xml.lua

   1 #!/usr/bin/lua
   2 --[[
   3
   4 Copyright (c) 2007-2008 Mauro Iazzi
   5
   6 Permission is hereby granted, free of charge, to any person
   7 obtaining a copy of this software and associated documentation
   8 files (the "Software"), to deal in the Software without
   9 restriction, including without limitation the rights to use,
  10 copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 copies of the Software, and to permit persons to whom the
  12 Software is furnished to do so, subject to the following
  13 conditions:
  14
  15 The above copyright notice and this permission notice shall be
  16 included in all copies or substantial portions of the Software.
  17
  18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  20 OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  25 OTHER DEALINGS IN THE SOFTWARE.
  26
  27 --]]
  28
  29
  30 local xml_parser = {
  31
  32 strip_escapes = function (self, s)
  33         s = string.gsub(s, '&gt;', '>')
  34         s = string.gsub(s, '&lt;', '<')
  35         return s
  36 end,
  37
  38 parseargs = function (self, s)
  39         local arg = {}
  40         string.gsub(s, "([%w_]+)=([\"'])(.-)%2", function (w, _, a)
  41                 arg[self:strip_escapes(w)] = self:strip_escapes(a)
  42         end)
  43         return arg
  44 end,
  45
  46 collect = function (self, s)
  47         local stack = {}
  48         local top = {}
  49         table.insert(stack, top)
  50         local ni,c,label,xarg, empty
  51         local i, j = 1, 1
  52         while true do
  53                 ni,j,c,label,xarg, empty = string.find(s, "<(%/?)(%w+)(.-)(%/?)>", j)
  54                 if not ni then break end
  55                 local text = string.sub(s, i, ni-1)
  56                 if not string.find(text, "^%s*$") then
  57                         table.insert(top, text)
  58                 end
  59                 local inserted = nil
  60                 if empty == "/" then  -- empty element tag
  61                         inserted = {tag=label, attr=self:parseargs(xarg), empty=1}
  62                         table.insert(top, inserted)
  63                 elseif c == "" then   -- start tag
  64                         top = {tag=label, attr=self:parseargs(xarg)}
  65                         inserted = top
  66                         table.insert(stack, top)   -- new level
  67                 else  -- end tag
  68             local toclose = table.remove(stack)  -- remove top
  69                         top = stack[#stack]
  70                         if #stack < 1 then
  71                                 error("nothing to close with "..label)
  72                         end
  73                         if toclose.tag ~= label then
  74                                 error("trying to close "..toclose.label.." with "..label)
  75                         end
  76                         table.insert(top, toclose)
  77                 end
  78                 if inserted then
  79                         for a, v in pairs(inserted.attr) do
  80                                 if type(self[a])=='table' then
  81                                         self[a][v] = inserted
  82                                 end
  83                         end
  84                 end
  85                 i = j+1
  86         end
  87         local text = string.sub(s, i)
  88         if not string.find(text, "^%s*$") then
  89                 table.insert(stack[stack.n], text)
  90         end
  91         if #stack > 1 then
  92                 error("unclosed "..stack[stack.n].label)
  93         end
  94         return stack[1]
  95 end,
  96 }
  97
  98 return xml_parser