--- @module Module providing a non-validating XML stream parser in Lua.
|
--
|
-- Features:
|
-- =========
|
--
|
-- * Tokenises well-formed XML (relatively robustly)
|
-- * Flexible handler based event API (see below)
|
-- * Parses all XML Infoset elements - ie.
|
-- - Tags
|
-- - Text
|
-- - Comments
|
-- - CDATA
|
-- - XML Decl
|
-- - Processing Instructions
|
-- - DOCTYPE declarations
|
-- * Provides limited well-formedness checking
|
-- (checks for basic syntax & balanced tags only)
|
-- * Flexible whitespace handling (selectable)
|
-- * Entity Handling (selectable)
|
--
|
-- Limitations:
|
-- ============
|
--
|
-- * Non-validating
|
-- * No charset handling
|
-- * No namespace support
|
-- * Shallow well-formedness checking only (fails
|
-- to detect most semantic errors)
|
--
|
-- API:
|
-- ====
|
--
|
-- The parser provides a partially object-oriented API with
|
-- functionality split into tokeniser and handler components.
|
--
|
-- The handler instance is passed to the tokeniser and receives
|
-- callbacks for each XML element processed (if a suitable handler
|
-- function is defined). The API is conceptually similar to the
|
-- SAX API but implemented differently.
|
--
|
-- XML data is passed to the parser instance through the 'parse'
|
-- method (Note: must be passed a single string currently)
|
--
|
-- License:
|
-- ========
|
--
|
-- This code is freely distributable under the terms of the [MIT license](LICENSE).
|
--
|
--
|
--@author Paul Chakravarti (paulc@passtheaardvark.com)
|
--@author Manoel Campos da Silva Filho
|
local xml2lua = { _VERSION = "1.6-1" }
|
local XmlParser = require("XmlParser")
|
|
---Recursivelly prints a table in an easy-to-ready format
|
--@param tb The table to be printed
|
--@param level the indentation level to start with
|
local function printableInternal(tb, level)
|
if tb == nil then
|
return
|
end
|
|
level = level or 1
|
local spaces = string.rep(' ', level*2)
|
for k,v in pairs(tb) do
|
if type(v) == "table" then
|
print(spaces .. k)
|
printableInternal(v, level+1)
|
else
|
print(spaces .. k..'='..v)
|
end
|
end
|
end
|
|
---Instantiates a XmlParser object to parse a XML string
|
--@param handler Handler module to be used to convert the XML string
|
--to another formats. See the available handlers at the handler directory.
|
-- Usually you get an instance to a handler module using, for instance:
|
-- local handler = require("xmlhandler/tree").
|
--@return a XmlParser object used to parse the XML
|
--@see XmlParser
|
function xml2lua.parser(handler)
|
if handler == xml2lua then
|
error("You must call xml2lua.parse(handler) instead of xml2lua:parse(handler)")
|
end
|
|
local options = {
|
--Indicates if whitespaces should be striped or not
|
stripWS = 1,
|
expandEntities = 1,
|
errorHandler = function(errMsg, pos)
|
error(string.format("%s [char=%d]\n", errMsg or "Parse Error", pos))
|
end
|
}
|
|
return XmlParser.new(handler, options)
|
end
|
|
---Recursivelly prints a table in an easy-to-ready format
|
--@param tb The table to be printed
|
function xml2lua.printable(tb)
|
printableInternal(tb)
|
end
|
|
---Handler to generate a string prepresentation of a table
|
--Convenience function for printHandler (Does not support recursive tables).
