Method: REXML::XPathParser#first

Defined in:
lib/xmpp4r/rexmladdons.rb

#first(path_stack, node) ⇒ Object

Performs a depth-first (document order) XPath search, and returns the first match. This is the fastest, lightest way to return a single result.



173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
 
# File 'lib/xmpp4r/rexmladdons.rb', line 173

def first( path_stack, node )
  #puts "#{depth}) Entering match( #{path.inspect}, #{tree.inspect} )"
  return nil if path.size == 0

  case path[0]
  when :document
    # do nothing 
    return first( path[1..-1], node )
  when :child
    for c in node.children
      #puts "#{depth}) CHILD checking #{name(c)}"
      r = first( path[1..-1], c )
      #puts "#{depth}) RETURNING #{r.inspect}" if r
      return r if r
    end
  when :qname
    name = path[2]
    #puts "#{depth}) QNAME #{name(tree)} == #{name} (path => #{path.size})"
    if node.name == name
      #puts "#{depth}) RETURNING #{tree.inspect}" if path.size == 3
      return node if path.size == 3
      return first( path[3..-1], node )
    else
      return nil
    end
  when :descendant_or_self
    r = first( path[1..-1], node )
    return r if r
    for c in node.children
      r = first( path, c )
      return r if r
    end
  when :node
    return first( path[1..-1], node )
  when :any
    return first( path[1..-1], node )
  end
  return nil
end