @return                      Boolean indicating whether the given config validates
 100 -- @return                      String containing the reason for errors (if any)
 101 function UVL.validate( self, config, section, option )
 102         if config and section and option then
 103                 return self:validate_option( config, section, option )
 104         elseif config and section then
 105                 return self:validate_section( config, section )
 106         elseif config then
 107                 return self:validate_config( config )
 108         end
 109 end
 110
 111 --- Validate given configuration.
 112 -- @param config        Name of the configuration to validate
 113 -- @return                      Boolean indicating whether the given config validates
 114 -- @return                      String containing the reason for errors (if any)
 115 function UVL.validate_config( self, config, uci )
 116
 117         if not self.packages[config] then
 118                 local ok, err = self:read_scheme(config)
 119                 if not ok then
 120                         return false, err
 121                 end
 122         end
 123
 124         local co = luci.uvl.config( self, uci or config, uci and config )
 125         local sc = { }
 126
 127         self.beenthere = { }
 128         self.depseen   = { }
 129
 130         if not co:config() then
 131                 return false, co:errors()
 132         end
 133
 134         local function _uci_foreach( type, func )
 135                 for k, v in pairs(co:config()) do
 136                         if v['.type'] == type then
 137                                 sc[type] = sc[type] + 1
 138                                 local ok, err = func( k, v )
 139                                 if not ok then co:error(err) end
 140                         end
 141                 end
 142         end
 143
 144         for k, v in pairs( self.packages[config].sections ) do
 145                 sc[k] = 0
 146                 _uci_foreach( k,
 147                         function(s)
 148                                 return self:_validate_section( co:section(s) )
 149                         end
 150                 )
 151         end
 152
 153         if STRICT_UNKNOWN_SECTIONS then
 154                 for k, v in pairs(co:config()) do
 155                         local so = co:section(k)
 156                         if not self.beenthere[so:cid()] then
 157                                 co:error(ERR.SECT_UNKNOWN(so))
 158                         end
 159                 end
 160         end
 161
 162         for _, k in ipairs(luci.util.keys(sc)) do
 163                 local so = co:section(k)
 164                 if so:scheme('required') and sc[k] == 0 then
 165                         co:error(ERR.SECT_REQUIRED(so))
 166                 elseif so:scheme('unique') and sc[k] > 1 then
 167                         co:error(ERR.SECT_UNIQUE(so))
 168                 end
 169         end
 170
 171         return co:ok(), co:errors()
 172 end
 173
 174 --- Validate given config section.
 175 -- @param config        Name of the configuration to validate
 176 -- @param section       Name of the section to validate
 177 -- @return                      Boolean indicating whether the given config validates
 178 -- @return                      String containing the reason for errors (if any)
 179 function UVL.validate_section( self, config, section, uci )
 180
 181         if not self.packages[config] then
 182                 local ok, err = self:read_scheme( config )
 183                 if not ok then
 184                         return false, err
 185                 end
 186         end
 187
 188         local co = luci.uvl.config( self, uci or config, uci and config )
 189         local so = co:section( section )
 190
 191         self.beenthere = { }
 192         self.depseen   = { }
 193
 194         if not co:config() then
 195                 return false, co:errors()
 196         end
 197
 198         if so:config() then
 199                 return self:_validate_section( so )
 200         else
 201                 return false, ERR.SECT_NOTFOUND(so)
 202         end
 203 end
 204
 205 --- Validate given config option.
