instiki/vendor/plugins/HTML5lib/lib/html5lib/treebuilders/base.rb
Jacques Distler bd8ba1f4b1 REXML Trees
Synced with latest HTML5lib.
Added preliminary support (currently disabled) for sanitizing REXML trees.
2007-06-05 16:34:49 -05:00

331 lines
10 KiB
Ruby
Executable file

require 'html5lib/constants'
#XXX - TODO; make the default interface more ElementTree-like rather than DOM-like
module HTML5lib
# The scope markers are inserted when entering buttons, object elements,
# marquees, table cells, and table captions, and are used to prevent formatting
# from "leaking" into tables, buttons, object elements, and marquees.
Marker = nil
module TreeBuilders
module Base
class Node
# The parent of the current node (or nil for the document node)
attr_accessor :parent
# a list of child nodes of the current node. This must
# include all elements but not necessarily other node types
attr_accessor :childNodes
# A list of miscellaneous flags that can be set on the node
attr_accessor :_flags
def initialize(name)
@parent = nil
@childNodes = []
@_flags = []
end
# Insert node as a child of the current node
def appendChild(node)
raise NotImplementedError
end
# Insert data as text in the current node, positioned before the
# start of node insertBefore or to the end of the node's text.
def insertText(data, insertBefore=nil)
raise NotImplementedError
end
# Insert node as a child of the current node, before refNode in the
# list of child nodes. Raises ValueError if refNode is not a child of
# the current node
def insertBefore(node, refNode)
raise NotImplementedError
end
# Remove node from the children of the current node
def removeChild(node)
raise NotImplementedError
end
# Move all the children of the current node to newParent.
# This is needed so that trees that don't store text as nodes move the
# text in the correct way
def reparentChildren(newParent)
#XXX - should this method be made more general?
@childNodes.each { |child| newParent.appendChild(child) }
@childNodes = []
end
# Return a shallow copy of the current node i.e. a node with the same
# name and attributes but with no parent or child nodes
def cloneNode
raise NotImplementedError
end
# Return true if the node has children or text, false otherwise
def hasContent
raise NotImplementedError
end
end
# Base treebuilder implementation
class TreeBuilder
attr_accessor :openElements
attr_accessor :activeFormattingElements
attr_accessor :document
attr_accessor :headPointer
attr_accessor :formPointer
# Class to use for document root
documentClass = nil
# Class to use for HTML elements
elementClass = nil
# Class to use for comments
commentClass = nil
# Class to use for doctypes
doctypeClass = nil
# Fragment class
fragmentClass = nil
def initialize
reset
end
def reset
@openElements = []
@activeFormattingElements = []
#XXX - rename these to headElement, formElement
@headPointer = nil
@formPointer = nil
self.insertFromTable = false
@document = @documentClass.new
end
def elementInScope(target, tableVariant=false)
# Exit early when possible.
return true if @openElements[-1].name == target
# AT How about while true and simply set node to [-1] and set it to
# [-2] at the end...
@openElements.reverse.each do |element|
if element.name == target
return true
elsif element.name == 'table'
return false
elsif not tableVariant and SCOPING_ELEMENTS.include?(element.name)
return false
elsif element.name == 'html'
return false
end
end
assert false # We should never reach this point
end
def reconstructActiveFormattingElements
# Within this algorithm the order of steps described in the
# specification is not quite the same as the order of steps in the
# code. It should still do the same though.
# Step 1: stop the algorithm when there's nothing to do.
return if @activeFormattingElements.empty?
