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 ERR = luci.uvl.errors
  59
  60
  61 --- Object constructor
  62 -- @class                       function
  63 -- @name                        UVL
  64 -- @param schemedir     Path to the scheme directory (optional)
  65 -- @return                      Instance object
  66 UVL = luci.util.class()
  67
  68 function UVL.__init__( self, schemedir )
  69         self.schemedir  = schemedir or default_schemedir
  70         self.packages   = { }
  71         self.beenthere  = { }
  72         self.uci                = luci.model.uci
  73         self.err                = luci.uvl.errors
  74         self.dep                = luci.uvl.dependencies
  75         self.datatypes  = luci.uvl.datatypes
  76 end
  77
  78
  79 --- Parse given scheme and return the scheme tree.
  80 -- @param scheme        Name of the scheme to parse
  81 -- @return                      Table containing the parsed scheme or nil on error
  82 -- @return                      String containing the reason for errors (if any)
  83 function UVL.get_scheme( self, scheme )
  84         if not self.packages[scheme] then
  85                 local ok, err = self:read_scheme( scheme )
  86                 if not ok then
  87                         return nil, err
  88                 end
  89         end
  90         return self.packages[scheme], nil
  91 end
  92
  93 --- Validate given configuration, section or option.
  94 -- @param config        Name of the configuration to validate
  95 -- @param section       Name of the section to validate (optional)
  96 -- @param option        Name of the option to validate (optional)
  97 -- @return                      Boolean indicating whether the given config validates
  98 -- @return                      String containing the reason for errors (if any)
  99 function UVL.validate( self, config, section, option )
 100         if config and section and option then
 101                 return self:validate_option( config, section, option )
 102         elseif config and section then
 103                 return self:validate_section( config, section )
 104         elseif config then
 105                 return self:validate_config( config )
 106         end
 107 end
 108
 109 --- Validate given configuration.
 110 -- @param config        Name of the configuration to validate
 111 -- @return                      Boolean indicating whether the given config validates
 112 -- @return                      String containing the reason for errors (if any)
 113 function UVL.validate_config( self, config, uci )
 114
 115         if not self.packages[config] then
 116                 local ok, err = self:read_scheme(config)
 117                 if not ok then
 118                         return false, err
 119                 end
 120         end
 121
 122         local co = luci.uvl.config( self, uci or config, uci and config )
 123         local sc = { }
 124
 125         self.beenthere = { }
 126
 127         if not co:config() then
 128                 return false, ERR.UCILOAD(co)
 129         end
 130
 131         local function _uci_foreach( type, func )
 132                 for k, v in pairs(co:config()) do
 133                         if v['.type'] == type then
 134                                 sc[type] = sc[type] + 1
 135                                 local ok, err = func( k, v )
 136                                 if not ok then co:error(err) end
 137                         end
 138                 end
 139         end
 140
 141         for k, v in pairs( self.packages[config].sections ) do
 142                 sc[k] = 0
 143                 _uci_foreach( k,
 144                         function(s)
 145                                 return self:_validate_section( co:section(s) )
 146                         end
 147                 )
 148         end
 149
 150         if STRICT_UNKNOWN_SECTIONS then
 151                 for k, v in pairs(co:config()) do
 152                         local so = co:section(k)
 153                         if not self.beenthere[so:cid()] then
 154                                 co:error(ERR.SECT_UNKNOWN(so))
 155                         end
 156                 end
 157         end
 158
 159         for _, k in ipairs(luci.util.keys(sc)) do
 160                 local so = co:section(k)
 161                 if so:scheme('required') and sc[k] == 0 then
 162                         co:error(ERR.SECT_REQUIRED(so))
 163                 elseif so:scheme('unique') and sc[k] > 1 then
 164                         co:error(ERR.SECT_UNIQUE(so))
 165                 end
 166         end
 167
 168         return co:ok(), co:errors()
 169 end
 170
 171 --- Validate given config section.
