class REXML::Document
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.
Constants
- DECLARATION
A convenient default XML declaration. Use:
mydoc << XMLDecl.default
Attributes
Public Class Methods
Get the entity expansion limit. By default the limit is set to 10000.
Deprecated. Use REXML::Security.entity_expansion_limit=
instead.
# File rexml-3.2.8/lib/rexml/document.rb, line 415 def Document::entity_expansion_limit return Security.entity_expansion_limit end
Set the entity expansion limit. By default the limit is set to 10000.
Deprecated. Use REXML::Security.entity_expansion_limit=
instead.
# File rexml-3.2.8/lib/rexml/document.rb, line 408 def Document::entity_expansion_limit=( val ) Security.entity_expansion_limit = val end
Get the entity expansion limit. By default the limit is set to 10240.
Deprecated. Use REXML::Security.entity_expansion_text_limit
instead.
# File rexml-3.2.8/lib/rexml/document.rb, line 429 def Document::entity_expansion_text_limit return Security.entity_expansion_text_limit end
Set the entity expansion limit. By default the limit is set to 10240.
Deprecated. Use REXML::Security.entity_expansion_text_limit=
instead.
# File rexml-3.2.8/lib/rexml/document.rb, line 422 def Document::entity_expansion_text_limit=( val ) Security.entity_expansion_text_limit = val end
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}
# File rexml-3.2.8/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
# File rexml-3.2.8/lib/rexml/document.rb, line 401 def Document::parse_stream( source, listener ) Parsers::StreamParser.new( source, listener ).parse end
Public Instance Methods
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/>"
# File rexml-3.2.8/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
Adds an element to the document by calling REXML::Element.add_element
:
REXML::Element.add_element(name_or_element, attributes)
# File rexml-3.2.8/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
Returns the new document resulting from executing Document.new(self)
. See Document.new
.
# File rexml-3.2.8/lib/rexml/document.rb, line 120 def clone Document.new self end
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
# File rexml-3.2.8/lib/rexml/document.rb, line 241 def doctype @children.find { |item| item.kind_of? DocType } end
# File rexml-3.2.8/lib/rexml/document.rb, line 442 def document self end
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"
# File rexml-3.2.8/lib/rexml/document.rb, line 290 def encoding xml_decl().encoding end
Returns an empty string.
# File rexml-3.2.8/lib/rexml/document.rb, line 129 def expanded_name '' #d = doc_type #d ? d.name : "UNDEFINED" end
Returns the symbol :document
.
# File rexml-3.2.8/lib/rexml/document.rb, line 110 def node_type :document end
# File rexml-3.2.8/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
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
# File rexml-3.2.8/lib/rexml/document.rb, line 225 def root elements[1] #self #@children.find { |item| item.kind_of? Element } end
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
# File rexml-3.2.8/lib/rexml/document.rb, line 305 def stand_alone? xml_decl().stand_alone? end
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"
# File rexml-3.2.8/lib/rexml/document.rb, line 275 def version xml_decl().version 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 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.
# File rexml-3.2.8/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
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 # => ""
# File rexml-3.2.8/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
Private Instance Methods
# File rexml-3.2.8/lib/rexml/document.rb, line 447 def build( source ) Parsers::TreeParser.new( source, self ).parse end