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.
The element to which this attribute belongs
The normalized value of this attribute. That is, the attribute with entities intact.
# File tmp/rubies/ruby-2.7.6/lib/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
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 aString, which is the name of this attribute - second
-
If
firstis anAttribute, then this may be anElement, or nil. If nil, then theElementparent of this attribute is the parent of thefirstAttribute. If the first argument is aString, then this must also be aString, and is the content of the attribute. If this is the content, it must be fully normalized (contain no illegal characters). - parent
-
Ignored unless
firstis aString; otherwise, may be theElementparent 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 tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 109
def ==( other )
other.kind_of?(Attribute) and other.name==name and other.value==value
end
Returns true if other is an Attribute and has the same name and value, false otherwise.
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 158
def clone
Attribute.new self
end
Returns a copy of this attribute
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 132
def doctype
if @element
doc = @element.document
doc.doctype if doc
end
end
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 166
def element=( element )
@element = element
if @normalized
Text.check( @normalized, NEEDS_A_SECOND_CHECK, doctype )
end
self
end
Sets the element of which this object is an attribute. Normally, this is not directly called.
Returns this attribute
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 114
def hash
name.hash + value.hash
end
Creates (and returns) a hash from both the name and value
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 192
def inspect
rv = ""
write( rv )
rv
end
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 98
def namespace arg=nil
arg = prefix if arg.nil?
if arg == ""
""
else
@element.namespace(arg)
end
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
This method always returns “” for no namespace attribute. Because the default namespace doesn’t apply to attribute names.
From www.w3.org/TR/xml-names/#uniqAttrs
> the default namespace does not apply to attribute names
e = REXML::Element.new("el") e.add_namespace("", "http://example.com/") e.namespace # => "http://example.com/" e.add_attribute("a", "b") e.attribute("a").namespace # => ""
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 188
def node_type
:attribute
end
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 73
def prefix
super
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 # -> "" a = Attribute.new( "x", "y" ) a.prefix # -> ""
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 179
def remove
@element.attributes.delete self.name unless @element.nil?
end
Removes this Attribute from the tree, and returns true if successful
This method is usually not called directly.
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 140
def to_s
return @normalized if @normalized
@normalized = Text::normalize( @unnormalized, doctype )
@unnormalized = nil
@normalized
end
Returns the attribute value, with entities replaced
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 124
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 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 tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 150
def value
return @unnormalized if @unnormalized
@unnormalized = Text::unnormalize( @normalized, doctype )
@normalized = nil
@unnormalized
end
Returns the UNNORMALIZED value of this attribute. That is, entities have been expanded to their values
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 184
def write( output, indent=-1 )
output << to_string
end
Writes this attribute (EG, puts ‘key=“value”’ to the output)
# File tmp/rubies/ruby-2.7.6/lib/rexml/attribute.rb, line 198
def xpath
path = @element.xpath
path += "/@#{self.expanded_name}"
return path
end