libs/uvl/luasrc/uvl/dependencies.lua

   1 --[[
   2
   3 UCI Validation Layer - Dependency helper
   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 module( "luci.uvl.dependencies", package.seeall )
  18
  19 local function _assert( condition, fmt, ... )
  20         if not condition then
  21                 return assert( nil, string.format( fmt, ... ) )
  22         else
  23                 return condition
  24         end
  25 end
  26
  27
  28 function _parse_reference( r, c, s, o )
  29         local ref  = { }
  30         local vars = {
  31                 config  = c,
  32                 section = s,
  33                 option  = o
  34         }
  35
  36         for i, v in ipairs(luci.util.split(r,".")) do
  37                 table.insert( ref, (v:gsub( "%$(.+)", function(n) return vars[n] end )) )
  38         end
  39
  40         if #ref == 1 and c and s then
  41                 ref = { c, s, ref[1] }
  42         elseif #ref == 2 and c then
  43                 ref = { c, unpack(ref) }
  44         elseif #ref ~= 3 then
  45                 ref = nil
  46         end
  47
  48         return ref
  49 end
  50
  51 function check( self, object, nodeps )
  52
  53         if not self.beenthere[object:cid()] then
  54                 self.beenthere[object:cid()] = true
  55         else
  56                 return false, "Recursive dependency for '" .. object:sid() .. "' found"
  57         end
  58
  59         local item = object.type == luci.uvl.TYPE_SECTION
  60                 and object:section() or object:option()
  61
  62         if item.depends then
  63                 local ok = false
  64                 local valid, err
  65
  66                 for _, dep in ipairs(item.depends) do
  67                         local subcondition = true
  68                         for k, v in pairs(dep) do
  69                                 -- XXX: better error
  70                                 local ref = _parse_reference( k, unpack(object.cref) )
  71
  72                                 if not ref then
  73                                         return false, "Ambiguous dependency reference '" .. k ..
  74                                                 "' for object '" .. object:sid() .. "' given"
  75                                 end
  76
  77                                 local option = luci.uvl.option(
  78                                         self, object.config,
  79                                         object.config[ref[2]]
  80                                                 and object.config[ref[2]]['.type']
  81                                                 or  object.sref[2],
  82                                         ref[1], ref[2], ref[3]
  83                                 )
  84
  85                                 valid, err = self:_validate_option( option, true )
  86                                 if valid then
  87                                         if not (
  88                                                 ( type(v) == "boolean" and object.config[ref[2]][ref[3]] ) or
  89                                                 ( ref[3] and object.config[ref[2]][ref[3]] ) == v
  90                                         ) then
  91                                                 subcondition = false
  92                                                 err = type(v) ~= "boolean"
  93                                                         and "Option '" .. table.concat( ref, "." ) ..
  94                                                                 "' doesn't match requested value '" .. v .. '"'
  95                                                         or  "Option '" .. table.concat( ref, "." ) ..
  96                                                                 "' has no value"
  97
  98                                                 break
  99                                         end
 100                                 else
 101                                         subcondition = false
 102                                         break
 103                                 end
 104                         end
 105
 106                         if subcondition then
 107                                 return true
 108                         end
 109                 end
 110
 111                 return false, err
 112         end
 113
 114         return true
 115 end