Class REXML::Elements
In: lib/rexml/element.rb
Parent: Object

A class which provides filtering of children for Elements, and XPath search support. You are expected to only encounter this class as the element.elements object. Therefore, you are not expected to instantiate this yourself.

Methods

<<   []   []=   add   delete   delete_all   each   empty?   index   literalize   new   size   to_a  

Included Modules

Enumerable

Public Class methods

Constructor

parent:the parent Element

[Source]

     # File lib/rexml/element.rb, line 775
775:                 def initialize parent
776:                         @element = parent
777:                 end

Public Instance methods

<<(element=nil)

Alias for add

Fetches a child element. Filters only Element children, regardless of the XPath match.

index:the search parameter. This is either an Integer, which will be used to find the index‘th child Element, or an XPath, which will be used to search for the Element. Because of the nature of XPath searches, any element in the connected XML document can be fetched through any other element. The Integer index is 1-based, not 0-based. This means that the first child element is at index 1, not 0, and the +n+th element is at index n, not n-1. This is because XPath indexes element children starting from 1, not 0, and the indexes should be the same.
name:optional, and only used in the first argument is an Integer. In that case, the index‘th child Element that has the supplied name will be returned. Note again that the indexes start at 1.
Returns:the first matching Element, or nil if no child matched
 doc = Document.new '<a><b/><c id="1"/><c id="2"/><d/></a>'
 doc.root.elements[1]       #-> <b/>
 doc.root.elements['c']     #-> <c id="1"/>
 doc.root.elements[2,'c']   #-> <c id="2"/>

[Source]

     # File lib/rexml/element.rb, line 800
800:                 def []( index, name=nil)
801:                         if index.kind_of? Integer
802:                                 raise "index (#{index}) must be >= 1" if index < 1
803:                                 name = literalize(name) if name
804:                                 num = 0
805:                                 child = nil
806:                                 @element.find { |child|
807:                                         child.kind_of? Element and
808:                                         (name.nil? ? true : child.has_name?( name )) and 
809:                                         (num += 1) == index
810:                                 }
811:                         else
812:                                 return XPath::first( @element, index )
813:                                 #{ |element| 
814:                                 #   return element if element.kind_of? Element
815:                                 #}
816:                                 #return nil
817:                         end
818:                 end

Sets an element, replacing any previous matching element. If no existing element is found ,the element is added.

index:Used to find a matching element to replace. See []().
element:The element to replace the existing element with the previous element
Returns:nil if no previous element was found.
 doc = Document.new '<a/>'
 doc.root.elements[10] = Element.new('b')    #-> <a><b/></a>
 doc.root.elements[1]                        #-> <b/>
 doc.root.elements[1] = Element.new('c')     #-> <a><c/></a>
 doc.root.elements['c'] = Element.new('d')   #-> <a><d/></a>

[Source]

     # File lib/rexml/element.rb, line 833
833:                 def []=( index, element )
834:                         previous = self[index]
835:                         if previous.nil?
836:                                 @element.add element
837:                         else
838:                                 previous.replace_with element
839:                         end
840:                         return previous
841:                 end

Adds an element

element:if supplied, is either an Element, String, or Source (see Element.initialize). If not supplied or nil, a new, default Element will be constructed
Returns:the added Element
 a = Element.new 'a'
 a.elements.add Element.new 'b'  #-> <a><b/></a>
 a.elements.add 'c'              #-> <a><b/><c/></a>

[Source]

     # File lib/rexml/element.rb, line 909
909:                 def add element=nil
910:                         rv = nil
911:                         if element.nil?
912:                                 Element.new "", self, @element.context
913:                         elsif not element.kind_of?(Element)
914:                                 Element.new element, self, @element.context
915:                         else
916:                                 @element << element
917:                                 element.context = @element.context
918:                                 element
919:                         end
920:                 end

Deletes a child Element

element:Either an Element, which is removed directly; an xpath, where the first matching child is removed; or an Integer, where the n‘th Element is removed.
Returns:the removed child
 doc = Document.new '<a><b/><c/><c id="1"/></a>'
 b = doc.root.elements[1]
 doc.root.elements.delete b           #-> <a><c/><c id="1"/></a>
 doc.elements.delete("a/c[@id='1']")  #-> <a><c/></a>
 doc.root.elements.delete 1           #-> <a/>