 172 -- @param config        Name of the configuration to validate
 173 -- @param section       Name of the section to validate
 174 -- @return                      Boolean indicating whether the given config validates
 175 -- @return                      String containing the reason for errors (if any)
 176 function UVL.validate_section( self, config, section, uci )
 177
 178         if not self.packages[config] then
 179                 local ok, err = self:read_scheme( config )
 180                 if not ok then
 181                         return false, err
 182                 end
 183         end
 184
 185         local co = luci.uvl.config( self, uci or config, uci and config )
 186         local so = co:section( section )
 187
 188         self.beenthere = { }
 189
 190         if not co:config() then
 191                 return false, ERR.UCILOAD(co)
 192         end
 193
 194         if so:config() then
 195                 return self:_validate_section( so )
 196         else
 197                 return false, ERR.SECT_NOTFOUND(so)
 198         end
 199 end
 200
 201 --- Validate given config option.
 202 -- @param config        Name of the configuration to validate
 203 -- @param section       Name of the section to validate
 204 -- @param option        Name of the option to validate
 205 -- @return                      Boolean indicating whether the given config validates
 206 -- @return                      String containing the reason for errors (if any)
 207 function UVL.validate_option( self, config, section, option, uci )
 208
 209         if not self.packages[config] then
 210                 local ok, err = self:read_scheme( config )
 211                 if not ok then
 212                         return false, err
 213                 end
 214         end
 215
 216         local co = luci.uvl.config( self, uci or config, uci and config )
 217         local so = co:section( section )
 218         local oo = so:option( option )
 219
 220         if not co then
 221                 return false, oerr:child(ERR.UCILOAD(config))
 222         end
 223
 224         if so:config() and oo:config() then
 225                 return self:_validate_option( oo )
 226         else
 227                 return false, ERR.OPT_NOTFOUND(oo)
 228         end
 229 end
 230
 231
 232 function UVL._validate_section( self, section )
 233
 234         if section:config() then
 235                 if section:scheme('named') == true and
 236                    section:config('.anonymous') == true
 237                 then
 238                         return false, ERR.SECT_NAMED(section)
 239                 end
 240
 241                 for _, v in ipairs(section:variables()) do
 242                         local ok, err = self:_validate_option( v )
 243                         if not ok then
 244                                 section:error(err)
 245                         end
 246                 end
 247
 248                 local ok, err = luci.uvl.dependencies.check( self, section )
 249                 if not ok then
 250                         section:error(err)
 251                 end
 252         else
 253                 return false, ERR.SECT_NOTFOUND(section)
 254         end
 255
 256         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 257                 for k, v in pairs(section:config()) do
 258                         local oo = section:option(k)
 259                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 260                                 section:error(ERR.OPT_NOTFOUND(oo))
 261                         end
 262                 end
 263         end
 264
 265         return section:ok(), section:errors()
 266 end
 267
 268 function UVL._validate_option( self, option, nodeps )
 269
 270         if not option:scheme() and not option:parent():scheme('dynamic') then
 271                 return false, option:error(ERR.OPT_UNKNOWN(option))
 272
 273         elseif option:scheme() then
 274                 if option:scheme('required') and not option:value() then
 275                         return false, option:error(ERR.OPT_REQUIRED(option))
 276
 277                 elseif option:value() then
 278                         local val = option:value()
 279
 280                         if option:scheme('type') == "reference" or
 281                            option:scheme('type') == "enum"
 282                         then
 283                                 if not option:scheme('values') or
 284                                    not option:scheme('values')[val]
 285                                 then
 286                                         return false, option:error( ERR.OPT_BADVALUE(
 287                                                 option, { val, table.concat(
 288                                                         luci.util.keys(option:scheme('values') or {}), ", "
 289                                                 ) }
 290                                         ) )
 291                                 end
 292                         elseif option:scheme('type') == "list" then
 293                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 294                                         return false, option:error(ERR.OPT_NOTLIST(option))
 295                                 end
 296                         elseif option:scheme('datatype') then
 297                                 local dt = option:scheme('datatype')
 298
 299                                 if self.datatypes[dt] then
 300                                         val = ( type(val) == "table" and val or { val } )
 301                                         for i, v in ipairs(val) do
 302                                                 if not self.datatypes[dt]( v ) then
 303                                                         return false, option:error(
 304                                                                 ERR.OPT_INVVALUE(option, {v, dt})
 305                                                         )
 306                                                 end
 307                                         end
 308                                 else
 309                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 310                                 end
 311                         end
 312                 end
 313
 314                 if not nodeps then
 315                         local ok, err = luci.uvl.dependencies.check( self, option )
 316                         if not ok then
 317                                 option:error(err)
 318                         end
 319                 end
 320
 321                 local ok, err = luci.uvl.validation.check( self, option )
 322                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 323                         return false, option:error(err)
 324                 end
 325         end
 326
 327         return option:ok(), option:errors()
 328 end
 329
 330 --- Find all parts of given scheme and construct validation tree.