 206 -- @param config        Name of the configuration to validate
 207 -- @param section       Name of the section to validate
 208 -- @param option        Name of the option to validate
 209 -- @return                      Boolean indicating whether the given config validates
 210 -- @return                      String containing the reason for errors (if any)
 211 function UVL.validate_option( self, config, section, option, uci )
 212
 213         if not self.packages[config] then
 214                 local ok, err = self:read_scheme( config )
 215                 if not ok then
 216                         return false, err
 217                 end
 218         end
 219
 220         local co = luci.uvl.config( self, uci or config, uci and config )
 221         local so = co:section( section )
 222         local oo = so:option( option )
 223
 224         if not co:config() then
 225                 return false, co:errors()
 226         end
 227
 228         if so:config() and oo:config() then
 229                 return self:_validate_option( oo )
 230         else
 231                 return false, ERR.OPT_NOTFOUND(oo)
 232         end
 233 end
 234
 235
 236 function UVL._validate_section( self, section )
 237
 238         self.beenthere[section:cid()] = true
 239
 240         if section:config() then
 241                 if section:scheme('named') == true and
 242                    section:config('.anonymous') == true
 243                 then
 244                         return false, ERR.SECT_NAMED(section)
 245                 end
 246
 247                 for _, v in ipairs(section:variables()) do
 248                         local ok, err = self:_validate_option( v )
 249                         if not ok then
 250                                 section:error(err)
 251                         end
 252                 end
 253
 254                 local ok, err = luci.uvl.dependencies.check( self, section )
 255                 if not ok then
 256                         section:error(err)
 257                 end
 258         else
 259                 return false, ERR.SECT_NOTFOUND(section)
 260         end
 261
 262         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 263                 for k, v in pairs(section:config()) do
 264                         local oo = section:option(k)
 265                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 266                                 section:error(ERR.OPT_NOTFOUND(oo))
 267                         end
 268                 end
 269         end
 270
 271         return section:ok(), section:errors()
 272 end
 273
 274 function UVL._validate_option( self, option, nodeps )
 275
 276         self.beenthere[option:cid()] = true
 277
 278         if not option:scheme() and not option:parent():scheme('dynamic') then
 279                 return false, option:error(ERR.OPT_UNKNOWN(option))
 280
 281         elseif option:scheme() then
 282                 if option:scheme('required') and not option:value() then
 283                         return false, option:error(ERR.OPT_REQUIRED(option))
 284
 285                 elseif option:value() then
 286                         local val = option:value()
 287
 288                         if option:scheme('type') == "reference" or
 289                            option:scheme('type') == "enum"
 290                         then
 291                                 if not option:scheme('values') or
 292                                    not option:scheme('values')[val]
 293                                 then
 294                                         return false, option:error( ERR.OPT_BADVALUE(
 295                                                 option, { val, table.concat(
 296                                                         luci.util.keys(option:scheme('values') or {}), ", "
 297                                                 ) }
 298                                         ) )
 299                                 end
 300                         elseif option:scheme('type') == "list" then
 301                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 302                                         return false, option:error(ERR.OPT_NOTLIST(option))
 303                                 end
 304                         elseif option:scheme('datatype') then
 305                                 local dt = option:scheme('datatype')
 306
 307                                 if self.datatypes[dt] then
 308                                         val = ( type(val) == "table" and val or { val } )
 309                                         for i, v in ipairs(val) do
 310                                                 if not self.datatypes[dt]( v ) then
 311                                                         return false, option:error(
 312                                                                 ERR.OPT_INVVALUE(option, {v, dt})
 313                                                         )
 314                                                 end
 315                                         end
 316                                 else
 317                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 318                                 end
 319                         end
 320                 end
 321
 322                 if not nodeps then
 323                         local ok, err = luci.uvl.dependencies.check( self, option )
 324                         if not ok then
 325                                 option:error(err)
 326                         end
 327                 end
 328
 329                 local ok, err = luci.uvl.validation.check( self, option )
 330                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 331                         return false, option:error(err)
 332                 end
 333         end
 334
 335         return option:ok(), option:errors()
 336 end
 337
 338 --- Find all parts of given scheme and construct validation tree.
 339 -- This is normally done on demand, so you don't have to call this function
 340 -- by yourself.
