Class: REXML::Element

new( arg = UNDEFINED, parent=nil, context=nil )

Constructor

arg:	if not supplied, will be set to the default value. If a String, the name of this object will be set to the argument. If an Element, the object will be shallowly cloned; name, attributes, and namespaces will be copied. Children will `not` be copied.
parent:	if supplied, must be a Parent, and will be used as the parent of this object.
context:	If supplied, must be a hash containing context items. Context items include:

:respect_whitespace the value of this is :all or an array of strings being the names of the elements to respect whitespace for. Defaults to :all.
:compress_whitespace the value can be :all or an array of strings being the names of the elements to ignore whitespace on. Overrides :respect_whitespace.
:ignore_whitespace_nodes the value can be :all or an array of strings being the names of the elements in which to ignore whitespace-only nodes. If this is set, Text nodes which contain only whitespace will not be added to the document tree.
:raw can be :all, or an array of strings being the names of the elements to process in raw mode. In raw mode, special characters in text is not converted to or from entities.

[Source]

# File rexml/element.rb, line 58
    def initialize( arg = UNDEFINED, parent=nil, context=nil )
      super(parent)

      @elements = Elements.new(self)
      @attributes = Attributes.new(self)
      @context = context

      if arg.kind_of? String
        self.name = arg
      elsif arg.kind_of? Element
        self.name = arg.expanded_name
        arg.attributes.each_attribute{ |attribute|
          @attributes << Attribute.new( attribute )
        }
        @context = arg.context
      end
    end

add_attribute( key, value=nil )

Adds an attribute to this element, overwriting any existing attribute by the same name.

key:	can be either an Attribute or a String. If an Attribute, the attribute is added to the list of Element attributes. If String, the argument is used as the name of the new attribute, and the value parameter must be supplied.
value:	Required if `key` is a String, and ignored if the first argument is an Attribute. This is a String, and is used as the value of the new Attribute. This should be the unnormalized value of the attribute (without entities).
Returns:	the Attribute added

 e = Element.new 'e'
 e.add_attribute( 'a', 'b' )               #-> <e a='b'/>
 e.add_attribute( 'x:a', 'c' )             #-> <e a='b' x:a='c'/>
 e.add_attribute Attribute.new('b', 'd')   #-> <e a='b' x:a='c' b='d'/>

[Source]

# File rexml/element.rb, line 583
    def add_attribute( key, value=nil )
      if key.kind_of? Attribute
        @attributes << key
      else
        @attributes[key] = value
      end
    end

add_attributes(hash)

Add multiple attributes to this element.

hash:

is either a hash, or array of arrays

 el.add_attributes( {"name1"=>"value1", "name2"=>"value2"} )
 el.add_attributes( [ ["name1","value1"], ["name2"=>"value2"] ] )

[Source]

# File rexml/element.rb, line 595
    def add_attributes hash
      if hash.kind_of? Hash
        hash.each_pair {|key, value| @attributes[key] = value }
      elsif hash.kind_of? Array
        hash.each { |value| @attributes[ value[0] ] = value[1] }
      end
    end

add_element(element, attrs=nil)

Adds a child to this element, optionally setting attributes in the element.

element:	optional. If Element, the element is added. Otherwise, a new Element is constructed with the argument (see Element.initialize).
attrs:	If supplied, must be a Hash containing String name,value pairs, which will be used to set the attributes of the new Element.
Returns:	the Element that was added

 el = doc.add_element 'my-tag'
 el = doc.add_element 'my-tag', {'attr1'=>'val1', 'attr2'=>'val2'}
 el = Element.new 'my-tag'
 doc.add_element el

[Source]

# File rexml/element.rb, line 295
    def add_element element, attrs=nil
      raise "First argument must be either an element name, or an Element object" if element.nil?
      el = @elements.add(element)
      attrs.each do |key, value|
        el.attributes[key]=Attribute.new(key,value,self)
      end       if attrs.kind_of? Hash
      el
    end

add_namespace( prefix, uri=nil )

Adds a namespace to this element.

prefix:	the prefix string, or the namespace URI if `uri` is not supplied
uri:	the namespace URI. May be nil, in which `prefix` is used as the URI

Evaluates to: this Element

 a = Element.new("a")
 a.add_namespace("xmlns:foo", "bar" )
 a.add_namespace("foo", "bar")  # shorthand for previous line
 a.add_namespace("twiddle")
 puts a   #-> <a xmlns:foo='bar' xmlns='twiddle'/>

[Source]

