Class: XML::XXPath::NameAndIndexStep

Inherits:
Step
  • Object
show all
Defined in:
lib/xml/xxpath/steps.rb

Overview

:nodoc:

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Step

#creator, inherited

Constructor Details

#initialize(axis, name, index) ⇒ NameAndIndexStep

Returns a new instance of NameAndIndexStep.



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# File 'lib/xml/xxpath/steps.rb', line 154

def initialize(axis,name,index)
  super(axis)
  @name,@index = name,index
end

Class Method Details

.compile(axis, string) ⇒ Object 



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# File 'lib/xml/xxpath/steps.rb', line 149

def self.compile axis, string
  /^(.*?)\[(\d+)\]$/ === string or return nil
  self.new axis,$1,$2.to_i
end

Instance Method Details

#create_on(node, create_new) ⇒ Object 



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# File 'lib/xml/xxpath/steps.rb', line 164

def create_on(node,create_new)
  name_matches = node.elements.select{|elt| elt.name==@name}
  if create_new and (name_matches.size >= @index)
    raise XXPathError, "XPath: #{@name}[#{@index}]: create_new and element already exists"
  end
  newnode = name_matches[0]
  (@index-name_matches.size).times do
    newnode = node.elements.add @name
  end
  newnode
end

#matches?(node) ⇒ Boolean

Returns:

  • (Boolean)

Raises:



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# File 'lib/xml/xxpath/steps.rb', line 159

def matches? node
  raise XXPathError, "can't use #{@name}[#{@index}] on root node" if node.parent.nil?
  node == node.parent.elements.select{|elt| elt.name==@name}[@index-1]
end

#reader(prev_reader, creator_from_here) ⇒ Object 



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# File 'lib/xml/xxpath/steps.rb', line 176

def reader(prev_reader,creator_from_here)
  if @axis==:child
    index = @index - 1
    proc {|nodes|
      next_nodes = []
      nodes.each do |node|
        byname=node.elements.select{|elt| elt.name==@name}
        next_nodes << byname[index] if index<byname.size
      end
      if (next_nodes.empty?)
        throw :not_found, [nodes,creator_from_here]
      else
        prev_reader.call(next_nodes)
      end
    }
  else
    super(prev_reader,creator_from_here)
  end
end