 341 -- @param scheme        Name of the scheme to parse
 342 function UVL.read_scheme( self, scheme )
 343
 344         local so = luci.uvl.scheme( self, scheme )
 345
 346         local schemes = { }
 347         local files = luci.fs.glob(self.schemedir .. '/*/' .. scheme)
 348
 349         if files then
 350                 for i, file in ipairs( files ) do
 351                         if not luci.fs.access(file) then
 352                                 return so:error(ERR.SME_READ(so,file))
 353                         end
 354
 355                         local uci = luci.model.uci.cursor( luci.fs.dirname(file), default_savedir )
 356
 357                         local sd, err = uci:get_all( luci.fs.basename(file) )
 358
 359                         if not sd then
 360                                 return false, ERR.UCILOAD(so, err)
 361                         end
 362
 363                         table.insert( schemes, sd )
 364                 end
 365
 366                 return self:_read_scheme_parts( so, schemes )
 367         else
 368                 return false, so:error(ERR.SME_FIND(so, self.schemedir))
 369         end
 370 end
 371
 372 -- Process all given parts and construct validation tree
 373 function UVL._read_scheme_parts( self, scheme, schemes )
 374
 375         -- helper function to check for required fields
 376         local function _req( c, t, r )
 377                 for i, v in ipairs(r) do
 378                         if not t[v] then
 379                                 return false, ERR.SME_REQFLD({c,t}, v)
 380                         end
 381                 end
 382                 return true
 383         end
 384
 385         -- helper function to validate references
 386         local function _ref( c, t )
 387                 local k, n
 388                 if c == TYPE_SECTION then
 389                         k = "package"
 390                         n = 1
 391                 elseif c == TYPE_VARIABLE then
 392                         k = "section"
 393                         n = 2
 394                 elseif c == TYPE_ENUM then
 395                         k = "variable"
 396                         n = 3
 397                 end
 398
 399                 local r = luci.util.split( t[k], "." )
 400                 r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 401
 402                 if #r ~= n then
 403                         return false, ERR.SME_BADREF(scheme, k)
 404                 end
 405
 406                 return r
 407         end
 408
 409         -- helper function to read bools
 410         local function _bool( v )
 411                 return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 412         end
 413
 414
 415         local ok, err
 416
 417         -- Step 1: get all sections
 418         for i, conf in ipairs( schemes ) do
 419                 for k, v in pairs( conf ) do
 420                         if v['.type'] == 'section' then
 421
 422                                 ok, err = _req( TYPE_SECTION, v, { "name", "package" } )
 423                                 if err then return false, scheme:error(err) end
 424
 425                                 local r, err = _ref( TYPE_SECTION, v )
 426                                 if err then return false, scheme:error(err) end
 427
 428                                 self.packages[r[1]] =
 429                                         self.packages[r[1]] or {
 430                                                 ["name"]      = r[1];
 431                                                 ["sections"]  = { };
 432                                                 ["variables"] = { };
 433                                         }
 434
 435                                 local p = self.packages[r[1]]
 436                                           p.sections[v.name]  = p.sections[v.name]  or { }
 437                                           p.variables[v.name] = p.variables[v.name] or { }
 438
 439                                 local s  = p.sections[v.name]
 440                                 local so = scheme:section(v.name)
 441
 442                                 for k, v2 in pairs(v) do
 443                                         if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 444                                                 if k == "depends" then
 445                                                         s.depends = self:_read_dependency( v2, s.depends )
 446                                                         if not s.depends then
 447                                                                 return false, scheme:error(
 448                                                                         ERR.SME_BADDEP(so, luci.util.serialize_data(s.depends))
 449                                                                 )
 450                                                         end
 451                                                 elseif k == "dynamic" or k == "unique" or
 452                                                        k == "required" or k == "named"
 453                                                 then
 454                                                         s[k] = _bool(v2)
 455                                                 else
 456                                                         s[k] = v2
 457                                                 end
 458                                         end
 459                                 end
 460
 461                                 s.dynamic  = s.dynamic  or false
 462                                 s.unique   = s.unique   or false
 463                                 s.required = s.required or false
 464                                 s.named    = s.named    or false
 465                         end
 466                 end
 467         end
 468
 469         -- Step 2: get all variables
 470         for i, conf in ipairs( schemes ) do
 471                 for k, v in pairs( conf ) do
 472                         if v['.type'] == "variable" then
 473
 474                                 ok, err = _req( TYPE_VARIABLE, v, { "name", "section" } )