# File rexml/element.rb, line 250
    def add_namespace( prefix, uri=nil )
      unless uri
        @attributes["xmlns"] = prefix
      else
        prefix = "xmlns:#{prefix}" unless prefix =~ /^xmlns:/
        @attributes[ prefix ] = uri
      end
      self
    end

add_text( text )

A helper method to add a Text child. Actual Text instances can be added with regular Parent methods, such as add() and <<()

text:	if a String, a new Text instance is created and added to the parent. If Text, the object is added directly.
Returns:	this Element

 e = Element.new('a')          #-> <e/>
 e.add_text 'foo'              #-> <e>foo</e>
 e.add_text Text.new(' bar')    #-> <e>foo bar</e>

Note that at the end of this example, the branch has 3 nodes; the ‘e’ element and 2 Text node children.

[Source]

# File rexml/element.rb, line 522
    def add_text( text )
      if text.kind_of? String 
        if @children[-1].kind_of? Text
          @children[-1] << text
          return
        end
        text = Text.new( text, whitespace(), nil, raw() )
      end
      self << text unless text.nil?
      return self
    end

attribute( name, namespace=nil )

Attributes #

[Source]

# File rexml/element.rb, line 553
    def attribute( name, namespace=nil )
      prefix = nil
      prefix = namespaces.index(namespace) if namespace
      prefix = nil if prefix == 'xmlns'
      attributes.get_attribute( "#{prefix ? prefix + ':' : ''}#{name}" )
    end

cdatas()

Get an array of all CData children. IMMUTABLE

[Source]

# File rexml/element.rb, line 627
    def cdatas
      find_all { |child| child.kind_of? CData }.freeze
    end

clone()

Creates a shallow copy of self.

  d = Document.new "<a><b/><b/><c><d/></c></a>"
  new_a = d.root.clone
  puts new_a  # => "<a/>"

[Source]

# File rexml/element.rb, line 96
    def clone
      self.class.new self
    end

comments()

Get an array of all Comment children. IMMUTABLE

[Source]

# File rexml/element.rb, line 633
    def comments
      find_all { |child| child.kind_of? Comment }.freeze
    end

delete_attribute(key)

Removes an attribute

key:	either an Attribute or a String. In either case, the attribute is found by matching the attribute name to the argument, and then removed. If no attribute is found, no action is taken.
Returns:	the attribute removed, or nil if this Element did not contain a matching attribute

 e = Element.new('E')
 e.add_attribute( 'name', 'Sean' )             #-> <E name='Sean'/>
 r = e.add_attribute( 'sur:name', 'Russell' )  #-> <E name='Sean' sur:name='Russell'/>
 e.delete_attribute( 'name' )                  #-> <E sur:name='Russell'/>
 e.delete_attribute( r )                       #-> <E/>

[Source]

# File rexml/element.rb, line 616
    def delete_attribute(key)
      attr = @attributes.get_attribute(key)
      attr.remove unless attr.nil?
    end

delete_element(element)

Deletes a child element.

element:	Must be an `Element`, `String`, or `Integer`. If Element, the element is removed. If String, the element is found (via XPath) and removed. <em>This means that any parent can remove any descendant.<em> If Integer, the Element indexed by that number will be removed.
Returns:	the element that was removed.

 doc.delete_element "/a/b/c[@id='4']"
 doc.delete_element doc.elements["//k"]
 doc.delete_element 1

[Source]

# File rexml/element.rb, line 315
    def delete_element element
      @elements.delete element
    end

delete_namespace(namespace="xmlns")

Removes a namespace from this node. This only works if the namespace is actually declared in this node. If no argument is passed, deletes the default namespace.

Evaluates to: this element

 doc = Document.new "<a xmlns:foo='bar' xmlns='twiddle'/>"
 doc.root.delete_namespace
 puts doc     # -> <a xmlns:foo='bar'/>
 doc.root.delete_namespace 'foo'
 puts doc     # -> <a/>

[Source]

# File rexml/element.rb, line 270
    def delete_namespace namespace="xmlns"
      namespace = "xmlns:#{namespace}" unless namespace == 'xmlns'
      attribute = attributes.get_attribute(namespace)
      attribute.remove unless attribute.nil?
      self
    end

document()

Evaluates to the document to which this element belongs, or nil if this element doesn‘t belong to a document.

