Class: REXML::Document

Inherits:
Element show all
Defined in:
lib/rexml/document.rb

Overview

Represents an XML document.

A document may have:

  • A single child that may be accessed via method #root.

  • An XML declaration.

  • A document type.

  • Processing instructions.

In a Hurry?

If you’re somewhat familiar with XML and have a particular task in mind, you may want to see the tasks pages, and in particular, the tasks page for documents.

Constant Summary collapse

DECLARATION =

A convenient default XML declaration. Use:

mydoc << XMLDecl.default

XMLDecl.default

Constants inherited from Element

Element::UNDEFINED

Constants included from Namespace

Namespace::NAMESPLIT, Namespace::NAME_WITHOUT_NAMESPACE

Constants included from XMLTokens

XMLTokens::NAME, XMLTokens::NAMECHAR, XMLTokens::NAME_CHAR, XMLTokens::NAME_START_CHAR, XMLTokens::NAME_STR, XMLTokens::NCNAME_STR, XMLTokens::NMTOKEN, XMLTokens::NMTOKENS, XMLTokens::REFERENCE

Instance Attribute Summary collapse

Attributes inherited from Element

#attributes, #context, #elements

Attributes included from Namespace

#prefix

Attributes inherited from Child

#parent

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Element

#[], #add_attribute, #add_attributes, #add_namespace, #add_text, #attribute, #cdatas, #comments, #delete_attribute, #delete_element, #delete_namespace, #each_element, #each_element_with_attribute, #each_element_with_text, #get_elements, #get_text, #has_attributes?, #has_elements?, #has_text?, #ignore_whitespace_nodes, #inspect, #instructions, #namespace, #namespaces, #next_element, #prefixes, #previous_element, #raw, #root_node, #text, #text=, #texts, #whitespace, #xpath

Methods included from Namespace

#fully_expanded_name, #has_name?

Methods inherited from Parent

#[], #[]=, #deep_clone, #delete, #delete_at, #delete_if, #each, #each_index, #index, #insert_after, #insert_before, #parent?, #replace_child, #size, #to_a, #unshift

Methods inherited from Child

#bytes, #next_sibling=, #previous_sibling=, #remove, #replace_with

Methods included from Node

#each_recursive, #find_first_recursive, #indent, #index_in_parent, #next_sibling_node, #parent?, #previous_sibling_node, #to_s

Constructor Details

#initialize(source = nil, context = {}) ⇒ Document

:call-seq:

new(string = nil, context = {}) -> new_document
new(io_stream = nil, context = {}) -> new_document
new(document = nil, context = {}) -> new_document

Returns a new REXML::Document object.

When no arguments are given, returns an empty document:

d = REXML::Document.new
d.to_s # => ""

When argument string is given, it must be a string containing a valid XML document:

xml_string = '<root><foo>Foo</foo><bar>Bar</bar></root>'
d = REXML::Document.new(xml_string)
d.to_s # => "<root><foo>Foo</foo><bar>Bar</bar></root>"

When argument io_stream is given, it must be an IO object that is opened for reading, and when read must return a valid XML document:

File.write('t.xml', xml_string)
d = File.open('t.xml', 'r') do |io|
  REXML::Document.new(io)
end
d.to_s # => "<root><foo>Foo</foo><bar>Bar</bar></root>"

When argument document is given, it must be an existing document object, whose context and attributes (but not children) are cloned into the new document:

d = REXML::Document.new(xml_string)
d.children    # => [<root> ... </>]
d.context = {raw: :all, compress_whitespace: :all}
d.add_attributes({'bar' => 0, 'baz' => 1})
d1 = REXML::Document.new(d)
d1.children   # => []
d1.context    # => {:raw=>:all, :compress_whitespace=>:all}
d1.attributes # => {"bar"=>bar='0', "baz"=>baz='1'}

When argument context is given, it must be a hash containing context entries for the document; see Element Context:

context = {raw: :all, compress_whitespace: :all}
d = REXML::Document.new(xml_string, context)
d.context # => {:raw=>:all, :compress_whitespace=>:all}



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# File 'lib/rexml/document.rb', line 92

def initialize( source = nil, context = {} )
  @entity_expansion_count = 0
  super()
  @context = context
  return if source.nil?
  if source.kind_of? Document
    @context = source.context
    super source
  else
    build(  source )
  end
end

Instance Attribute Details

#entity_expansion_count ⇒ Object (readonly)

Returns the value of attribute entity_expansion_count.



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# File 'lib/rexml/document.rb', line 433

def entity_expansion_count
  @entity_expansion_count
end

Class Method Details

.entity_expansion_limit ⇒ Object

Get the entity expansion limit. By default the limit is set to 10000.

Deprecated. Use REXML::Security.entity_expansion_limit= instead.



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# File 'lib/rexml/document.rb', line 415

def Document::entity_expansion_limit
  return Security.entity_expansion_limit
end

.entity_expansion_limit=(val) ⇒ Object

Set the entity expansion limit. By default the limit is set to 10000.

