--..module(...,package.seeall)
--
-- Overview:
-- =========
-- Standard XML event handler(s) for XML parser module (xml.lua)
--
-- Features:
-- =========
-- printHandler - Generate XML event trace
-- domHandler - Generate DOM-like node tree
-- simpleTreeHandler - Generate 'simple' node tree
-- simpleTeXhandler - SAX like handler with support for CSS selectros
--
-- API:
-- ====
-- Must be called as handler function from xmlParser
-- and implement XML event callbacks (see xmlParser.lua
-- for callback API definition)
--
-- printHandler:
-- -------------
--
-- printHandler prints event trace for debugging
--
-- domHandler:
-- -----------
--
-- domHandler generates a DOM-like node tree structure with
-- a single ROOT node parent - each node is a table comprising
-- fields below.
--
-- node = { _name = <Element Name>,
-- _type = ROOT|ELEMENT|TEXT|COMMENT|PI|DECL|DTD,
-- _attr = { Node attributes - see callback API },
-- _parent = <Parent Node>
-- _children = { List of child nodes - ROOT/NODE only }
-- }
--
-- The dom structure is capable of representing any valid XML document
--
-- simpleTreeHandler
-- -----------------
--
-- simpleTreeHandler is a simplified handler which attempts
-- to generate a more 'natural' table based structure which
-- supports many common XML formats.
--
-- The XML tree structure is mapped directly into a recursive
-- table structure with node names as keys and child elements
-- as either a table of values or directly as a string value
-- for text. Where there is only a single child element this
-- is inserted as a named key - if there are multiple
-- elements these are inserted as a vector (in some cases it
-- may be preferable to always insert elements as a vector
-- which can be specified on a per element basis in the
-- options). Attributes are inserted as a child element with
-- a key of '_attr'.
--
-- Only Tag/Text & CDATA elements are processed - all others
-- are ignored.
--
-- This format has some limitations - primarily
--
-- * Mixed-Content behaves unpredictably - the relationship
-- between text elements and embedded tags is lost and
-- multiple levels of mixed content does not work
-- * If a leaf element has both a text element and attributes
-- then the text must be accessed through a vector (to
-- provide a container for the attribute)
--
-- In general however this format is relatively useful.
--
-- It is much easier to understand by running some test
-- data through 'textxml.lua -simpletree' than to read this)
--
-- Options
-- =======
-- simpleTreeHandler.options.noReduce = { <tag> = bool,.. }
--
-- - Nodes not to reduce children vector even if only
-- one child
--
-- domHandler.options.(comment|pi|dtd|decl)Node = bool
--
-- - Include/exclude given node types
--
-- Usage
-- =====
-- Pased as delegate in xmlParser constructor and called
-- as callback by xmlParser:parse(xml) method.
--
-- See textxml.lua for examples
-- License:
-- ========
--
-- This code is freely distributable under the terms of the Lua license
-- (<a href="http://www.lua.org/copyright.html">http://www.lua.org/copyright.html</a>)
--
-- History
-- =======
-- $Id: handler.lua,v 1.1.1.1 2001/11/28 06:11:33 paulc Exp $
--
-- $Log: handler.lua,v $
-- Revision 1.1.1.1 2001/11/28 06:11:33 paulc
-- Initial Import
--@author Paul Chakravarti (paulc@passtheaardvark.com)<p/>
---Handler to generate a string prepresentation of a table
--Convenience function for printHandler (Does not support recursive tables).