[Source]

# File rexml/element.rb, line 131
    def document
      rt = root
      rt.parent if rt
    end

each_element( xpath=nil ) {|Element| ...}

Synonym for Element.elements.each

[Source]

# File rexml/element.rb, line 392
    def each_element( xpath=nil, &block ) # :yields: Element
      @elements.each( xpath, &block )
    end

each_element_with_attribute( key, value=nil, max=0, name=nil ) {|Element| ...}

Iterates through the child elements, yielding for each Element that has a particular attribute set.

key:	the name of the attribute to search for
value:	the value of the attribute
max:	(optional) causes this method to return after yielding for this number of matching children
name:	(optional) if supplied, this is an XPath that filters the children to check.

 doc = Document.new "<a><b @id='1'/><c @id='2'/><d @id='1'/><e/></a>"
 # Yields b, c, d
 doc.root.each_element_with_attribute( 'id' ) {|e| p e}
 # Yields b, d
 doc.root.each_element_with_attribute( 'id', '1' ) {|e| p e}
 # Yields b
 doc.root.each_element_with_attribute( 'id', '1', 1 ) {|e| p e}
 # Yields d
 doc.root.each_element_with_attribute( 'id', '1', 0, 'd' ) {|e| p e}

[Source]

# File rexml/element.rb, line 350
    def each_element_with_attribute( key, value=nil, max=0, name=nil, &block ) # :yields: Element
      each_with_something( proc {|child| 
        if value.nil?
          child.attributes[key] != nil
        else
          child.attributes[key]==value
        end
      }, max, name, &block )
    end

each_element_with_text( text=nil, max=0, name=nil ) {|Element| ...}

Iterates through the children, yielding for each Element that has a particular text set.

text:	the text to search for. If nil, or not supplied, will itterate over all `Element` children that contain at least one `Text` node.
max:	(optional) causes this method to return after yielding for this number of matching children
name:	(optional) if supplied, this is an XPath that filters the children to check.

 doc = Document.new '<a><b>b</b><c>b</c><d>d</d><e/></a>'
 # Yields b, c, d
 doc.each_element_with_text {|e|p e}
 # Yields b, c
 doc.each_element_with_text('b'){|e|p e}
 # Yields b
 doc.each_element_with_text('b', 1){|e|p e}
 # Yields d
 doc.each_element_with_text(nil, 0, 'd'){|e|p e}

[Source]

# File rexml/element.rb, line 381
    def each_element_with_text( text=nil, max=0, name=nil, &block ) # :yields: Element
      each_with_something( proc {|child| 
        if text.nil?
          child.has_text?
        else
          child.text == text
        end
      }, max, name, &block )
    end

get_elements( xpath )

Synonym for Element.to_a This is a little slower than calling elements.each directly.

xpath:	any XPath by which to search for elements in the tree
Returns:	an array of Elements that match the supplied path

[Source]

# File rexml/element.rb, line 400
    def get_elements( xpath )
      @elements.to_a( xpath )
    end

get_text(path = nil)

Returns the first child Text node, if any, or nil otherwise. This method returns the actual Text node, rather than the String content.

 doc = Document.new "<p>some text <b>this is bold!</b> more text</p>"
 # The element 'p' has two text elements, "some text " and " more text".
 doc.root.get_text.value            #-> "some text "

[Source]

# File rexml/element.rb, line 461
    def get_text path = nil
      rv = nil
      if path
        element = @elements[ path ]
        rv = element.get_text unless element.nil?
      else
        rv = @children.find { |node| node.kind_of? Text }
      end
      return rv
    end

has_attributes?()

Evaluates to true if this element has any attributes set, false otherwise.

[Source]

# File rexml/element.rb, line 562
    def has_attributes?
      return !@attributes.empty?
    end

has_elements?()

Evaluates to true if this element has at least one child Element

 doc = Document.new "<a><b/><c>Text</c></a>"
 doc.root.has_elements               # -> true
 doc.elements["/a/b"].has_elements   # -> false
 doc.elements["/a/c"].has_elements   # -> false

[Source]

# File rexml/element.rb, line 324
    def has_elements?
      !@elements.empty?
    end

has_text?()

Evaluates to true if this element has at least one Text child

[Source]

# File rexml/element.rb, line 432
    def has_text?
      not text().nil?
    end

ignore_whitespace_nodes()

[Source]

# File rexml/element.rb, line 161
    def ignore_whitespace_nodes
      @ignore_whitespace_nodes = false
      if @context
        if @context[:ignore_whitespace_nodes]
          @ignore_whitespace_nodes = 
            (@context[:ignore_whitespace_nodes] == :all or
             @context[:ignore_whitespace_nodes].include? expanded_name)
        end
      end
    end

inspect()

[Source]

