Module REXML::Functions
In: rexml/functions.rb

If you add a method, keep in mind two things: (1) the first argument will always be a list of nodes from which to filter. In the case of context methods (such as position), the function should return an array with a value for each child in the array. (2) all method calls from XML will have "-" replaced with "_". Therefore, in XML, "local-name()" is identical (and actually becomes) "local_name()"

Methods

Public Class methods

UNTESTED

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# File rexml/functions.rb, line 255
    def Functions::boolean( object=nil )
      if object.kind_of? String
        if object =~ /\d+/u
          return object.to_f != 0
        else
          return object.size > 0
        end
      elsif object.kind_of? Array
        object = object.find{|x| x and true}
      end
      return object ? true : false
    end

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# File rexml/functions.rb, line 350
    def Functions::ceiling( number )
      number(number).ceil
    end

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# File rexml/functions.rb, line 302
    def Functions::compare_language lang1, lang2
      lang2.downcase.index(lang1.downcase) == 0
    end

UNTESTED

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# File rexml/functions.rb, line 132
    def Functions::concat( *objects )
      objects.join
    end

Fixed by Mike Stok

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# File rexml/functions.rb, line 142
    def Functions::contains( string, test )
      string(string).include? string(test)
    end

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# File rexml/functions.rb, line 19
    def Functions::context=(value); @@context = value; end

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# File rexml/functions.rb, line 39
    def Functions::count( node_set )
      node_set.size
    end

UNTESTED

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# File rexml/functions.rb, line 279
    def Functions::false(  )
      false
    end

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# File rexml/functions.rb, line 346
    def Functions::floor( number )
      number(number).floor
    end

Helper method.

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# File rexml/functions.rb, line 66
    def Functions::get_namespace( node_set = nil )
      if node_set == nil
        yield @@context[:node] if defined? @@context[:node].namespace
      else  
        if node_set.namespace
          yield node_set
        else
          return unless node_set.kind_of? Enumerable
          node_set.each { |node| yield node if defined? node.namespace }
        end
      end
    end

Since REXML is non-validating, this method is not implemented as it requires a DTD

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# File rexml/functions.rb, line 45
    def Functions::id( object )
    end

UNTESTED

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# File rexml/functions.rb, line 284
    def Functions::lang( language )
      lang = false
      node = @@context[:node]
      attr = nil
      until node.nil?
        if node.node_type == :element
          attr = node.attributes["xml:lang"]
          unless attr.nil?
            lang = compare_language(string(language), attr)
            break
          else
          end
        end
        node = node.parent
      end
      lang
    end

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# File rexml/functions.rb, line 31
    def Functions::last( )
      @@context[:size]
    end

UNTESTED

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# File rexml/functions.rb, line 49
    def Functions::local_name( node_set=nil )
      get_namespace( node_set ) do |node|
        return node.local_name 
      end
    end

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# File rexml/functions.rb, line 366
    def Functions::method_missing( id )
      puts "METHOD MISSING #{id.id2name}"
      XPath.match( @@context[:node], id.id2name )
    end

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# File rexml/functions.rb, line 59
    def Functions::name( node_set=nil )
      get_namespace( node_set ) do |node| 
        node.expanded_name
      end
    end

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# File rexml/functions.rb, line 16
    def Functions::namespace_context ; @@namespace_context ; end

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# File rexml/functions.rb, line 14
    def Functions::namespace_context=(x) ; @@namespace_context=x ; end

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# File rexml/functions.rb, line 55
    def Functions::namespace_uri( node_set=nil )
      get_namespace( node_set ) {|node| node.namespace}
    end

UNTESTED

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# File rexml/functions.rb, line 208
    def Functions::normalize_space( string=nil )
      string = string(@@context[:node]) if string.nil?
      if string.kind_of? Array
        string.collect{|x| string.to_s.strip.gsub(/\s+/um, ' ') if string}
      else
        string.to_s.strip.gsub(/\s+/um, ' ')
      end
    end

UNTESTED

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# File rexml/functions.rb, line 269
    def Functions::not( object )
      not boolean( object )
    end

a string that consists of optional whitespace followed by an optional minus sign followed by a Number followed by whitespace is converted to the IEEE 754 number that is nearest (according to the IEEE 754 round-to-nearest rule) to the mathematical value represented by the string; any other string is converted to NaN

boolean true is converted to 1; boolean false is converted to 0

a node-set is first converted to a string as if by a call to the string function and then converted in the same way as a string argument

an object of a type other than the four basic types is converted to a number in a way that is dependent on that type

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# File rexml/functions.rb, line 319
    def Functions::number( object=nil )
      object = @@context[:node] unless object
      case object
      when true
        Float(1)
      when false
        Float(0)
      when Array
        number(string( object ))
      when Numeric
        object.to_f
      else
        str = string( object )
        #puts "STRING OF #{object.inspect} = #{str}"
        if str =~ /^\d+/
          object.to_s.to_f
        else
          (0.0 / 0.0)
        end
      end
    end

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# File rexml/functions.rb, line 35
    def Functions::position( )
      @@context[:index]
    end

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# File rexml/functions.rb, line 362
    def Functions::processing_instruction( node )
      node.node_type == :processing_instruction
    end

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# File rexml/functions.rb, line 354
    def Functions::round( number )
      begin
        number(number).round
      rescue FloatDomainError
        number(number)
      end
    end

Fixed by Mike Stok

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# File rexml/functions.rb, line 137
    def Functions::starts_with( string, test )
      string(string).index(string(test)) == 0
    end

A node-set is converted to a string by returning the string-value of the node in the node-set that is first in document order. If the node-set is empty, an empty string is returned.

