Module: REXML::Functions

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In: QuickPath, XPath
Defined in:	lib/rexml/functions.rb

Overview

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()”

Constant Summary

INTERNAL_METHODS =
# File 'lib/rexml/functions.rb', line 16

[
  :namespace_context,
  :namespace_context=,
  :variables,
  :variables=,
  :context=,
  :get_namespace,
  :send,
]

Class Method Summary

.boolean(object = nil)

UNTESTED.
.ceiling(number)
.compare_language(lang1, lang2)
.concat(*objects)

UNTESTED.
.contains(string, test)

Fixed by Mike Stok.
.count(node_set)

Returns the size of the given list of nodes.
.false

UNTESTED.
.floor(number)
.get_namespace(node_set = nil)

Helper method.
.id(object)

Since REXML is non-validating, this method is not implemented as it requires a DTD.
.lang(language)

UNTESTED.
.last

Returns the last node of the given list of nodes.
.local_name(node_set = nil)

UNTESTED.
.name(node_set = nil)
.namespace_uri(node_set = nil)
.normalize_space(string = nil)

UNTESTED.
.not(object)

UNTESTED.
.number(object = nil)

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.
.position
.processing_instruction(node)
.round(number)
.send(name, *args)
.singleton_method_added(name)
.starts_with(string, test)

Fixed by Mike Stok.
.string(object = nil)

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.
.string_length(string)

UNTESTED.
.string_value(o)

A node-set is converted to a string by returning the concatenation of the string-value of each of the children of the node in the node-set that is first in document order.
.substring(string, start, length = nil)

Take equal portions of Mike Stok and Sean Russell; mix vigorously, and pour into a tall, chilled glass.
.substring_after(string, test)

Kouhei fixed this too.
.substring_before(string, test)

Kouhei fixed this.
.sum(nodes)
.text
.translate(string, tr1, tr2)

This is entirely Mike Stok's beast.
.true

UNTESTED.

Class Attribute Details

.context=(value) (writeonly)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 38


def Functions::context=(value); @@context = value; end

.namespace_context (rw)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 35


def Functions::namespace_context ; @@namespace_context ; end

.namespace_context=(x) (rw)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 33


def Functions::namespace_context=(x) ; @@namespace_context=x ; end

.variables (rw)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 36


def Functions::variables ; @@variables ; end

.variables=(x) (rw)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 34


def Functions::variables=(x) ; @@variables=x ; end

Class Method Details

.boolean(object = nil)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 296


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

.ceiling(number)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 392


def Functions::ceiling( number )
  number(number).ceil
end

.compare_language(lang1, lang2)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 343


def Functions::compare_language lang1, lang2
  lang2.downcase.index(lang1.downcase) == 0
end

.concat(*objects)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 171


def Functions::concat( *objects )
  objects.join
end

.contains(string, test)

Fixed by Mike Stok

[ GitHub ]

# File 'lib/rexml/functions.rb', line 181


def Functions::contains( string, test )
  string(string).include?(string(test))
end

.count(node_set)

Returns the size of the given list of nodes.

[ GitHub ]

# File 'lib/rexml/functions.rb', line 60


def Functions::count( node_set )
  node_set.size
end

.false

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 320


def Functions::false(  )
  false
end

.floor(number)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 388


def Functions::floor( number )
  number(number).floor
end

.get_namespace(node_set = nil)

Helper method.

[ GitHub ]

# File 'lib/rexml/functions.rb', line 87


def Functions::get_namespace( node_set = nil )
  if node_set == nil
    yield @@context[:node] if defined? @@context[:node].namespace
  else
    if node_set.respond_to? :each
      node_set.each { |node| yield node if defined? node.namespace }
    elsif node_set.respond_to? :namespace
      yield node_set
    end
  end
end

.id(object)

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

[ GitHub ]

# File 'lib/rexml/functions.rb', line 66


def Functions::id( object )
end

.lang(language)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 325


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

.last

Returns the last node of the given list of nodes.

