propertylist.lua

local assert,error,setmetatable,tonumber = assert,error,setmetatable,tonumber
local table = require "table"
local io = require "io"
local lxp = require "lxp"
local base64 = require "base64"

module "propertylist"

array_metatable = {}
dictionary_metatable = {}

local function callback_EndElement(p,name,attr)
  local callbacks = p:getcallbacks()
  assert(name == callbacks.current.tagname,"tag name mismatch: "..name.."<->"..callbacks.current.tagname)
  local handler = callbacks.current.EndElement
  callbacks.current = callbacks.current.parent
  if handler then
    handler()
  end
end
local function callback_CharacterData(p,s)
  local callbacks = p:getcallbacks()
  if callbacks.current.CharacterData then
    callbacks.current.CharacterData(s)
  end
end
local function callback_StartElement(p,name,attr)
  local callbacks = p:getcallbacks()
  callbacks.current = {
    tagname = name,
    parent = callbacks.current,
    currentDict = callbacks.current and callbacks.current.currentDict
  }
  if name == "plist" then
    callbacks.current.valueHandler = function(a)
      callbacks.root = a
    end
  elseif name == "key" then
    local key = ""
    callbacks.current.CharacterData = function(k)
      key = k
    end
    local currentDict = callbacks.current.parent.currentDict
    callbacks.current.EndElement = function()
      callbacks.current.valueHandler = function(a)
        currentDict[key] = a
      end
    end
  elseif name == "true" then
    callbacks.current.parent.valueHandler(true)
  elseif name == "false" then
    callbacks.current.parent.valueHandler(false)
  elseif name == "real" or name == "integer" then
    callbacks.current.CharacterData = function(x)
      callbacks.current.parent.valueHandler(tonumber(x))
    end
  elseif name == "string" or name == "date" then
    callbacks.current.CharacterData = function(x)
      callbacks.current.parent.valueHandler(x)
    end
  elseif name == "data" then
    callbacks.current.CharacterData = function(x)
      callbacks.current.parent.valueHandler(base64.decode(x))
    end
  elseif name == "array" then
    local t = {}
    callbacks.current.valueHandler = function(a)
      table.insert(t,a)
    end
    callbacks.current.EndElement = function()
      callbacks.current.valueHandler(setmetatable(t,array_metatable))
    end
  elseif name == "dict" then
    local currentDict = {}
    callbacks.current.currentDict = currentDict
    callbacks.current.EndElement = function()
      callbacks.current.valueHandler(setmetatable(currentDict,dictionary_metatable))
    end
  else
    error("unknown tag:"..name)
  end
end

function parse(data)
  local callbacks = {
    StartElement = callback_StartElement,
    CharacterData = callback_CharacterData,
    EndElement = callback_EndElement,
    current = nil,
    root = nil
  }
  local parser = lxp.new(callbacks)
  parser:parse(data)
  parser:close()
  return callbacks.root
end

function parsefile(filename)
  local f = assert(io.open(filename))
  local data = f:read("*a")
  f:close()
  return parse(data)
end