 475                                 if err then return false, scheme:error(err) end
 476
 477                                 local r, err = _ref( TYPE_VARIABLE, v )
 478                                 if err then return false, scheme:error(err) end
 479
 480                                 local p = self.packages[r[1]]
 481                                 if not p then
 482                                         return false, scheme:error(
 483                                                 ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 484                                         )
 485                                 end
 486
 487                                 local s = p.variables[r[2]]
 488                                 if not s then
 489                                         return false, scheme:error(
 490                                                 ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 491                                         )
 492                                 end
 493
 494                                 s[v.name] = s[v.name] or { }
 495
 496                                 local t  = s[v.name]
 497                                 local so = scheme:section(r[2])
 498                                 local to = so:option(v.name)
 499
 500                                 for k, v2 in pairs(v) do
 501                                         if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 502                                                 if k == "depends" then
 503                                                         t.depends = self:_read_dependency( v2, t.depends )
 504                                                         if not t.depends then
 505                                                                 return false, scheme:error(so:error(
 506                                                                         ERR.SME_BADDEP(to, luci.util.serialize_data(v2))
 507                                                                 ))
 508                                                         end
 509                                                 elseif k == "validator" then
 510                                                         t.validators = self:_read_validator( v2, t.validators )
 511                                                         if not t.validators then
 512                                                                 return false, scheme:error(so:error(
 513                                                                         ERR.SME_BADVAL(to, luci.util.serialize_data(v2))
 514                                                                 ))
 515                                                         end
 516                                                 elseif k == "valueof" then
 517                                                         local values, err = self:_read_reference( v2 )
 518                                                         if err then
 519                                                                 return false, scheme:error(so:error(
 520                                                                         ERR.REFERENCE(to, luci.util.serialize_data(v2)):child(err)
 521                                                                 ))
 522                                                         end
 523                                                         t.type   = "reference"
 524                                                         t.values = values
 525                                                 elseif k == "required" then
 526                                                         t[k] = _bool(v2)
 527                                                 else
 528                                                         t[k] = t[k] or v2
 529                                                 end
 530                                         end
 531                                 end
 532
 533                                 t.type     = t.type     or "variable"
 534                                 t.datatype = t.datatype or "string"
 535                                 t.required = t.required or false
 536                         end
 537                 end
 538         end
 539
 540         -- Step 3: get all enums
 541         for i, conf in ipairs( schemes ) do
 542                 for k, v in pairs( conf ) do
 543                         if v['.type'] == "enum" then
 544
 545                                 ok, err = _req( TYPE_ENUM, v, { "value", "variable" } )
 546                                 if err then return false, scheme:error(err) end
 547
 548                                 local r, err = _ref( TYPE_ENUM, v )
 549                                 if err then return false, scheme:error(err) end
 550
 551                                 local p = self.packages[r[1]]
 552                                 if not p then
 553                                         return false, scheme:error(
 554                                                 ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 555                                         )
 556                                 end
 557
 558                                 local s = p.variables[r[2]]
 559                                 if not s then
 560                                         return false, scheme:error(
 561                                                 ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 562                                         )
 563                                 end
 564
 565                                 local t = s[r[3]]
 566                                 if not t then
 567                                         return false, scheme:error(
 568                                                 ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 569                                         )
 570                                 end
 571
 572
 573                                 local so = scheme:section(r[2])
 574                                 local oo = so:option(r[3])
 575                                 local eo = oo:enum(v.value)
 576
 577                                 if t.type ~= "enum" then
