Class: REXML::Document

Class

REXML::Document

In:

lib/rexml/document.rb

Parent:

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|.

Methods

<< add add_element build clone doctype encoding expanded_name name new node_type parse_stream root stand_alone? version write xml_decl

Constants

DECLARATION = XMLDecl.default 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

Public Class methods

new( source = nil, context = {} )

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.

    # File lib/rexml/document.rb, line 34
34:                 def initialize( source = nil, context = {} )
35:                         super()
36:                         @context = context
37:                         return if source.nil?
38:                         if source.kind_of? Document
39:                                 @context = source.context
40:                                 super source
41:                         else
42:                                 build(  source )
43:                         end
44:                 end

parse_stream( source, listener )

     # File lib/rexml/document.rb, line 199
199:                 def Document::parse_stream( source, listener )
200:                         Parsers::StreamParser.new( source, listener ).parse
201:                 end

Public Instance methods

<<( child )

Alias for add

We override this, because XMLDecls and DocTypes must go at the start of the document

    # File lib/rexml/document.rb, line 66
66:                 def add( child )
67:                         if child.kind_of? XMLDecl
68:                                 @children.unshift child
69:         child.parent = self
70:                         elsif child.kind_of? DocType
71:         # Find first Element or DocType node and insert the decl right 
72:         # before it.  If there is no such node, just insert the child at the
73:         # end.  If there is a child and it is an DocType, then replace it.
74:         insert_before_index = 0
75:         @children.find { |x| 
76:           insert_before_index += 1
77:           x.kind_of?(Element) || x.kind_of?(DocType)
78:         }
79:         if @children[ insert_before_index ] # Not null = not end of list
80:           if @children[ insert_before_index ].kind_of DocType
81:             @children[ insert_before_index ] = child
82:           else
83:             @children[ index_before_index-1, 0 ] = child
84:           end
85:         else  # Insert at end of list
86:           @children[insert_before_index] = child
87:         end
88:                                 child.parent = self
89:                         else
90:                                 rv = super
91:                                 raise "attempted adding second root element to document" if @elements.size > 1
92:                                 rv
93:                         end
94:                 end

add_element(arg=nil, arg2=nil)

     # File lib/rexml/document.rb, line 97
 97:                 def add_element(arg=nil, arg2=nil)
 98:                         rv = super
 99:                         raise "attempted adding second root element to document" if @elements.size > 1
100:                         rv
101:                 end

Should be obvious

    # File lib/rexml/document.rb, line 51
51:                 def clone
52:                         Document.new self
53:                 end

@return the DocType child of the document, if one exists, and nil otherwise.

     # File lib/rexml/document.rb, line 113
113:                 def doctype
114:                         @children.find { |item| item.kind_of? DocType }
115:                 end

@return the XMLDecl encoding of this document as a String. If no XMLDecl has been set, returns the default encoding.

     # File lib/rexml/document.rb, line 133
133:                 def encoding
134:                         xml_decl().encoding
135:                 end

expanded_name()

According to the XML spec, a root node has no expanded name

    # File lib/rexml/document.rb, line 56
56:                 def expanded_name
57:                         ''
58:                         #d = doc_type
59:                         #d ? d.name : "UNDEFINED"
60:                 end

name()

Alias for expanded_name

    # File lib/rexml/document.rb, line 46
46:     def node_type
47:       :document
48:     end

@return the root Element of the document, or nil if this document has no children.

     # File lib/rexml/document.rb, line 105
105:                 def root
106:       elements[1]
107:       #self
108:       #@children.find { |item| item.kind_of? Element }
109:                 end

@return the XMLDecl standalone value of this document as a String. If no XMLDecl has been set, returns the default setting.

     # File lib/rexml/document.rb, line 139
139:                 def stand_alone?
140:                         xml_decl().stand_alone?
141:                 end

@return the XMLDecl version of this document as a String. If no XMLDecl has been set, returns the default version.

     # File lib/rexml/document.rb, line 127
127:                 def version
128:                         xml_decl().version
129:                 end

write( output=$stdout, indent=-1, trans=false, ie_hack=false )

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.

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

Examples

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

  output_string = ""
  tr = Transitive.new( output_string )
  Document.new("<a><b/></a>").serialize( tr )

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
trans:	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

     # File lib/rexml/document.rb, line 182
182:                 def write( output=$stdout, indent=-1, trans=false, ie_hack=false )
183:       if xml_decl.encoding != "UTF-8" && !output.kind_of?(Output)
184:         output = Output.new( output, xml_decl.encoding )
185:       end
186:       formatter = if indent > -1
187:           if trans
188:             REXML::Formatters::Transitive.new( indent, ie_hack )
189:           else
190:             REXML::Formatters::Pretty.new( indent, ie_hack )
191:           end
192:         else
193:           REXML::Formatters::Default.new( ie_hack )
194:         end
195:       formatter.write( self, output )
196:                 end

@return the XMLDecl of this document; if no XMLDecl has been set, the default declaration is returned.

     # File lib/rexml/document.rb, line 119
119:                 def xml_decl
120:                         rv = @children[0]
121:       return rv if rv.kind_of? XMLDecl
122:       rv = @children.unshift(XMLDecl.default)[0]
123:                 end

Private Instance methods

build( source )

     # File lib/rexml/document.rb, line 204
204:                 def build( source )
205:       Parsers::TreeParser.new( source, self ).parse
206:                 end