--@param t Table to be parsed
--@returns Returns a string representation of table
local M = {}
local stack
local entities
if kpse then
stack = require("luaxml-stack")
entities = require("luaxml-entities")
else
stack = require("luaxml.stack")
entities = require("luaxml.entities")
end
local function showTable(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 = showTable(v)
end
res = res .. sep .. string.format("%s=%s",k,v)
sep = ','
end
res = '{'..res..'}'
return res
end
M.showTable = showTable
---Handler to generate a simple event trace
local printHandler = function()
local obj = {}
obj.starttag = function(self,t,a,s,e)
io.write("Start : "..t.."\n")
if a then
for k,v in pairs(a) do
io.write(string.format(" + %s='%s'\n",k,v))
end
end
end
obj.endtag = function(self,t,s,e)
io.write("End : "..t.."\n")
end
obj.text = function(self,t,s,e)
io.write("Text : "..t.."\n")
end
obj.cdata = function(self,t,s,e)
io.write("CDATA : "..t.."\n")
end
obj.comment = function(self,t,s,e)
io.write("Comment : "..t.."\n")
end
obj.dtd = function(self,t,a,s,e)
io.write("DTD : "..t.."\n")
if a then
for k,v in pairs(a) do
io.write(string.format(" + %s='%s'\n",k,v))
end
end
end
obj.pi = function(self,t,a,s,e)
io.write("PI : "..t.."\n")
if a then
for k,v in pairs(a) do
io. write(string.format(" + %s='%s'\n",k,v))
end
end
end
obj.decl = function(self,t,a,s,e)
io.write("XML Decl : "..t.."\n")
if a then
for k,v in pairs(a) do
io.write(string.format(" + %s='%s'\n",k,v))
end
end
end
return obj
end
M.printHandler = printHandler
---Handler to generate a lua table from a XML content string
local function simpleTreeHandler()
local obj = {}
obj.root = {}
obj.stack = {obj.root;n=1}
obj.options = {noreduce = {}}
obj.reduce = function(self,node,key,parent)
-- Recursively remove redundant vectors for nodes
-- with single child elements
for k,v in pairs(node) do
if type(v) == 'table' then
self:reduce(v,k,node)
end
end
if #node == 1 and not self.options.noreduce[key] and
node._attr == nil then
parent[key] = node[1]
else
node.n = nil
end
end
obj.starttag = function(self,t,a)
local node = {}
if self.parseAttributes == true then
node._attr=a
end
local current = self.stack[#self.stack]
if current[t] then
table.insert(current[t],node)
else
current[t] = {node;n=1}
end
table.insert(self.stack,node)
end
obj.endtag = function(self,t,s)
local current = self.stack[#self.stack]
local prev = self.stack[#self.stack-1]
if not prev[t] then
error("XML Error - Unmatched Tag ["..s..":"..t.."]\n")
end
if prev == self.root then
-- Once parsing complete recursively reduce tree
self:reduce(prev,nil,nil)
end
table.remove(self.stack)
end
obj.text = function(self,t)
local current = self.stack[#self.stack]
table.insert(current,t)
end
obj.cdata = obj.text
return obj
end
M.simpleTreeHandler = simpleTreeHandler
--- domHandler
local function domHandler()
local obj = {}
local decode = entities.decode
obj.options = {commentNode=1,piNode=1,dtdNode=1,declNode=1, voidElements = {}}
obj.root = { _children = {n=0}, _type = "ROOT" }
obj.current = obj.root
obj.starttag = function(self,t,a)
local newattr
if a then
newattr = {}
for k,v in pairs(a) do
newattr[k] = decode(v)
end
end
local node = { _type = 'ELEMENT',
_name = t,
_attr = newattr,
_parent = self.current,
_children = {n=0} }
table.insert(self.current._children,node)
-- close void element
if not self.options.voidElements[t] then
self.current = node
else
table.remove(self._xml._stack)
end
end
obj.endtag = function(self,t,s)
if not self.options.voidElements[t] then
if t ~= self.current._name then
error("XML Error - Unmatched Tag ["..s..":"..t.."]\n")
end
self.current = self.current._parent
end
end
obj.text = function(self,t)
local text = decode(t)
local node = {
_type = "TEXT",
_parent = self.current,
_text = text
}
table.insert(self.current._children,node)
end
obj.comment = function(self,t)
if self.options.commentNode then
local node = { _type = "COMMENT",
_parent = self.current,
_text = t }
table.insert(self.current._children,node)
end
end
obj.pi = function(self,t,a)
if self.options.piNode then
local node = { _type = "PI",
_name = t,
_attr = a,
_parent = self.current }
table.insert(self.current._children,node)
end
end
obj.decl = function(self,t,a)
if self.options.declNode then
local node = { _type = "DECL",
_name = t,
_attr = a,
_parent = self.current }
table.insert(self.current._children,node)
end
end
obj.dtd = function(self,t,a)
if self.options.dtdNode then
local node = { _type = "DTD",
_name = t,
_attr = a,
_parent = self.current }
table.insert(self.current._children,node)
end
end
obj.cdata = function(self,t)
local node = { _type = "CDATA",
_parent = self.current,
_text = decode(t) }
table.insert(self.current._children,node)
end
return obj
end
M.domHandler = domHandler
--
local simpleTeXhandler=function()
local obj={}
local _stack=stack.Stack:Create()
obj.starttag = function(self,t,a,s,e)
local tag = {t}
local getAtt = function(att)
if a[att] then
return att.."="..a[att]
end
return nil
end
if type(a) == "table" then
table.insert(tag,getAtt("id"))
table.insert(tag,getAtt("class"))
end
_stack:push("<"..table.concat(tag," ")..">")
io.write(_stack:join("").."\n")
-- io.write("Start "..t.."\n" )
end
obj.endtag = function(self,t,s,e)
_stack:pop()
-- io.write("End : "..t.."\n")
end
return obj
end
M.simpleTeXhandler = simpleTeXhandler
return M