 578                                         return false, scheme:error(ERR.SME_EBADTYPE(eo))
 579                                 end
 580
 581                                 if not t.values then
 582                                         t.values = { [v.value] = v.title or v.value }
 583                                 else
 584                                         t.values[v.value] = v.title or v.value
 585                                 end
 586
 587                                 if not t.enum_depends then
 588                                         t.enum_depends = { }
 589                                 end
 590
 591                                 if v.default then
 592                                         if t.default then
 593                                                 return false, scheme:error(ERR.SME_EBADDEF(eo))
 594                                         end
 595                                         t.default = v.value
 596                                 end
 597
 598                                 if v.depends then
 599                                         t.enum_depends[v.value] = self:_read_dependency(
 600                                                 v.depends, t.enum_depends[v.value]
 601                                         )
 602
 603                                         if not t.enum_depends[v.value] then
 604                                                 return false, scheme:error(so:error(oo:error(
 605                                                         ERR.SME_BADDEP(eo, luci.util.serialize_data(v.depends))
 606                                                 )))
 607                                         end
 608                                 end
 609                         end
 610                 end
 611         end
 612
 613         return self
 614 end
 615
 616 -- Read a dependency specification
 617 function UVL._read_dependency( self, values, deps )
 618         local expr = "%$?[a-zA-Z0-9_]+"
 619         if values then
 620                 values = ( type(values) == "table" and values or { values } )
 621                 for _, value in ipairs(values) do
 622                         local parts     = luci.util.split( value, "%s*,%s*", nil, true )
 623                         local condition = { }
 624                         for i, val in ipairs(parts) do
 625                                 local k, v = unpack(luci.util.split(val, "%s*=%s*", nil, true))
 626
 627                                 if k and (
 628                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 629                                         k:match("^"..expr.."%."..expr.."$") or
 630                                         k:match("^"..expr.."$")
 631                                 ) then
 632                                         condition[k] = v or true
 633                                 else
 634                                         return nil
 635                                 end
 636                         end
 637
 638                         if not deps then
 639                                 deps = { condition }
 640                         else
 641                                 table.insert( deps, condition )
 642                         end
 643                 end
 644         end
 645
 646         return deps
 647 end
 648
 649 -- Read a validator specification
 650 function UVL._read_validator( self, values, validators )
 651         if values then
 652                 values = ( type(values) == "table" and values or { values } )
 653                 for _, value in ipairs(values) do
 654                         local validator
 655
 656                         if value:match("^exec:") then
 657                                 validator = value:gsub("^exec:","")
 658                         elseif value:match("^lua:") then
 659                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 660                         end
 661
 662                         if validator then
 663                                 if not validators then
 664                                         validators = { validator }
 665                                 else
 666                                         table.insert( validators, validator )
 667                                 end
 668                         else
 669                                 return nil
 670                         end
 671                 end
 672
 673                 return validators
 674         end
 675 end
 676
 677 -- Read a reference specification (XXX: We should validate external configs too...)
 678 function UVL._read_reference( self, values )
 679         local val = { }
 680         values = ( type(values) == "table" and values or { values } )
 681
 682         for _, value in ipairs(values) do
 683                 local ref = luci.util.split(value, ".")
 684
 685                 if #ref == 2 or #ref == 3 then
 686                         local co = luci.uvl.config( self, ref[1] )
 687                         if not co:config() then return false, co:errors() end
 688
 689                         for k, v in pairs(co:config()) do
 690                                 if v['.type'] == ref[2] then
 691                                         if #ref == 2 then
 692                                                 if v['.anonymous'] == true then
 693                                                         return false, ERR.SME_INVREF('', value)
 694                                                 end
 695                                                 val[k] = k      -- XXX: title/description would be nice
 696                                         elseif v[ref[3]] then
 697                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 698                                         end
 699                                 end
 700                         end
 701                 else
 702                         return false, ERR.SME_BADREF('', value)
 703                 end
 704         end
 705
 706         return val, nil
 707 end
 708
 709 -- Resolve given path
 710 function UVL._resolve_function( self, value )
 711         local path = luci.util.split(value, ".")
