Closes #25

Adds xml2lua.toXml() function to convert a table to an XML representation

Author: manoelcampos

example1.lua

@@ -33,4 +33,4 @@ for i, p in pairs(people) do
 end
 
 --Recursivelly prints the table in an easy-to-ready format
---xml2lua.printable(handler.root)
+--xml2lua.printable(handler.root)

example3.lua

@@ -10,10 +10,10 @@ local xml2lua = require("xml2lua")
 --Uses a handler that converts the XML to a Lua table
 local handler = require("xmlhandler.tree")
 
+local xml = "<tag><tag1/><tag1/></tag>"
 --local xml = "<tag><tag1/></tag>"
---local xml = "<tag><tag1/><tag1/></tag>"
 --local xml = "<tag><tag1>A</tag1><tag1>B</tag1></tag>"
-local xml = "<tag><tag1>A</tag1></tag>"
+--local xml = "<tag><tag1>A</tag1></tag>"
 
 --Instantiates the XML parser
 local parser = xml2lua.parser(handler)

example4-table2xml.lua

@@ -0,0 +1,21 @@
+#!/usr/bin/env lua
+
+---Sample application showing how to convert a Lua Table to an XML representation
+--@author Manoel Campos da Silva Filho - http://manoelcampos.com
+
+local xml2lua = require("xml2lua")
+
+local people = {
+    person = {
+        {_attr={type="natural"}, name="Manoel", city="Palmas-TO"},
+        {_attr={type="natural"}, name="Breno", city="Palmas-TO"},
+        {_attr={type="legal"}, name="University of Brasília", city="Brasília-DF"}
+    }
+}
+
+print("People Table\n")
+xml2lua.printable(people)
+print("\n------------------------------------------------------\n")
+
+print("XML Representation\n")
+print(xml2lua.toXml(people, "people"))

xml2lua-1.2-4.rockspec renamed to xml2lua-1.3-0.rockspec

@@ -1,8 +1,8 @@
 package = "xml2lua"
-version = "1.2-4"
+version = "1.3-0"
 source = {
    url = "git://github.com/manoelcampos/xml2lua",
-   tag = "v1.2-4"
+   tag = "v1.3-0"
 }
 description = {
    summary = "An XML Parser written entirely in Lua that works for Lua 5.1 to 5.3",

xml2lua.lua

@@ -138,4 +138,76 @@ function xml2lua.loadFile(xmlFilePath)
     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 = ""
+  local 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 getFirstKey(tb)
+   if type(tb) == "table" then
+      for k, v in pairs(tb) do
+          return k
+      end
+      return nil
+   end
+
+   return tb
+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.
+--@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)
+  local level = level or 0
+  local firstLevel = level
+  local spaces = string.rep(' ', level*2)
+  local xmltb = level == 0 and {'<'..tableName..'>'} or {}
+
+  for k, v in pairs(tb) do
+      if type(v) == "table" then
+         --If the keys of the table are a number, it represents an array
+         if type(k) == "number" then
+            local attrs = attrToXml(v._attr)
+            v._attr = nil
+            table.insert(xmltb, 
+                spaces..'<'..tableName..attrs..'>\n'..xml2lua.toXml(v, tableName, level+1)..
+                '\n'..spaces..'</'..tableName..'>') 
+         else 
+            level = level + 1
+            if type(getFirstKey(v)) == "number" then 
+               table.insert(xmltb, spaces..xml2lua.toXml(v, k, level))
+            else
+              table.insert(
+                 xmltb, 
+                 spaces..'<'..k..'>\n'.. xml2lua.toXml(v, level+1)..
+                 '\n'..spaces..'</'..k..'>')
+            end
+         end
+      else
+         table.insert(xmltb, spaces..'<'..k..'>'..tostring(v)..'</'..k..'>')
+      end
+  end
+
+  if firstLevel == 0 then
+     table.insert(xmltb, '</'..tableName..'>\n')
+  end
+  return table.concat(xmltb, "\n")
+end
+
 return xml2lua