[ GitHub ]

# File 'lib/rexml/functions.rb', line 51


def Functions::last( )
  @@context[:size]
end

.local_name(node_set = nil)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 70


def Functions::local_name( node_set=nil )
  get_namespace( node_set ) do |node|
    return node.local_name
  end
end

.name(node_set = nil)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 80


def Functions::name( node_set=nil )
  get_namespace( node_set ) do |node|
    node.expanded_name
  end
end

.namespace_uri(node_set = nil)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 76


def Functions::namespace_uri( node_set=nil )
  get_namespace( node_set ) {|node| node.namespace}
end

.normalize_space(string = nil)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 243


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

.not(object)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 310


def Functions::not( object )
  not boolean( object )
end

.number(object = nil)

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

[ GitHub ]

# File 'lib/rexml/functions.rb', line 360


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 )
    # If XPath ever gets scientific notation...
    #if str =~ /^\s*-?(\d*\.?\d|\d\.)([Ee]\d*)?\s*$/
    if str =~ /^\s*-?(\d*\.?\d|\d\.)\s*$/
      str.to_f
    else
      (0.0 / 0.0)
    end
  end
end

.position

[ GitHub ]

# File 'lib/rexml/functions.rb', line 55


def Functions::position( )
  @@context[:index]
end

.processing_instruction(node)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 404


def Functions::processing_instruction( node )
  node.node_type == :processing_instruction
end

.round(number)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 396


def Functions::round( number )
  begin
    number(number).round
  rescue FloatDomainError
    number(number)
  end
end

.send(name, *args)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 408


def Functions::send(name, *args)
  if @@available_functions[name.to_sym]
    super
  else
    # TODO: Maybe, this is not XPath spec behavior.
    # This behavior must be reconsidered.
    XPath.match(@@context[:node], name.to_s)
  end
end

.singleton_method_added(name)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 26


def singleton_method_added(name)
  unless INTERNAL_METHODS.include?(name)
    @@available_functions[name] = true
  end
end

.starts_with(string, test)

Fixed by Mike Stok

[ GitHub ]

# File 'lib/rexml/functions.rb', line 176


def Functions::starts_with( string, test )
  string(string).index(string(test)) == 0
end

.string(object = nil)

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.

[ GitHub ]

# File 'lib/rexml/functions.rb', line 134


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.node_type == :document
      string_value(object)
    else
      object.to_s
    end
  elsif object.nil?
    return ""
  else
    object.to_s
  end
end

.string_length(string)

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 238


def Functions::string_length( string )
  string(string).length
end

.string_value(o)

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

[ GitHub ]

# File 'lib/rexml/functions.rb', line 158


def Functions::string_value( o )
  rv = ""
  o.children.each { |e|
    if e.node_type == :text
      rv << e.to_s
    elsif e.node_type == :element
      rv << string_value( e )
    end
  }
  rv
end

.substring(string, start, length = nil)

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

[ GitHub ]

# File 'lib/rexml/functions.rb', line 205


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

.substring_after(string, test)

Kouhei fixed this too

[ GitHub ]

# File 'lib/rexml/functions.rb', line 197


def Functions::substring_after( string, test )
  ruby_string = string(string)
  return $1 if ruby_string =~ /#{test}(.*)/
  ""
end

.substring_before(string, test)

Kouhei fixed this

[ GitHub ]

# File 'lib/rexml/functions.rb', line 186


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

.sum(nodes)

[ GitHub ]

# File 'lib/rexml/functions.rb', line 383


def Functions::sum( nodes )
  nodes = [nodes] unless nodes.kind_of? Array
  nodes.inject(0) { |r,n| r + number(string(n)) }
end

.text

[ GitHub ]

# File 'lib/rexml/functions.rb', line 40


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

.translate(string, tr1, tr2)

This is entirely Mike Stok's beast

[ GitHub ]

# File 'lib/rexml/functions.rb', line 253


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 character 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
  }

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

.true

UNTESTED

[ GitHub ]

# File 'lib/rexml/functions.rb', line 315


def Functions::true( )
  true
end