# File rexml/element.rb, line 76
    def inspect
      rv = "<#@expanded_name"

      @attributes.each_attribute do |attr|
        rv << " "
        attr.write( rv, 0 )
      end

      if children.size > 0
        rv << "> ... </>"
      else
        rv << "/>"
      end
    end

instructions()

Get an array of all Instruction children. IMMUTABLE

[Source]

# File rexml/element.rb, line 639
    def instructions
      find_all { |child| child.kind_of? Instruction }.freeze
    end

namespace(prefix=nil)

Evalutas to the URI for a prefix, or the empty string if no such namespace is declared for this element. Evaluates recursively for ancestors. Returns the default namespace, if there is one.

prefix:	the prefix to search for. If not supplied, returns the default namespace if one exists
Returns:	the namespace URI as a String, or nil if no such namespace exists. If the namespace is undefined, returns an empty string

 doc = Document.new("<a xmlns='1' xmlns:y='2'><b/><c xmlns:z='3'/></a>")
 b = doc.elements['//b']
 b.namespace           # -> '1'
 b.namespace("y")      # -> '2'

[Source]

# File rexml/element.rb, line 222
    def namespace(prefix=nil)
      if prefix.nil?
        prefix = prefix()
      end
      if prefix == ''
        prefix = "xmlns"
      else
        prefix = "xmlns:#{prefix}" unless prefix[0,5] == 'xmlns'
      end
      ns = attributes[ prefix ]
      ns = parent.namespace(prefix) if ns.nil? and parent
      ns = '' if ns.nil? and prefix == 'xmlns'
      return ns
    end

namespaces()

[Source]

# File rexml/element.rb, line 202
    def namespaces
      namespaces = {}
      namespaces = parent.namespaces if parent
      namespaces = namespaces.merge( attributes.namespaces )
      return namespaces
    end

next_element()

Returns the next sibling that is an element, or nil if there is no Element sibling after this one

 doc = Document.new '<a><b/>text<c/></a>'
 doc.root.elements['b'].next_element          #-> <c/>
 doc.root.elements['c'].next_element          #-> nil

[Source]

# File rexml/element.rb, line 409
    def next_element
      element = next_sibling
      element = element.next_sibling until element.nil? or element.kind_of? Element 
      return element
    end

node_type()

[Source]

# File rexml/element.rb, line 534
    def node_type
      :element
    end

prefixes()

Evaluates to an Array containing the prefixes (names) of all defined namespaces at this context node.

 doc = Document.new("<a xmlns:x='1' xmlns:y='2'><b/><c xmlns:z='3'/></a>")
 doc.elements['//b'].prefixes # -> ['x', 'y']

[Source]

# File rexml/element.rb, line 195
    def prefixes
      prefixes = []
      prefixes = parent.prefixes if parent
      prefixes |= attributes.prefixes
      return prefixes
    end

previous_element()

Returns the previous sibling that is an element, or nil if there is no Element sibling prior to this one

 doc = Document.new '<a><b/>text<c/></a>'
 doc.root.elements['c'].previous_element          #-> <b/>
 doc.root.elements['b'].previous_element          #-> nil

[Source]

# File rexml/element.rb, line 420
    def previous_element
      element = previous_sibling
      element = element.previous_sibling until element.nil? or element.kind_of? Element
      return element
    end

raw()

Evaluates to true if raw mode is set for this element. This is the case if the context has :raw set to :all or an array containing the name of this element.

The evaluation is tested against expanded_name, and so is namespace sensitive.

[Source]

# File rexml/element.rb, line 178
    def raw
      @raw = (@context and @context[:raw] and
              (@context[:raw] == :all or
               @context[:raw].include? expanded_name))
               @raw
    end

root()

[Source]

# File rexml/element.rb, line 123
    def root
      return elements[1] if self.kind_of? Document
      return self if parent.kind_of? Document or parent.nil?
      return parent.root
    end

root_node()

Evaluates to the root node of the document that this element belongs to. If this element doesn‘t belong to a document, but does belong to another Element, the parent‘s root will be returned, until the earliest ancestor is found.

Note that this is not the same as the document element. In the following example, <a> is the document element, and the root node is the parent node of the document element. You may ask yourself why the root node is useful: consider the doctype and XML declaration, and any processing instructions before the document element… they are children of the root node, or siblings of the document element. The only time this isn‘t true is when an Element is created that is not part of any Document. In this case, the ancestor that has no parent acts as the root node.

 d = Document.new '<a><b><c/></b></a>'
 a = d[1] ; c = a[1][1]
 d.root_node == d   # TRUE
 a.root_node        # namely, d
 c.root_node        # again, d

[Source]

# File rexml/element.rb, line 119
    def root_node
      parent.nil? ? self : parent.root_node
    end

text( path = nil )

A convenience method which returns the String value of the first child text element, if one exists, and nil otherwise.