 712
 713         for i=1, #path-1 do
 714                 local stat, mod = luci.util.copcall(
 715                         require, table.concat(path, ".", 1, i)
 716                 )
 717
 718                 if stat and mod then
 719                         for j=i+1, #path-1 do
 720                                 if not type(mod) == "table" then
 721                                         break
 722                                 end
 723                                 mod = mod[path[j]]
 724                                 if not mod then
 725                                         break
 726                                 end
 727                         end
 728                         mod = type(mod) == "table" and mod[path[#path]] or nil
 729                         if type(mod) == "function" then
 730                                 return mod
 731                         end
 732                 end
 733         end
 734 end
 735
 736
 737 --- Object representation of an uvl item - base class.
 738 uvlitem = luci.util.class()
 739
 740 function uvlitem.cid(self)
 741         return table.concat( self.cref, '.' )
 742 end
 743
 744 function uvlitem.sid(self)
 745         return table.concat( self.sref, '.' )
 746 end
 747
 748 function uvlitem.scheme(self, opt)
 749         local s
 750
 751         if #self.sref == 4 or #self.sref == 3 then
 752                 s = self.s
 753                         .packages[self.sref[1]]
 754                         .variables[self.sref[2]][self.sref[3]]
 755         elseif #self.sref == 2 then
 756                 s = self.s
 757                         .packages[self.sref[1]]
 758                         .sections[self.sref[2]]
 759         else
 760                 s = self.s
 761                         .packages[self.sref[1]]
 762         end
 763
 764         if s and opt then
 765                 return s[opt]
 766         elseif s then
 767                 return s
 768         end
 769 end
 770
 771 function uvlitem.config(self, opt)
 772         local c
 773
 774         if #self.cref == 4 or #self.cref == 3 then
 775                 c = self.c[self.cref[2]][self.cref[3]]
 776         elseif #self.cref == 2 then
 777                 c = self.c[self.cref[2]]
 778         else
 779                 c = self.c
 780         end
 781
 782         if c and opt then
 783                 return c[opt]
 784         elseif c then
 785                 return c
 786         end
 787 end
 788
 789 function uvlitem.title(self)
 790         return self:scheme() and self:scheme('title') or
 791                 self.cref[3] or self.cref[2] or self.cref[1]
 792 end
 793
 794 function uvlitem.type(self)
 795         if self.t == luci.uvl.TYPE_CONFIG then
 796                 return 'config'
 797         elseif self.t == luci.uvl.TYPE_SECTION then
 798                 return 'section'
 799         elseif self.t == luci.uvl.TYPE_OPTION then
 800                 return 'option'
 801         elseif self.t == luci.uvl.TYPE_ENUM then
 802                 return 'enum'
 803         end
 804 end
 805
 806 function uvlitem.error(self, ...)
 807         if not self.e then
 808                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 809                 self.e = errconst[#self.cref]( self )
 810         end
 811
 812         return self.e:child( ... )
 813 end
 814
 815 function uvlitem.errors(self)
 816         return self.e
 817 end
 818
 819 function uvlitem.ok(self)
 820         return not self:errors()
 821 end
 822
 823 function uvlitem.parent(self)
 824         if self.p then
 825                 return self.p
 826         elseif #self.cref == 3 or #self.cref == 4 then
 827                 return luci.uvl.section( self.s, self.c, self.cref[1], self.cref[2] )
 828         elseif #self.cref == 2 then
 829                 return luci.uvl.config( self.s, self.c, self.cref[1] )
 830         else
 831                 return nil
 832         end
 833 end
 834
 835 function uvlitem._loadconf(self, co, c)
 836         if not co then
 837                 local uci, err = luci.model.uci.cursor(), nil
 838                 co, err = uci:get_all(c)
 839
 840                 if err then
 841                         self:error(ERR.UCILOAD(self, err))
 842                 end
 843         end
 844         return co
 845 end
 846
 847
 848 --- Object representation of a scheme.
