* luci/libs: uvl: implement get_scheme() and get_dependencies()
[project/luci.git] / 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 function _parse_reference( r, c, s, o )
20 local ref = { }
21 local vars = {
22 config = ( c or '$config' ),
23 section = ( s or '$section' ),
24 option = ( o or '$option' )
25 }
26
27 for i, v in ipairs(luci.util.split(r,".")) do
28 table.insert(ref, (v:gsub( "%$(.+)", function(n) return vars[n] end )))
29 end
30
31 if c or s then
32 if #ref == 1 and c and s then
33 ref = { c, s, ref[1] }
34 elseif #ref == 2 and c then
35 ref = { c, unpack(ref) }
36 elseif #ref ~= 3 then
37 ref = nil
38 end
39 else
40 if #ref == 1 then
41 ref = { '$config', '$section', ref[1] }
42 elseif #ref == 2 then
43 ref = { '$config', unpack(ref) }
44 elseif #ref ~= 3 then
45 ref = nil
46 end
47 end
48
49 return ref
50 end
51
52 function check( self, object, nodeps )
53
54 if not self.beenthere[object:cid()] then
55 self.beenthere[object:cid()] = true
56 else
57 return false, "Recursive dependency for '" .. object:sid() .. "' found"
58 end
59
60 local item = object.type == luci.uvl.TYPE_SECTION
61 and object:section() or object:option()
62
63 if item.depends then
64 local ok = false
65 local valid, err = false,
66 string.format( 'In dependency check for %s "%s":',
67 ( object.type == luci.uvl.TYPE_SECTION and "section" or "option" ),
68 object:cid() )
69
70 for _, dep in ipairs(item.depends) do
71 local subcondition = true
72 for k, v in pairs(dep) do
73 -- XXX: better error
74 local ref = _parse_reference( k, unpack(object.cref) )
75
76 if not ref then
77 return false, "Ambiguous dependency reference '" .. k ..
78 "' for object '" .. object:sid() .. "' given"
79 end
80
81 local option = luci.uvl.option(
82 self, object.config,
83 object.config[ref[2]]
84 and object.config[ref[2]]['.type']
85 or object.sref[2],
86 ref[1], ref[2], ref[3]
87 )
88
89 valid, err2 = self:_validate_option( option, true )
90 if valid then
91 if not (
92 ( type(v) == "boolean" and object.config[ref[2]][ref[3]] ) or
93 ( ref[3] and object.config[ref[2]][ref[3]] ) == v
94 ) then
95 subcondition = false
96 err = err .. "\n" ..
97 self.log.dump_dependency( dep, ref, v )
98 break
99 end
100 else
101 subcondition = false
102 err = err .. "\n" ..
103 self.log.dump_dependency( dep, ref, nil, err2 )
104 break
105 end
106 end
107
108 if subcondition then
109 return true
110 end
111 end
112
113 return false, err
114 end
115
116 return true
117 end