Note that an element may have multiple Text elements, perhaps separated by other children. Be aware that this method only returns the first Text node.

This method returns the value of the first text child node, which ignores the raw setting, so always returns normalized text. See the Text::value documentation.

 doc = Document.new "<p>some text <b>this is bold!</b> more text</p>"
 # The element 'p' has two text elements, "some text " and " more text".
 doc.root.text              #-> "some text "

[Source]

# File rexml/element.rb, line 450
    def text( path = nil )
      rv = get_text(path)
      return rv.value unless rv.nil?
      nil
    end

text=( text )

Sets the first Text child of this object. See text() for a discussion about Text children.

If a Text child already exists, the child is replaced by this content. This means that Text content can be deleted by calling this method with a nil argument. In this case, the next Text child becomes the first Text child. In no case is the order of any siblings disturbed.

text:	If a String, a new Text child is created and added to this Element as the first Text child. If Text, the text is set as the first Child element. If nil, then any existing first Text child is removed.
Returns:	this Element.

 doc = Document.new '<a><b/></a>'
 doc.root.text = 'Sean'      #-> '<a><b/>Sean</a>'
 doc.root.text = 'Elliott'   #-> '<a><b/>Elliott</a>'
 doc.root.add_element 'c'    #-> '<a><b/>Elliott<c/></a>'
 doc.root.text = 'Russell'   #-> '<a><b/>Russell<c/></a>'
 doc.root.text = nil         #-> '<a><b/><c/></a>'

[Source]

# File rexml/element.rb, line 492
    def text=( text )
      if text.kind_of? String
        text = Text.new( text, whitespace(), nil, raw() )
      elsif text and !text.kind_of? Text
        text = Text.new( text.to_s, whitespace(), nil, raw() )
      end
      old_text = get_text
      if text.nil?
        old_text.remove unless old_text.nil?
      else
        if old_text.nil?
          self << text
        else
          old_text.replace_with( text )
        end
      end
      return self
    end

texts()

Get an array of all Text children. IMMUTABLE

[Source]

# File rexml/element.rb, line 645
    def texts
      find_all { |child| child.kind_of? Text }.freeze
    end

whitespace()

Evaluates to true if whitespace is respected for this element. This is the case if:

Neither :respect_whitespace nor :compress_whitespace has any value
The context has :respect_whitespace set to :all or an array containing the name of this element, and :compress_whitespace isn‘t set to :all or an array containing the name of this element.

The evaluation is tested against expanded_name, and so is namespace sensitive.

[Source]

# File rexml/element.rb, line 145
    def whitespace
      @whitespace = nil
      if @context
        if @context[:respect_whitespace]
          @whitespace = (@context[:respect_whitespace] == :all or
                         @context[:respect_whitespace].include? expanded_name)
        end
        @whitespace = false if (@context[:compress_whitespace] and
                                (@context[:compress_whitespace] == :all or
                                 @context[:compress_whitespace].include? expanded_name)
                               )
      end
      @whitespace = true unless @whitespace == false
      @whitespace
    end

write(writer=$stdout, indent=-1, transitive=false, ie_hack=false)

DEPRECATED

See REXML::Formatters

Writes out this element, and recursively, all children.

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 this number of spaces, and children will be indented an additional amount. 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 parse tree of the document
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

 out = ''
 doc.write( out )     #-> doc is written to the string 'out'
 doc.write( $stdout ) #-> doc written to the console

[Source]

# File rexml/element.rb, line 674
    def write(writer=$stdout, indent=-1, transitive=false, ie_hack=false)
      Kernel.warn("#{self.class.name}.write is deprecated.  See REXML::Formatters")
      formatter = if indent > -1
          if 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

xpath()

[Source]

# File rexml/element.rb, line 538
    def xpath
      path_elements = []
      cur = self
      path_elements << __to_xpath_helper( self )
      while cur.parent
        cur = cur.parent
        path_elements << __to_xpath_helper( cur )
      end
      return path_elements.reverse.join( "/" )
    end

attributes	[R]	Mechanisms for accessing attributes and child elements of this element.
context	[RW]	The context holds information about the processing environment, such as whitespace handling.
elements	[R]	Mechanisms for accessing attributes and child elements of this element.

Methods

Included Modules

Constants

Attributes

Public Class methods

Public Instance methods

DEPRECATED