 849 -- @class       scheme
 850 -- @cstyle      instance
 851 -- @name        luci.uvl.scheme
 852
 853 --- Scheme instance constructor.
 854 -- @class                       function
 855 -- @name                        scheme
 856 -- @param scheme        Scheme instance
 857 -- @param co            Configuration data
 858 -- @param c                     Configuration name
 859 -- @return                      Config instance
 860 scheme = luci.util.class(uvlitem)
 861
 862 function scheme.__init__(self, scheme, co, c)
 863         if not c then
 864                 c, co = co, nil
 865         end
 866
 867         self.cref = { c }
 868         self.sref = { c }
 869         self.c    = self:_loadconf(co, c)
 870         self.s    = scheme
 871         self.t    = luci.uvl.TYPE_SCHEME
 872 end
 873
 874 --- Add an error to scheme.
 875 -- @return      Scheme error context
 876 function scheme.error(self, ...)
 877         if not self.e then self.e = ERR.SCHEME( self ) end
 878         return self.e:child( ... )
 879 end
 880
 881 --- Get an associated config object.
 882 -- @return      Config instance
 883 function scheme.config(self)
 884         local co = luci.uvl.config( self.s, self.cref[1] )
 885               co.p = self
 886
 887         return co
 888 end
 889
 890 --- Get all section objects associated with this scheme.
 891 -- @return      Table containing all associated luci.uvl.section instances
 892 function scheme.sections(self)
 893         local v = { }
 894         if self.s.packages[self.sref[1]].sections then
 895                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 896                         table.insert( v, luci.uvl.option(
 897                                 self.s, self.c, self.cref[1], self.cref[2], o
 898                         ) )
 899                 end
 900         end
 901         return v
 902 end
 903
 904 --- Get an associated section object.
 905 -- @param s     Section to select
 906 -- @return      Section instance
 907 function scheme.section(self, s)
 908         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 909               so.p = self
 910
 911         return so
 912 end
 913
 914
 915 --- Object representation of a config.
 916 -- @class       config
 917 -- @cstyle      instance
 918 -- @name        luci.uvl.config
 919
 920 --- Config instance constructor.
 921 -- @class                       function
 922 -- @name                        config
 923 -- @param scheme        Scheme instance
 924 -- @param co            Configuration data
 925 -- @param c                     Configuration name
 926 -- @return                      Config instance
 927 config = luci.util.class(uvlitem)
 928
 929 function config.__init__(self, scheme, co, c)
 930         if not c then
 931                 c, co = co, nil
 932         end
 933
 934         self.cref = { c }
 935         self.sref = { c }
 936         self.c    = self:_loadconf(co, c)
 937         self.s    = scheme
 938         self.t    = luci.uvl.TYPE_CONFIG
 939 end
 940
 941 --- Get all section objects associated with this config.
 942 -- @return      Table containing all associated luci.uvl.section instances
 943 function config.sections(self)
 944         local v = { }
 945         if self.s.packages[self.sref[1]].sections then
 946                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 947                         table.insert( v, luci.uvl.option(
 948                                 self.s, self.c, self.cref[1], self.cref[2], o
 949                         ) )
 950                 end
 951         end
 952         return v
 953 end
 954
 955 --- Get an associated section object.
 956 -- @param s     Section to select
 957 -- @return      Section instance
 958 function config.section(self, s)
 959         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 960               so.p = self
 961
 962         return so
 963 end
 964
 965
 966 --- Object representation of a scheme/config section.