# Step 2 and step 3: we start with the last element. So i is -1.
i = -1
entry = @activeFormattingElements[i]
return if entry == Marker or @openElements.include?(entry)
# Step 6
until entry == Marker or @openElements.include?(entry)
# Step 5: let entry be one earlier in the list.
i -= 1
begin
entry = @activeFormattingElements[i]
rescue
# Step 4: at this point we need to jump to step 8. By not doing
# i += 1 which is also done in step 7 we achieve that.
break
end
end
while true
# Step 7
i += 1
# Step 8
clone = @activeFormattingElements[i].cloneNode
# Step 9
element = insertElement(clone.name, clone.attributes)
# Step 10
@activeFormattingElements[i] = element
# Step 11
break if element == @activeFormattingElements[-1]
end
end
def clearActiveFormattingElements
{} until @activeFormattingElements.empty? || @activeFormattingElements.pop == Marker
end
# Check if an element exists between the end of the active
# formatting elements and the last marker. If it does, return it, else
# return false
def elementInActiveFormattingElements(name)
@activeFormattingElements.reverse.each do |element|
# Check for Marker first because if it's a Marker it doesn't have a
# name attribute.
break if element == Marker
return element if element.name == name
end
return false
end
def insertDoctype(name)
@document.appendChild(@doctypeClass.new(name))
end
def insertComment(data, parent=nil)
parent = @openElements[-1] if parent.nil?
parent.appendChild(@commentClass.new(data))
end
# Create an element but don't insert it anywhere
def createElement(name, attributes)
element = @elementClass.new(name)
element.attributes = attributes
return element
end
# Switch the function used to insert an element from the
# normal one to the misnested table one and back again
def insertFromTable=(value)
@insertFromTable = value
@insertElement = value ? :insertElementTable : :insertElementNormal
end
def insertElement(name, attributes)
send(@insertElement, name, attributes)
end
def insertElementNormal(name, attributes)
element = @elementClass.new(name)
element.attributes = attributes
@openElements[-1].appendChild(element)
@openElements.push(element)
return element
end
# Create an element and insert it into the tree
def insertElementTable(name, attributes)
element = @elementClass.new(name)
element.attributes = attributes
if TABLE_INSERT_MODE_ELEMENTS.include?(@openElements[-1].name)
#We should be in the InTable mode. This means we want to do
#special magic element rearranging
parent, insertBefore = getTableMisnestedNodePosition
if insertBefore.nil?
parent.appendChild(element)
else
parent.insertBefore(element, insertBefore)
end
@openElements.push(element)
else
return insertElementNormal(name, attributes)
end
return element
end
def insertText(data, parent=nil)
parent = @openElements[-1] if parent.nil?
if (not(@insertFromTable) or (@insertFromTable and not TABLE_INSERT_MODE_ELEMENTS.include?(@openElements[-1].name)))
parent.insertText(data)
else
#We should be in the InTable mode. This means we want to do
#special magic element rearranging
parent, insertBefore = getTableMisnestedNodePosition
parent.insertText(data, insertBefore)
end
end
# Get the foster parent element, and sibling to insert before
# (or nil) when inserting a misnested table node
def getTableMisnestedNodePosition
#The foster parent element is the one which comes before the most
#recently opened table element
#XXX - this is really inelegant
lastTable = nil
fosterParent = nil
insertBefore = nil
@openElements.reverse.each do |element|
if element.name == "table"
lastTable = element
break
end
end
if lastTable
#XXX - we should really check that this parent is actually a
#node here
if lastTable.parent
fosterParent = lastTable.parent
insertBefore = lastTable
else
fosterParent = @openElements[@openElements.index(lastTable) - 1]
end
else
fosterParent = @openElements[0]
end
return fosterParent, insertBefore
end
def generateImpliedEndTags(exclude=nil)
name = @openElements[-1].name
if (['dd', 'dt', 'li', 'p', 'td', 'th', 'tr'].include?(name) and name != exclude)
@openElements.pop
# XXX This is not entirely what the specification says. We should
# investigate it more closely.
generateImpliedEndTags(exclude)
end
end
def getDocument
@document
end
def getFragment
#assert @innerHTML
fragment = @fragmentClass.new
@openElements[0].reparentChildren(fragment)
return fragment
end
# Serialize the subtree of node in the format required by unit tests
# node - the node from which to start serializing
def testSerializer(node)
raise NotImplementedError
end
end
end
end
end