Class: REXML::Attribute (Ruby 2.3.4)

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  • rexml/attribute.rb

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REXML::Attribute

Defines an Element Attribute; IE, a attribute=value pair, as in: <element attribute=“value”/>. Attributes can be in their own namespaces. General users of REXML will not interact with the Attribute class much.

Attributes

element[R]

The element to which this attribute belongs

normalized[W]

The normalized value of this attribute. That is, the attribute with entities intact.

Public Class Methods

new( first, second=nil, parent=nil )

Constructor. FIXME: The parser doesn’t catch illegal characters in attributes

first

Either: an Attribute, which this new attribute will become a clone of; or a String, which is the name of this attribute

second

If first is an Attribute, then this may be an Element, or nil. If nil, then the Element parent of this attribute is the parent of the first Attribute. If the first argument is a String, then this must also be a String, and is the content of the attribute. If this is the content, it must be fully normalized (contain no illegal characters).

parent

Ignored unless first is a String; otherwise, may be the Element parent of this attribute, or nil.

Attribute.new( attribute_to_clone )
Attribute.new( attribute_to_clone, parent_element )
Attribute.new( "attr", "attr_value" )
Attribute.new( "attr", "attr_value", parent_element )

 
               # File rexml/attribute.rb, line 45
def initialize( first, second=nil, parent=nil )
  @normalized = @unnormalized = @element = nil
  if first.kind_of? Attribute
    self.name = first.expanded_name
    @unnormalized = first.value
    if second.kind_of? Element
      @element = second
    else
      @element = first.element
    end
  elsif first.kind_of? String
    @element = parent
    self.name = first
    @normalized = second.to_s
  else
    raise "illegal argument #{first.class.name} to Attribute constructor"
  end
end

Public Instance Methods

==( other )

Returns true if other is an Attribute and has the same name and value, false otherwise.

 
               # File rexml/attribute.rb, line 96
def ==( other )
  other.kind_of?(Attribute) and other.name==name and other.value==value
end
clone()

Returns a copy of this attribute

 
               # File rexml/attribute.rb, line 145
def clone
  Attribute.new self
end
doctype() 
 
               # File rexml/attribute.rb, line 119
def doctype
  if @element
    doc = @element.document
    doc.doctype if doc
  end
end
element=( element )

Sets the element of which this object is an attribute. Normally, this is not directly called.

Returns this attribute

 
               # File rexml/attribute.rb, line 153
def element=( element )
  @element = element

  if @normalized
    Text.check( @normalized, NEEDS_A_SECOND_CHECK, doctype )
  end

  self
end
hash()

Creates (and returns) a hash from both the name and value

 
               # File rexml/attribute.rb, line 101
def hash
  name.hash + value.hash
end
inspect() 
 
               # File rexml/attribute.rb, line 179
def inspect
  rv = ""
  write( rv )
  rv
end
namespace(arg=nil)

Returns the namespace URL, if defined, or nil otherwise

e = Element.new("el")
e.add_namespace("ns", "http://url")
e.add_attribute("ns:a", "b")
e.add_attribute("nsx:a", "c")
e.attribute("ns:a").namespace # => "http://url"
e.attribute("nsx:a").namespace # => nil

 
               # File rexml/attribute.rb, line 89
def namespace arg=nil
  arg = prefix if arg.nil?
  @element.namespace arg
end
node_type() 
 
               # File rexml/attribute.rb, line 175
def node_type
  :attribute
end
prefix()

Returns the namespace of the attribute.

e = Element.new( "elns:myelement" )
e.add_attribute( "nsa:a", "aval" )
e.add_attribute( "b", "bval" )
e.attributes.get_attribute( "a" ).prefix   # -> "nsa"
e.attributes.get_attribute( "b" ).prefix   # -> "elns"
a = Attribute.new( "x", "y" )
a.prefix                                   # -> ""

 
               # File rexml/attribute.rb, line 73
def prefix
  pf = super
  if pf == ""
    pf = @element.prefix if @element
  end
  pf
end
remove()

Removes this Attribute from the tree, and returns true if successful

This method is usually not called directly.

 
               # File rexml/attribute.rb, line 166
def remove
  @element.attributes.delete self.name unless @element.nil?
end
to_s()

Returns the attribute value, with entities replaced

 
               # File rexml/attribute.rb, line 127
def to_s
  return @normalized if @normalized

  @normalized = Text::normalize( @unnormalized, doctype )
  @unnormalized = nil
  @normalized
end
to_string()

Returns this attribute out as XML source, expanding the name

a = Attribute.new( "x", "y" )
a.to_string     # -> "x='y'"
b = Attribute.new( "ns:x", "y" )
b.to_string     # -> "ns:x='y'"

 
               # File rexml/attribute.rb, line 111
def to_string
  if @element and @element.context and @element.context[:attribute_quote] == :quote
    %Q^#@expanded_name="#{to_s().gsub(/"/, '&quot;')}"^
  else
    "#@expanded_name='#{to_s().gsub(/'/, '&apos;')}'"
  end
end
value()

Returns the UNNORMALIZED value of this attribute. That is, entities have been expanded to their values

 
               # File rexml/attribute.rb, line 137
def value
  return @unnormalized if @unnormalized
  @unnormalized = Text::unnormalize( @normalized, doctype )
  @normalized = nil
  @unnormalized
end
write( output, indent=-1 )

Writes this attribute (EG, puts ‘key=“value”’ to the output)

 
               # File rexml/attribute.rb, line 171
def write( output, indent=-1 )
  output << to_string
end
xpath() 
 
               # File rexml/attribute.rb, line 185
def xpath
  path = @element.xpath
  path += "/@#{self.expanded_name}"
  return path
end