ruby/lib/rexml/document.rb

244 строки
7.6 KiB
Ruby

require "rexml/element"
require "rexml/xmldecl"
require "rexml/source"
require "rexml/comment"
require "rexml/doctype"
require "rexml/instruction"
require "rexml/rexml"
require "rexml/parseexception"
require "rexml/output"
require "rexml/parsers/baseparser"
require "rexml/parsers/streamparser"
module REXML
# Represents a full XML document, including PIs, a doctype, etc. A
# Document has a single child that can be accessed by root().
# Note that if you want to have an XML declaration written for a document
# you create, you must add one; REXML documents do not write a default
# declaration for you. See |DECLARATION| and |write|.
class Document < Element
# A convenient default XML declaration. If you want an XML declaration,
# the easiest way to add one is mydoc << Document::DECLARATION
# +DEPRECATED+
# Use: mydoc << XMLDecl.default
DECLARATION = XMLDecl.default
# Constructor
# @param source if supplied, must be a Document, String, or IO.
# Documents have their context and Element attributes cloned.
# Strings are expected to be valid XML documents. IOs are expected
# to be sources of valid XML documents.
# @param context if supplied, contains the context of the document;
# this should be a Hash.
# NOTE that I'm not sure what the context is for; I cloned it out of
# the Electric XML API (in which it also seems to do nothing), and it
# is now legacy. It may do something, someday... it may disappear.
def initialize( source = nil, context = {} )
super()
@context = context
return if source.nil?
if source.kind_of? Document
@context = source.context
super source
else
build( source )
end
end
def node_type
:document
end
# Should be obvious
def clone
Document.new self
end
# According to the XML spec, a root node has no expanded name
def expanded_name
''
#d = doc_type
#d ? d.name : "UNDEFINED"
end
alias :name :expanded_name
# We override this, because XMLDecls and DocTypes must go at the start
# of the document
def add( child )
if child.kind_of? XMLDecl
@children.unshift child
elsif child.kind_of? DocType
if @children[0].kind_of? XMLDecl
@children[1,0] = child
else
@children.unshift child
end
child.parent = self
else
rv = super
raise "attempted adding second root element to document" if @elements.size > 1
rv
end
end
alias :<< :add
def add_element(arg=nil, arg2=nil)
rv = super
raise "attempted adding second root element to document" if @elements.size > 1
rv
end
# @return the root Element of the document, or nil if this document
# has no children.
def root
@children.find { |item| item.kind_of? Element }
end
# @return the DocType child of the document, if one exists,
# and nil otherwise.
def doctype
@children.find { |item| item.kind_of? DocType }
end
# @return the XMLDecl of this document; if no XMLDecl has been
# set, the default declaration is returned.
def xml_decl
rv = @children[0]
return rv if rv.kind_of? XMLDecl
rv = @children.unshift(XMLDecl.default)[0]
end
# @return the XMLDecl version of this document as a String.
# If no XMLDecl has been set, returns the default version.
def version
xml_decl().version
end
# @return the XMLDecl encoding of this document as a String.
# If no XMLDecl has been set, returns the default encoding.
def encoding
xml_decl().encoding
end
# @return the XMLDecl standalone value of this document as a String.
# If no XMLDecl has been set, returns the default setting.
def stand_alone?
xml_decl().stand_alone?
end
# Write the XML tree out, optionally with indent. This writes out the
# entire XML document, including XML declarations, doctype declarations,
# and processing instructions (if any are given).
# A controversial point is whether Document should always write the XML
# declaration (<?xml version='1.0'?>) whether or not one is given by the
# user (or source document). REXML does not write one if one was not
# specified, because it adds unneccessary bandwidth to applications such
# as XML-RPC.
#
#
# output::
# output an object which supports '<< string'; this is where the
# document will be written.
# indent::
# An integer. If -1, no indenting will be used; otherwise, the
# indentation will be this number of spaces, and children will be
# indented an additional amount. Defaults to -1
# transitive::
# If transitive is true and indent is >= 0, then the output will be
# pretty-printed in such a way that the added whitespace does not affect
# the absolute *value* of the document -- that is, it leaves the value
# and number of Text nodes in the document unchanged.
# ie_hack::
# Internet Explorer is the worst piece of crap to have ever been
# written, with the possible exception of Windows itself. Since IE is
# unable to parse proper XML, we have to provide a hack to generate XML
# that IE's limited abilities can handle. This hack inserts a space
# before the /> on empty tags. Defaults to false
def write( output=$stdout, indent=-1, transitive=false, ie_hack=false )
output = Output.new( output, xml_decl.encoding ) if xml_decl.encoding != "UTF-8" && !output.kind_of?(Output)
@children.each { |node|
indent( output, indent) if node.node_type == :element
node.write( output, indent, transitive, ie_hack )
output << "\n" unless indent<0 or node == @children[-1]
}
end
def Document::parse_stream( source, listener )
Parsers::StreamParser.new( source, listener ).parse
end
private
def build( source )
build_context = self
parser = Parsers::BaseParser.new( source )
tag_stack = []
in_doctype = false
entities = nil
while true
event = parser.pull
case event[0]
when :end_document
return
when :start_element
tag_stack.push(event[1])
# find the observers for namespaces
build_context = build_context.add_element( event[1], event[2] )
when :end_element
tag_stack.pop
build_context = build_context.parent
when :text
if not in_doctype
if build_context[-1].instance_of? Text
build_context[-1] << event[1]
else
build_context.add(
Text.new( event[1], build_context.whitespace, nil, true )
) unless (
event[1].strip.size==0 and
build_context.ignore_whitespace_nodes
)
end
end
when :comment
c = Comment.new( event[1] )
build_context.add( c )
when :cdata
c = CData.new( event[1] )
build_context.add( c )
when :processing_instruction
build_context.add( Instruction.new( event[1], event[2] ) )
when :end_doctype
in_doctype = false
entities.each { |k,v| entities[k] = build_context.entities[k].value }
build_context = build_context.parent
when :start_doctype
doctype = DocType.new( event[1..-1], build_context )
build_context = doctype
entities = {}
in_doctype = true
when :attlistdecl
n = AttlistDecl.new( event[1..-1] )
build_context.add( n )
when :externalentity
n = ExternalEntity.new( event[1] )
build_context.add( n )
when :elementdecl
n = ElementDecl.new( event[1] )
build_context.add(n)
when :entitydecl
entities[ event[1] ] = event[2] unless event[2] =~ /PUBLIC|SYSTEM/
build_context.add(Entity.new(event))
when :notationdecl
n = NotationDecl.new( *event[1..-1] )
build_context.add( n )
when :xmldecl
x = XMLDecl.new( event[1], event[2], event[3] )
build_context.add( x )
end
end
end
end
end