 331 -- This is normally done on demand, so you don't have to call this function
 332 -- by yourself.
 333 -- @param scheme        Name of the scheme to parse
 334 function UVL.read_scheme( self, scheme )
 335
 336         local so = luci.uvl.scheme( self, scheme )
 337
 338         local schemes = { }
 339         local files = luci.fs.glob(self.schemedir .. '/*/' .. scheme)
 340
 341         if files then
 342                 for i, file in ipairs( files ) do
 343                         if not luci.fs.access(file) then
 344                                 return so:error(ERR.SME_READ(so,file))
 345                         end
 346
 347                         local uci = luci.model.uci.cursor()
 348                               uci:set_confdir( luci.fs.dirname(file) )
 349
 350                         local sd = uci:get_all( luci.fs.basename(file) )
 351
 352                         if not sd then
 353                                 return false, ERR.UCILOAD(so)
 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, ERR.UCILOAD(ref[1]) 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
 829 --- Object representation of a scheme.
 830 -- @class       scheme
 831 -- @cstyle      instance
 832 -- @name        luci.uvl.scheme
 833
 834 --- Scheme instance constructor.
 835 -- @class                       function
 836 -- @name                        scheme
 837 -- @param scheme        Scheme instance
 838 -- @param co            Configuration data
 839 -- @param c                     Configuration name
 840 -- @return                      Config instance
 841 scheme = luci.util.class(uvlitem)
 842
 843 function scheme.__init__(self, scheme, co, c)
 844         if not c then
 845                 c, co = co, nil
 846         end
 847
 848         if not co then
 849                 local uci = luci.model.uci.cursor()
 850                 co = uci:get_all(c)
 851         end
 852
 853         self.cref = { c }
 854         self.sref = { c }
 855         self.c    = co
 856         self.s    = scheme
 857         self.t    = luci.uvl.TYPE_SCHEME
 858 end
 859
 860 --- Add an error to scheme.
 861 -- @return      Scheme error context
 862 function scheme.error(self, ...)
 863         if not self.e then self.e = ERR.SCHEME( self ) end
 864         return self.e:child( ... )
 865 end
 866
 867 --- Get an associated config object.
 868 -- @return      Config instance
 869 function scheme.config(self)
 870         local co = luci.uvl.config( self.s, self.cref[1] )
 871               co.p = self
 872
 873         return co
 874 end
 875
 876 --- Get all section objects associated with this scheme.
 877 -- @return      Table containing all associated luci.uvl.section instances
 878 function scheme.sections(self)
 879         local v = { }
 880         if self.s.packages[self.sref[1]].sections then
 881                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 882                         table.insert( v, luci.uvl.option(
 883                                 self.s, self.c, self.cref[1], self.cref[2], o
 884                         ) )
 885                 end
 886         end
 887         return v
 888 end
 889
 890 --- Get an associated section object.
 891 -- @param s     Section to select
 892 -- @return      Section instance
 893 function scheme.section(self, s)
 894         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 895               so.p = self
 896
 897         return so
 898 end
 899
 900
 901 --- Object representation of a config.
 902 -- @class       config
 903 -- @cstyle      instance
 904 -- @name        luci.uvl.config
 905
 906 --- Config instance constructor.
 907 -- @class                       function
 908 -- @name                        config
 909 -- @param scheme        Scheme instance
 910 -- @param co            Configuration data
 911 -- @param c                     Configuration name
 912 -- @return                      Config instance
 913 config = luci.util.class(uvlitem)
 914
 915 function config.__init__(self, scheme, co, c)
 916         if not c then
 917                 c, co = co, nil
 918         end
 919
 920         if not co then
 921                 local uci = luci.model.uci.cursor()
 922                 co = uci:get_all(c)
 923         end
 924
 925         self.cref = { c }
 926         self.sref = { c }
 927         self.c    = co
 928         self.s    = scheme
 929         self.t    = luci.uvl.TYPE_CONFIG
 930 end
 931
 932 --- Get all section objects associated with this config.