A number is converted to a string as follows

NaN is converted to the string NaN

positive zero is converted to the string 0

negative zero is converted to the string 0

positive infinity is converted to the string Infinity

negative infinity is converted to the string -Infinity

if the number is an integer, the number is represented in decimal form as a Number with no decimal point and no leading zeros, preceded by a minus sign (-) if the number is negative

otherwise, the number is represented in decimal form as a Number including a decimal point with at least one digit before the decimal point and at least one digit after the decimal point, preceded by a minus sign (-) if the number is negative; there must be no leading zeros before the decimal point apart possibly from the one required digit immediately before the decimal point; beyond the one required digit after the decimal point there must be as many, but only as many, more digits as are needed to uniquely distinguish the number from all other IEEE 754 numeric values.

The boolean false value is converted to the string false. The boolean true value is converted to the string true.

An object of a type other than the four basic types is converted to a string in a way that is dependent on that type.

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# File rexml/functions.rb, line 114
    def Functions::string( object=nil )
      #object = @context unless object
      if object.instance_of? Array
        string( object[0] )
      elsif defined? object.node_type
        if object.node_type == :attribute
          object.value
        elsif object.node_type == :element
          object.text
        else
          object.to_s
        end
      else
        object.to_s
      end
    end

UNTESTED

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# File rexml/functions.rb, line 203
    def Functions::string_length( string )
      string(string).length
    end

Take equal portions of Mike Stok and Sean Russell; mix vigorously, and pour into a tall, chilled glass. Serves 10,000.

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# File rexml/functions.rb, line 170
    def Functions::substring( string, start, length=nil )
      ruby_string = string(string)
      ruby_length = if length.nil? 
                      ruby_string.length.to_f
                    else
                      number(length)
                    end
      ruby_start = number(start)

      # Handle the special cases
      return '' if (
        ruby_length.nan? or 
        ruby_start.nan? or
        ruby_start.infinite?
      )

      infinite_length = ruby_length.infinite? == 1
      ruby_length = ruby_string.length if infinite_length
        
      # Now, get the bounds.  The XPath bounds are 1..length; the ruby bounds 
      # are 0..length.  Therefore, we have to offset the bounds by one.
      ruby_start = ruby_start.round - 1
      ruby_length = ruby_length.round

      if ruby_start < 0
       ruby_length += ruby_start unless infinite_length
       ruby_start = 0
      end
      return '' if ruby_length <= 0
      ruby_string[ruby_start,ruby_length]
    end

Kouhei fixed this too

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# File rexml/functions.rb, line 158
    def Functions::substring_after( string, test )
      ruby_string = string(string)
      ruby_index = ruby_string.index(string(test))
      if ruby_index.nil?
        ""
      else
        ruby_string[ ruby_index+1..-1 ]
      end
    end

Kouhei fixed this

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# File rexml/functions.rb, line 147
    def Functions::substring_before( string, test )
      ruby_string = string(string)
      ruby_index = ruby_string.index(string(test))
      if ruby_index.nil?
        ""
      else
        ruby_string[ 0...ruby_index ]
      end
    end

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# File rexml/functions.rb, line 341
    def Functions::sum( nodes )
      nodes = [nodes] unless nodes.kind_of? Array
      nodes.inject(0) { |r,n| r += number(string(n)) }
    end

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# File rexml/functions.rb, line 21
    def Functions::text( )
      if @@context[:node].node_type == :element
        return @@context[:node].find_all{|n| n.node_type == :text}.collect{|n| n.value}
      elsif @@context[:node].node_type == :text
        return @@context[:node].value
      else
        return false
      end
    end

This is entirely Mike Stok’s beast

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# File rexml/functions.rb, line 218
    def Functions::translate( string, tr1, tr2 )
      from = string(tr1)
      to = string(tr2)

      # the map is our translation table.
      #
      # if a character occurs more than once in the
      # from string then we ignore the second &
      # subsequent mappings
      #
      # if a charactcer maps to nil then we delete it
      # in the output.  This happens if the from
      # string is longer than the to string
      #
      # there's nothing about - or ^ being special in
      # http://www.w3.org/TR/xpath#function-translate
      # so we don't build ranges or negated classes

      map = Hash.new
      0.upto(from.length - 1) { |pos|
        from_char = from[pos]
        unless map.has_key? from_char
          map[from_char] = 
          if pos < to.length
            to[pos]
          else
            nil
          end
        end
      }

      string(string).unpack('U*').collect { |c|
        if map.has_key? c then map[c] else c end
      }.compact.pack('U*')
    end

UNTESTED

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# File rexml/functions.rb, line 274
    def Functions::true( )
      true
    end

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# File rexml/functions.rb, line 17
    def Functions::variables ; @@variables ; end

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# File rexml/functions.rb, line 15
    def Functions::variables=(x) ; @@variables=x ; end

[Validate]