Module: REXML::Functions

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 collapse

@@context = 
nil
@@namespace_context = 
{}
@@variables = 
{}

Class Method Summary collapse

Class Method Details

.boolean(object = nil) ⇒ Object

UNTESTED



265
266
267
268
269
270
271
272
273
274
275
276
 
# File 'lib/rexml/functions.rb', line 265

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) ⇒ Object 



361
362
363
 
# File 'lib/rexml/functions.rb', line 361

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

.compare_language(lang1, lang2) ⇒ Object 



312
313
314
 
# File 'lib/rexml/functions.rb', line 312

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

.concat(*objects) ⇒ Object

UNTESTED



145
146
147
 
# File 'lib/rexml/functions.rb', line 145

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

.contains(string, test) ⇒ Object

Fixed by Mike Stok



155
156
157
 
# File 'lib/rexml/functions.rb', line 155

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

.context=(value) ⇒ Object 



19
 
# File 'lib/rexml/functions.rb', line 19

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

.count(node_set) ⇒ Object 



39
40
41
 
# File 'lib/rexml/functions.rb', line 39

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

.false ⇒ Object

UNTESTED



289
290
291
 
# File 'lib/rexml/functions.rb', line 289

def Functions::false(  )
  false
end

.floor(number) ⇒ Object 



357
358
359
 
# File 'lib/rexml/functions.rb', line 357

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

.get_namespace(node_set = nil) ⇒ Object

Helper method.



66
67
68
69
70
71
72
73
74
75
76
 
# File 'lib/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.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) ⇒ Object

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



45
46
 
# File 'lib/rexml/functions.rb', line 45

def Functions::id( object )
end

.lang(language) ⇒ Object

UNTESTED



294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
 
# File 'lib/rexml/functions.rb', line 294

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 ⇒ Object 



31
32
33
 
# File 'lib/rexml/functions.rb', line 31

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

.local_name(node_set = nil) ⇒ Object

UNTESTED



49
50
51
52
53
 
# File 'lib/rexml/functions.rb', line 49

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

.method_missing(id) ⇒ Object 



377
378
379
380
 
# File 'lib/rexml/functions.rb', line 377

def Functions::method_missing( id )
  puts "METHOD MISSING #{id.id2name}"
  XPath.match( @@context[:node], id.id2name )
end

.name(node_set = nil) ⇒ Object 



59
60
61
62
63
 
# File 'lib/rexml/functions.rb', line 59

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

.namespace_context ⇒ Object 



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

def Functions::namespace_context ; @@namespace_context ; end

.namespace_context=(x) ⇒ Object 



14
 
# File 'lib/rexml/functions.rb', line 14

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

.namespace_uri(node_set = nil) ⇒ Object 



55
56
57
 
# File 'lib/rexml/functions.rb', line 55

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

.normalize_space(string = nil) ⇒ Object

UNTESTED



218
219
220
221
222
223
224
225
 
# File 'lib/rexml/functions.rb', line 218

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) ⇒ Object

UNTESTED



279
280
281
 
# File 'lib/rexml/functions.rb', line 279

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

.number(object = nil) ⇒ Object

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



329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
 
# File 'lib/rexml/functions.rb', line 329

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 ⇒ Object 



35
36
37
 
# File 'lib/rexml/functions.rb', line 35

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

.processing_instruction(node) ⇒ Object 



373
374
375
 
# File 'lib/rexml/functions.rb', line 373

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

.round(number) ⇒ Object 



365
366
367
368
369
370
371
 
# File 'lib/rexml/functions.rb', line 365

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

.starts_with(string, test) ⇒ Object

Fixed by Mike Stok



150
151
152
 
# File 'lib/rexml/functions.rb', line 150

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

.string(object = nil) ⇒ Object

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.



113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
 
# File 'lib/rexml/functions.rb', line 113

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) ⇒ Object

UNTESTED



213
214
215
 
# File 'lib/rexml/functions.rb', line 213

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

.string_value(o) ⇒ Object 



132
133
134
135
136
137
138
139
140
141
142
 
# File 'lib/rexml/functions.rb', line 132

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) ⇒ Object

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



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
 
# File 'lib/rexml/functions.rb', line 180

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) ⇒ Object

Kouhei fixed this too



171
172
173
174
175
176
 
# File 'lib/rexml/functions.rb', line 171

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

.substring_before(string, test) ⇒ Object

Kouhei fixed this



160
161
162
163
164
165
166
167
168
 
# File 'lib/rexml/functions.rb', line 160

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) ⇒ Object 



352
353
354
355
 
# File 'lib/rexml/functions.rb', line 352

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

.text ⇒ Object 



21
22
23
24
25
26
27
28
29
 
# File 'lib/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

.translate(string, tr1, tr2) ⇒ Object

This is entirely Mike Stok's beast



228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
 
# File 'lib/rexml/functions.rb', line 228

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

.true ⇒ Object

UNTESTED



284
285
286
 
# File 'lib/rexml/functions.rb', line 284

def Functions::true( )
  true
end

.variables ⇒ Object 



17
 
# File 'lib/rexml/functions.rb', line 17

def Functions::variables ; @@variables ; end

.variables=(x) ⇒ Object 



15
 
# File 'lib/rexml/functions.rb', line 15

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