|
--@param t Table to be parsed
|
--@return a string representation of the table
|
function xml2lua.toString(t)
|
local sep = ''
|
local res = ''
|
if type(t) ~= 'table' then
|
return t
|
end
|
|
for k,v in pairs(t) do
|
if type(v) == 'table' then
|
v = xml2lua.toString(v)
|
end
|
res = res .. sep .. string.format("%s=%s", k, v)
|
sep = ','
|
end
|
res = '{'..res..'}'
|
|
return res
|
end
|
|
--- Loads an XML file from a specified path
|
-- @param xmlFilePath the path for the XML file to load
|
-- @return the XML loaded file content
|
function xml2lua.loadFile(xmlFilePath)
|
local f, e = io.open(xmlFilePath, "r")
|
if f then
|
--Gets the entire file content and stores into a string
|
local content = f:read("*a")
|
f:close()
|
return content
|
end
|
|
error(e)
|
end
|
|
---Gets an _attr element from a table that represents the attributes of an XML tag,
|
--and generates a XML String representing the attibutes to be inserted
|
--into the openning tag of the XML
|
--
|
--@param attrTable table from where the _attr field will be got
|
--@return a XML String representation of the tag attributes
|
local function attrToXml(attrTable)
|
local s = ""
|
attrTable = attrTable or {}
|
|
for k, v in pairs(attrTable) do
|
s = s .. " " .. k .. "=" .. '"' .. v .. '"'
|
end
|
return s
|
end
|
|
---Gets the first key of a given table
|
local function getSingleChild(tb)
|
local count = 0
|
for _ in pairs(tb) do
|
count = count + 1
|
end
|
if (count == 1) then
|
for k, _ in pairs(tb) do
|
return k
|
end
|
end
|
return nil
|
end
|
|
---Gets the first value of a given table
|
local function getFirstValue(tb)
|
if type(tb) == "table" then
|
for _, v in pairs(tb) do
|
return v
|
end
|
return nil
|
end
|
|
return tb
|
end
|
|
xml2lua.pretty = true
|
|
function xml2lua.getSpaces(level)
|
local spaces = ''
|
if (xml2lua.pretty) then
|
spaces = string.rep(' ', level * 2)
|
end
|
return spaces
|
end
|
|
function xml2lua.addTagValueAttr(tagName, tagValue, attrTable, level)
|
local attrStr = attrToXml(attrTable)
|
local spaces = xml2lua.getSpaces(level)
|
if (tagValue == '') then
|
table.insert(xml2lua.xmltb, spaces .. '<' .. tagName .. attrStr .. '/>')
|
else
|
table.insert(xml2lua.xmltb, spaces .. '<' .. tagName .. attrStr .. '>' .. tostring(tagValue) .. '</' .. tagName .. '>')
|
end
|
end
|
|
function xml2lua.startTag(tagName, attrTable, level)
|
local attrStr = attrToXml(attrTable)
|
local spaces = xml2lua.getSpaces(level)
|
if (tagName ~= nil) then
|
table.insert(xml2lua.xmltb, spaces .. '<' .. tagName .. attrStr .. '>')
|
end
|
end
|
|
function xml2lua.endTag(tagName, level)
|
local spaces = xml2lua.getSpaces(level)
|
if (tagName ~= nil) then
|
table.insert(xml2lua.xmltb, spaces .. '</' .. tagName .. '>')
|
end
|
end
|
|
function xml2lua.isChildArray(obj)
|
for tag, _ in pairs(obj) do
|
if (type(tag) == 'number') then
|
return true
|
end
|
end
|
return false
|
end
|
|
function xml2lua.isTableEmpty(obj)
|
for k, _ in pairs(obj) do
|
if (k ~= '_attr') then
|
return false
|
end
|
end
|
return true
|
end
|
|
function xml2lua.parseTableToXml(obj, tagName, level)
|
if (tagName ~= '_attr') then
|
if (type(obj) == 'table') then
|
if (xml2lua.isChildArray(obj)) then
|
for _, value in pairs(obj) do
|
xml2lua.parseTableToXml(value, tagName, level)
|
end
|
elseif xml2lua.isTableEmpty(obj) then
|
xml2lua.addTagValueAttr(tagName, "", obj._attr, level)
|
else
|
xml2lua.startTag(tagName, obj._attr, level)
|
for tag, value in pairs(obj) do
|
xml2lua.parseTableToXml(value, tag, level + 1)
|
end
|
xml2lua.endTag(tagName, level)
|
end
|
else
|
xml2lua.addTagValueAttr(tagName, obj, nil, level)
|
end
|
end
|
end
|
|
---Converts a Lua table to a XML String representation.
|
--@param tb Table to be converted to XML
|
--@param tableName Name of the table variable given to this function,
|
-- to be used as the root tag. If a value is not provided
|
-- no root tag will be created.
|
--@param level Only used internally, when the function is called recursively to print indentation
|
--
|
--@return a String representing the table content in XML
|
function xml2lua.toXml(tb, tableName, level)
|
xml2lua.xmltb = {}
|
level = level or 0
|
local singleChild = getSingleChild(tb)
|
tableName = tableName or singleChild
|
|
if (singleChild) then
|
xml2lua.parseTableToXml(getFirstValue(tb), tableName, level)
|
else
|
xml2lua.parseTableToXml(tb, tableName, level)
|
end
|
|
if (xml2lua.pretty) then
|
return table.concat(xml2lua.xmltb, '\n')
|
end
|
return table.concat(xml2lua.xmltb)
|
end
|
|
return xml2lua
|