 967 -- @class       module
 968 -- @cstyle      instance
 969 -- @name        luci.uvl.section
 970
 971 --- Section instance constructor.
 972 -- @class                       function
 973 -- @name                        section
 974 -- @param scheme        Scheme instance
 975 -- @param co            Configuration data
 976 -- @param c                     Configuration name
 977 -- @param s                     Section name
 978 -- @return                      Section instance
 979 section = luci.util.class(uvlitem)
 980
 981 function section.__init__(self, scheme, co, c, s)
 982         self.cref = { c, s }
 983         self.sref = { c, co and co[s] and co[s]['.type'] or s }
 984         self.c    = self:_loadconf(co, c)
 985         self.s    = scheme
 986         self.t    = luci.uvl.TYPE_SECTION
 987 end
 988
 989 --- Get all option objects associated with this section.
 990 -- @return      Table containing all associated luci.uvl.option instances
 991 function section.variables(self)
 992         local v = { }
 993         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
 994                 for o, _ in pairs(
 995                         self.s.packages[self.sref[1]].variables[self.sref[2]]
 996                 ) do
 997                         table.insert( v, luci.uvl.option(
 998                                 self.s, self.c, self.cref[1], self.cref[2], o
 999                         ) )
1000                 end
1001         end
1002         return v
1003 end
1004
1005 --- Get an associated option object.
1006 -- @param o     Option to select
1007 -- @return      Option instance
1008 function section.option(self, o)
1009         local oo = luci.uvl.option( self.s, self.c, self.cref[1], self.cref[2], o )
1010               oo.p = self
1011
1012         return oo
1013 end
1014
1015
1016 --- Object representation of a scheme/config option.
1017 -- @class       module
1018 -- @cstyle      instance
1019 -- @name        luci.uvl.option
1020
1021 --- Section instance constructor.
1022 -- @class                       function
1023 -- @name                        option
1024 -- @param scheme        Scheme instance
1025 -- @param co            Configuration data
1026 -- @param c                     Configuration name
1027 -- @param s                     Section name
1028 -- @param o                     Option name
1029 -- @return                      Option instance
1030 option = luci.util.class(uvlitem)
1031
1032 function option.__init__(self, scheme, co, c, s, o)
1033         self.cref = { c, s, o }
1034         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1035         self.c    = self:_loadconf(co, c)
1036         self.s    = scheme
1037         self.t    = luci.uvl.TYPE_OPTION
1038 end
1039
1040 --- Get the value of this option.
1041 -- @return      The associated configuration value
1042 function option.value(self)
1043         return self:config()
1044 end
1045
1046 --- Get the associated section information in scheme.
1047 -- @return      Table containing the scheme properties
1048 function option.section(self)
1049         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1050 end
1051
1052 --- Construct an enum object instance from given or default value.
1053 -- @param v     Value to select
1054 -- @return      Enum instance for selected value
1055 function option.enum(self, val)
1056         return enum(
1057                 self.s, self.c,
1058                 self.cref[1], self.cref[2], self.cref[3],
1059                 val or self:value()
1060         )
1061 end
1062
1063
1064 --- Object representation of a enum value.
1065 -- @class       module
1066 -- @cstyle      instance
1067 -- @name        luci.uvl.enum
1068
1069 --- Section instance constructor.
1070 -- @class                       function
1071 -- @name                        enum
1072 -- @param scheme        Scheme instance
1073 -- @param co            Configuration data
1074 -- @param c                     Configuration name
1075 -- @param s                     Section name
1076 -- @param o                     Enum name
1077 -- @param v                     Enum value
1078 -- @return                      Enum value instance
1079 enum = luci.util.class(option)
1080
1081 function enum.__init__(self, scheme, co, c, s, o, v)
1082         self.cref = { c, s, o, v }
1083         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1084         self.c    = self:_loadconf(co, c)
1085         self.s    = scheme
1086         self.t    = luci.uvl.TYPE_ENUM
1087 end