Element
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|.
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
Get the entity expansion limit. By default the limit is set to 10000.
# File rexml/document.rb, line 215
def Document::entity_expansion_limit
return @@entity_expansion_limit
end
Set the entity expansion limit. By default the limit is set to 10000.
# File rexml/document.rb, line 210
def Document::entity_expansion_limit=( val )
@@entity_expansion_limit = val
end
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 rexml/document.rb, line 34
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
We override this, because XMLDecls and DocTypes must go at the start of the document
# File rexml/document.rb, line 67
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
# File rexml/document.rb, line 100
def add_element(arg=nil, arg2=nil)
rv = super
raise "attempted adding second root element to document" if @elements.size > 1
rv
end
Should be obvious
# File rexml/document.rb, line 52
def clone
Document.new self
end
@return the DocType child of the document, if one exists, and nil otherwise.
# File rexml/document.rb, line 116
def doctype
@children.find { |item| item.kind_of? DocType }
end
According to the XML spec, a root node has no expanded name
# File rexml/document.rb, line 57
def expanded_name
''
#d = doc_type
#d ? d.name : "UNDEFINED"
end
# File rexml/document.rb, line 221
def record_entity_expansion
@entity_expansion_count += 1
if @entity_expansion_count > @@entity_expansion_limit
raise "number of entity expansions exceeded, processing aborted."
end
end
@return the root Element of the document, or nil if this document has no children.
# File rexml/document.rb, line 108
def root
elements[1]
#self
#@children.find { |item| item.kind_of? Element }
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.
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 |
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 |
# File rexml/document.rb, line 185
def write( output=$stdout, indent=-1, transitive=false, ie_hack=false )
if xml_decl.encoding != "UTF-8" && !output.kind_of?(Output)
output = Output.new( output, xml_decl.encoding )
end
formatter = if indent > -1
if transitive
require "rexml/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