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