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.
Constructor. FIXME: The parser doesn't catch illegal characters in attributes
Either: an Attribute, which this new attribute will become a clone of; or a String, which is the name of this attribute
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).
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
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
Returns a copy of this attribute
# File rexml/attribute.rb, line 145
def clone
Attribute.new self
end
# File rexml/attribute.rb, line 119
def doctype
if @element
doc = @element.document
doc.doctype if doc
end
end
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
Creates (and returns) a hash from both the name and value
# File rexml/attribute.rb, line 101
def hash
name.hash + value.hash
end
# File rexml/attribute.rb, line 179
def inspect
rv = ""
write( rv )
rv
end
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
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
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
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
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(/"/, '"')}"^
else
"#@expanded_name='#{to_s().gsub(/'/, ''')}'"
end
end
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