class REXML::Elements

Constructor

parent

the parent Element

# File lib/rexml/element.rb, line 741
def initialize parent
  @element = parent
end

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"/>

# File lib/rexml/element.rb, line 766
def []( index, name=nil)
  if index.kind_of? Integer
    raise "index (#{index}) must be >= 1" if index < 1
    name = literalize(name) if name
    num = 0
    @element.find { |child|
      child.kind_of? Element and
      (name.nil? ? true : child.has_name?( name )) and
      (num += 1) == index
    }
  else
    return XPath::first( @element, index )
    #{ |element|
    #       return element if element.kind_of? Element
    #}
    #return nil
  end
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>

# File lib/rexml/element.rb, line 798
def []=( index, element )
  previous = self[index]
  if previous.nil?
    @element.add element
  else
    previous.replace_with element
  end
  return previous
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>

# File lib/rexml/element.rb, line 874
def add element=nil
  if element.nil?
    Element.new("", self, @element.context)
  elsif not element.kind_of?(Element)
    Element.new(element, self, @element.context)
  else
    @element << element
    element.context = @element.context
    element
  end
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/>

# File lib/rexml/element.rb, line 838
def delete element
  if element.kind_of? Element
    @element.delete element
  else
    el = self[element]
    el.remove if el
  end
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/>]

# File lib/rexml/element.rb, line 853
def delete_all( xpath )
  rv = []
  XPath::each( @element, xpath) {|element|
    rv << element if element.kind_of? Element
  }
  rv.each do |element|
    @element.delete element
    element.remove
  end
  return rv
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.elements.each {|e|p e}       #-> Yields b, c, d, b, c, d elements
doc.root.elements.each('b') {|e|p e}  #-> Yields b, b elements
doc.root.elements.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/>

# File lib/rexml/element.rb, line 902
def each( xpath=nil )
  XPath::each( @element, xpath ) {|e| yield e if e.kind_of? Element }
end

Returns true if there are no Element children, false otherwise

# File lib/rexml/element.rb, line 809
def empty?
  @element.find{ |child| child.kind_of? Element}.nil?
end

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

element

an Element child

# File lib/rexml/element.rb, line 816
def index element
  rv = 0
  found = @element.find do |child|
    child.kind_of? Element and
    (rv += 1) and
    child == element
  end
  return rv if found == element
  return -1
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

# File lib/rexml/element.rb, line 933
def size
  count = 0
  @element.each {|child| count+=1 if child.kind_of? Element }
  count
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/> ]

# File lib/rexml/element.rb, line 946
def to_a( xpath=nil )
  rv = XPath.match( @element, xpath )
  return rv.find_all{|e| e.kind_of? Element} if xpath
  rv
end

Private helper class. Removes quotes from quoted strings

# File lib/rexml/element.rb, line 954
def literalize name
  name = name[1..-2] if name[0] == ?' or name[0] == ?"               #'
  name
end