 933 -- @return      Table containing all associated luci.uvl.section instances
 934 function config.sections(self)
 935         local v = { }
 936         if self.s.packages[self.sref[1]].sections then
 937                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 938                         table.insert( v, luci.uvl.option(
 939                                 self.s, self.c, self.cref[1], self.cref[2], o
 940                         ) )
 941                 end
 942         end
 943         return v
 944 end
 945
 946 --- Get an associated section object.
 947 -- @param s     Section to select
 948 -- @return      Section instance
 949 function config.section(self, s)
 950         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 951               so.p = self
 952
 953         return so
 954 end
 955
 956
 957 --- Object representation of a scheme/config section.
 958 -- @class       module
 959 -- @cstyle      instance
 960 -- @name        luci.uvl.section
 961
 962 --- Section instance constructor.
 963 -- @class                       function
 964 -- @name                        section
 965 -- @param scheme        Scheme instance
 966 -- @param co            Configuration data
 967 -- @param c                     Configuration name
 968 -- @param s                     Section name
 969 -- @return                      Section instance
 970 section = luci.util.class(uvlitem)
 971
 972 function section.__init__(self, scheme, co, c, s)
 973         self.cref = { c, s }
 974         self.sref = { c, co and co[s] and co[s]['.type'] or s }
 975         self.c    = co
 976         self.s    = scheme
 977         self.t    = luci.uvl.TYPE_SECTION
 978 end
 979
 980 --- Get all option objects associated with this section.
 981 -- @return      Table containing all associated luci.uvl.option instances
 982 function section.variables(self)
 983         local v = { }
 984         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
 985                 for o, _ in pairs(
 986                         self.s.packages[self.sref[1]].variables[self.sref[2]]
 987                 ) do
 988                         table.insert( v, luci.uvl.option(
 989                                 self.s, self.c, self.cref[1], self.cref[2], o
 990                         ) )
 991                 end
 992         end
 993         return v
 994 end
 995
 996 --- Get an associated option object.
 997 -- @param o     Option to select
 998 -- @return      Option instance
 999 function section.option(self, o)
1000         local oo = luci.uvl.option( self.s, self.c, self.cref[1], self.cref[2], o )
1001               oo.p = self
1002
1003         return oo
1004 end
1005
1006
1007 --- Object representation of a scheme/config option.
1008 -- @class       module
1009 -- @cstyle      instance
1010 -- @name        luci.uvl.option
1011
1012 --- Section instance constructor.
1013 -- @class                       function
1014 -- @name                        option
1015 -- @param scheme        Scheme instance
1016 -- @param co            Configuration data
1017 -- @param c                     Configuration name
1018 -- @param s                     Section name
1019 -- @param o                     Option name
1020 -- @return                      Option instance
1021 option = luci.util.class(uvlitem)
1022
1023 function option.__init__(self, scheme, co, c, s, o)
1024         self.cref = { c, s, o }
1025         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1026         self.c    = co
1027         self.s    = scheme
1028         self.t    = luci.uvl.TYPE_OPTION
1029 end
1030
1031 --- Get the value of this option.
1032 -- @return      The associated configuration value
1033 function option.value(self)
1034         return self:config()
1035 end
1036
1037 --- Get the associated section information in scheme.
1038 -- @return      Table containing the scheme properties
1039 function option.section(self)
1040         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1041 end
1042
1043 --- Construct an enum object instance from given or default value.
1044 -- @param v     Value to select
1045 -- @return      Enum instance for selected value
1046 function option.enum(self, val)
1047         return enum(
1048                 self.s, self.c,
1049                 self.cref[1], self.cref[2], self.cref[3],
1050                 val or self:value()
1051         )
1052 end
1053
1054
1055 --- Object representation of a enum value.
1056 -- @class       module
1057 -- @cstyle      instance
1058 -- @name        luci.uvl.enum
1059
1060 --- Section instance constructor.
1061 -- @class                       function
1062 -- @name                        enum
1063 -- @param scheme        Scheme instance
1064 -- @param co            Configuration data
1065 -- @param c                     Configuration name
1066 -- @param s                     Section name
1067 -- @param o                     Enum name
1068 -- @param v                     Enum value
1069 -- @return                      Enum value instance
1070 enum = luci.util.class(option)
1071
1072 function enum.__init__(self, scheme, co, c, s, o, v)
1073         self.cref = { c, s, o, v }
1074         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1075         self.c    = co
1076         self.s    = scheme
1077         self.t    = luci.uvl.TYPE_ENUM
1078 end