[Source]

     # File lib/rexml/element.rb, line 873
873:                 def delete element
874:                         if element.kind_of? Element
875:                                 @element.delete element
876:                         else
877:                                 el = self[element]
878:                                 el.remove if el
879:                         end
880:                 end

Removes multiple elements. Filters for Element children, regardless of XPath matching.

xpath:all elements matching this String path are removed.
Returns:an Array of Elements that have been removed
 doc = Document.new '<a><c/><c/><c/><c/></a>'
 deleted = doc.elements.delete_all 'a/c' #-> [<c/>, <c/>, <c/>, <c/>]

[Source]

     # File lib/rexml/element.rb, line 888
888:                 def delete_all( xpath )
889:                         rv = []
890:                         XPath::each( @element, xpath) {|element| 
891:                                 rv << element if element.kind_of? Element
892:                         }
893:                         rv.each do |element|
894:                                 @element.delete element
895:                                 element.remove
896:                         end
897:                         return rv
898:                 end

Iterates through all of the child Elements, optionally filtering them by a given XPath

xpath:optional. If supplied, this is a String XPath, and is used to filter the children, so that only matching children are yielded. Note that XPaths are automatically filtered for Elements, so that non-Element children will not be yielded
 doc = Document.new '<a><b/><c/><d/>sean<b/><c/><d/></a>'
 doc.root.each {|e|p e}       #-> Yields b, c, d, b, c, d elements
 doc.root.each('b') {|e|p e}  #-> Yields b, b elements
 doc.root.each('child::node()')  {|e|p e}
 #-> Yields <b/>, <c/>, <d/>, <b/>, <c/>, <d/>
 XPath.each(doc.root, 'child::node()', &block)
 #-> Yields <b/>, <c/>, <d/>, sean, <b/>, <c/>, <d/>

[Source]

     # File lib/rexml/element.rb, line 938
938:                 def each( xpath=nil, &block)
939:                         XPath::each( @element, xpath ) {|e| yield e if e.kind_of? Element }
940:                 end

Returns true if there are no Element children, false otherwise

[Source]

     # File lib/rexml/element.rb, line 844
844:                 def empty?
845:                         @element.find{ |child| child.kind_of? Element}.nil?
846:                 end

Returns the index of the supplied child (starting at 1), or -1 if the element is not a child

element:an Element child

[Source]

     # File lib/rexml/element.rb, line 851
851:                 def index element
852:                         rv = 0
853:                         found = @element.find do |child| 
854:                                 child.kind_of? Element and
855:                                 (rv += 1) and
856:                                 child == element
857:                         end
858:                         return rv if found == element
859:                         return -1
860:                 end

Returns the number of Element children of the parent object.

 doc = Document.new '<a>sean<b/>elliott<b/>russell<b/></a>'
 doc.root.size            #-> 6, 3 element and 3 text nodes
 doc.root.elements.size   #-> 3

[Source]

     # File lib/rexml/element.rb, line 946
946:                 def size
947:                         count = 0
948:                         @element.each {|child| count+=1 if child.kind_of? Element }
949:                         count
950:                 end

Returns an Array of Element children. An XPath may be supplied to filter the children. Only Element children are returned, even if the supplied XPath matches non-Element children.

 doc = Document.new '<a>sean<b/>elliott<c/></a>'
 doc.root.elements.to_a                  #-> [ <b/>, <c/> ]
 doc.root.elements.to_a("child::node()") #-> [ <b/>, <c/> ]
 XPath.match(doc.root, "child::node()")  #-> [ sean, <b/>, elliott, <c/> ]

[Source]

     # File lib/rexml/element.rb, line 959
959:                 def to_a( xpath=nil )
960:                         rv = XPath.match( @element, xpath )
961:                         return rv.find_all{|e| e.kind_of? Element} if xpath
962:                         rv
963:                 end

Private Instance methods

Private helper class. Removes quotes from quoted strings

[Source]

     # File lib/rexml/element.rb, line 967
967:                 def literalize name
968:                         name = name[1..-2] if name[0] == ?' or name[0] == ?"               #'
969:                         name
970:                 end

[Validate]