Deprecated. Use REXML::Security.entity_expansion_limit= instead.



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# File 'lib/rexml/document.rb', line 408

def Document::entity_expansion_limit=( val )
  Security.entity_expansion_limit = val
end

.entity_expansion_text_limit ⇒ Object

Get the entity expansion limit. By default the limit is set to 10240.

Deprecated. Use REXML::Security.entity_expansion_text_limit instead.



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# File 'lib/rexml/document.rb', line 429

def Document::entity_expansion_text_limit
  return Security.entity_expansion_text_limit
end

.entity_expansion_text_limit=(val) ⇒ Object

Set the entity expansion limit. By default the limit is set to 10240.

Deprecated. Use REXML::Security.entity_expansion_text_limit= instead.



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# File 'lib/rexml/document.rb', line 422

def Document::entity_expansion_text_limit=( val )
  Security.entity_expansion_text_limit = val
end

.parse_stream(source, listener) ⇒ Object 



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# File 'lib/rexml/document.rb', line 401

def Document::parse_stream( source, listener )
  Parsers::StreamParser.new( source, listener ).parse
end

Instance Method Details

#add(child) ⇒ Object Also known as: <<

:call-seq:

add(xml_decl) -> self
add(doc_type) -> self
add(object) -> self

Adds an object to the document; returns self.

When argument xml_decl is given, it must be an REXML::XMLDecl object, which becomes the XML declaration for the document, replacing the previous XML declaration if any:

d = REXML::Document.new
d.xml_decl.to_s # => ""
d.add(REXML::XMLDecl.new('2.0'))
d.xml_decl.to_s # => "<?xml version='2.0'?>"

When argument doc_type is given, it must be an REXML::DocType object, which becomes the document type for the document, replacing the previous document type, if any:

d = REXML::Document.new
d.doctype.to_s # => ""
d.add(REXML::DocType.new('foo'))
d.doctype.to_s # => "<!DOCTYPE foo>"

When argument object (not an REXML::XMLDecl or REXML::DocType object) is given it is added as the last child:

d = REXML::Document.new
d.add(REXML::Element.new('foo'))
d.to_s # => "<foo/>"



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# File 'lib/rexml/document.rb', line 170

def add( child )
  if child.kind_of? XMLDecl
    if @children[0].kind_of? XMLDecl
      @children[0] = child
    else
      @children.unshift child
    end
    child.parent = self
  elsif child.kind_of? DocType
    # Find first Element or DocType node and insert the decl right
    # before it.  If there is no such node, just insert the child at the
    # end.  If there is a child and it is an DocType, then replace it.
    insert_before_index = @children.find_index { |x|
      x.kind_of?(Element) || x.kind_of?(DocType)
    }
    if insert_before_index # Not null = not end of list
      if @children[ insert_before_index ].kind_of? DocType
        @children[ insert_before_index ] = child
      else
        @children[ insert_before_index-1, 0 ] = child
      end
    else  # Insert at end of list
      @children << child
    end
    child.parent = self
  else
    rv = super
    raise "attempted adding second root element to document" if @elements.size > 1
    rv
  end
end

#add_element(arg = nil, arg2 = nil) ⇒ Object

:call-seq:

add_element(name_or_element = nil, attributes = nil) -> new_element

Adds an element to the document by calling REXML::Element.add_element:

REXML::Element.add_element(name_or_element, attributes)



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# File 'lib/rexml/document.rb', line 209

def add_element(arg=nil, arg2=nil)
  rv = super
  raise "attempted adding second root element to document" if @elements.size > 1
  rv
end

#clone ⇒ Object

:call-seq:

clone -> new_document

Returns the new document resulting from executing Document.new(self). See Document.new.



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# File 'lib/rexml/document.rb', line 120

def clone
  Document.new self
end

#doctype ⇒ Object

:call-seq:

doctype -> doc_type or nil

Returns the DocType object for the document, if it exists, otherwise nil:

d = REXML::Document.new('<!DOCTYPE document SYSTEM "subjects.dtd">')
d.doctype.class # => REXML::DocType
d = REXML::Document.new('')
d.doctype.class # => nil



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# File 'lib/rexml/document.rb', line 241

def doctype
  @children.find { |item| item.kind_of? DocType }
end

#document ⇒ Object 



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# File 'lib/rexml/document.rb', line 442

def document
  self
end

#encoding ⇒ Object

:call-seq:

encoding -> encoding_string

Returns the XMLDecl encoding of the document, if it has been set, otherwise the default encoding:

d = REXML::Document.new('<?xml version="1.0" encoding="UTF-16"?>')
d.encoding # => "UTF-16"
d = REXML::Document.new('')
d.encoding # => "UTF-8"



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# File 'lib/rexml/document.rb', line 290

def encoding
  xml_decl().encoding
end

#expanded_name ⇒ Object Also known as: name

:call-seq:

expanded_name -> empty_string

Returns an empty string.



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# File 'lib/rexml/document.rb', line 129

def expanded_name
  ''
  #d = doc_type
  #d ? d.name : "UNDEFINED"
end

#node_type ⇒ Object

:call-seq:

node_type -> :document

Returns the symbol :document.



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# File 'lib/rexml/document.rb', line 110

def node_type
  :document
end

#record_entity_expansion ⇒ Object 



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# File 'lib/rexml/document.rb', line 435

def record_entity_expansion
  @entity_expansion_count += 1
  if @entity_expansion_count > Security.entity_expansion_limit
    raise "number of entity expansions exceeded, processing aborted."
  end
end

#root ⇒ Object

:call-seq:

root -> root_element or nil

Returns the root element of the document, if it exists, otherwise nil:

d = REXML::Document.new('<root></root>')
d.root # => <root/>
d = REXML::Document.new('')
d.root # => nil



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# File 'lib/rexml/document.rb', line 225

def root
  elements[1]
  #self
  #@children.find { |item| item.kind_of? Element }
end

#stand_alone? ⇒ Boolean

:call-seq:

stand_alone?

Returns the XMLDecl standalone value of the document as a string, if it has been set, otherwise the default standalone value:

d = REXML::Document.new('<?xml standalone="yes"?>')
d.stand_alone? # => "yes"
d = REXML::Document.new('')
d.stand_alone? # => nil

Returns:

  • (Boolean) 


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# File 'lib/rexml/document.rb', line 305

def stand_alone?
  xml_decl().stand_alone?
end

#version ⇒ Object

:call-seq:

version -> version_string

Returns the XMLDecl version of this document as a string, if it has been set, otherwise the default version:

d = REXML::Document.new('<?xml version="2.0" encoding="UTF-8"?>')
d.version # => "2.0"
d = REXML::Document.new('')
d.version # => "1.0"



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# File 'lib/rexml/document.rb', line 275

def version
  xml_decl().version
end

#write(*arguments) ⇒ Object

:call-seq:

doc.write(output=$stdout, indent=-1, transtive=false, ie_hack=false, encoding=nil)
doc.write(options={:output => $stdout, :indent => -1, :transtive => false, :ie_hack => false, :encoding => nil})

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 unnecessary bandwidth to applications such as XML-RPC.

Accept Nth argument style and options Hash style as argument. The recommended style is options Hash style for one or more arguments case.

Examples

Document.new("<a><b/></a>").write

output = ""
Document.new("<a><b/></a>").write(output)

output = ""
Document.new("<a><b/></a>").write(:output => output, :indent => 2)

See also the classes in the rexml/formatters package for the proper way to change the default formatting of XML output.

Examples

output = ""
tr = Transitive.new
tr.write(Document.new("<a><b/></a>"), output)
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 twice this number of spaces, and children will be indented an additional amount. For a value of 3, every item will be indented 3 more levels, or 6 more spaces (2 * 3). 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

This hack inserts a space before the /> on empty tags to address a limitation of Internet Explorer. Defaults to false

encoding

Encoding name as String. Change output encoding to specified encoding instead of encoding in XML declaration. Defaults to nil. It means encoding in XML declaration is used.



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# File 'lib/rexml/document.rb', line 365

def write(*arguments)
  if arguments.size == 1 and arguments[0].class == Hash
    options = arguments[0]

    output     = options[:output]
    indent     = options[:indent]
    transitive = options[:transitive]
    ie_hack    = options[:ie_hack]
    encoding   = options[:encoding]
  else
    output, indent, transitive, ie_hack, encoding, = *arguments
  end

  output   ||= $stdout
  indent   ||= -1
  transitive = false if transitive.nil?
  ie_hack    = false if ie_hack.nil?
  encoding ||= xml_decl.encoding

  if encoding != 'UTF-8' && !output.kind_of?(Output)
    output = Output.new( output, encoding )
  end
  formatter = if indent > -1
      if transitive
        require_relative "formatters/transitive"
        REXML::Formatters::Transitive.new( indent, ie_hack )
      else
        REXML::Formatters::Pretty.new( indent, ie_hack )
      end
    else
      REXML::Formatters::Default.new( ie_hack )
    end
  formatter.write( self, output )
end

#xml_decl ⇒ Object

:call-seq:

xml_decl -> xml_decl

Returns the XMLDecl object for the document, if it exists, otherwise the default XMLDecl object:

d = REXML::Document.new('<?xml version="1.0" encoding="UTF-8"?>')
d.xml_decl.class # => REXML::XMLDecl
d.xml_decl.to_s  # => "<?xml version='1.0' encoding='UTF-8'?>"
d = REXML::Document.new('')
d.xml_decl.class # => REXML::XMLDecl
d.xml_decl.to_s  # => ""



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# File 'lib/rexml/document.rb', line 258

def xml_decl
  rv = @children[0]
  return rv if rv.kind_of? XMLDecl
  @children.unshift(XMLDecl.default)[0]
end