lib/rexml/validation/relaxng.rb

   1 require "rexml/validation/validation"
   2 require "rexml/parsers/baseparser"
   3
   4 module REXML
   5   module Validation
   6     # Implemented:
   7     # * empty
   8     # * element
   9     # * attribute
  10     # * text
  11     # * optional
  12     # * choice
  13     # * oneOrMore
  14     # * zeroOrMore
  15     # * group
  16     # * value
  17     # * interleave
  18     # * mixed
  19     # * ref
  20     # * grammar
  21     # * start
  22     # * define
  23     #
  24     # Not implemented:
  25     # * data
  26     # * param
  27     # * include
  28     # * externalRef
  29     # * notAllowed
  30     # * anyName
  31     # * nsName
  32     # * except
  33     # * name
  34     class RelaxNG
  35       include Validator
  36
  37       INFINITY = 1.0 / 0.0
  38       EMPTY = Event.new( nil )
  39       TEXT = [:start_element, "text"]
  40       attr_accessor :current
  41       attr_accessor :count
  42       attr_reader :references
  43
  44       # FIXME: Namespaces
  45       def initialize source
  46         parser = REXML::Parsers::BaseParser.new( source )
  47
  48         @count = 0
  49         @references = {}
  50         @root = @current = Sequence.new(self)
  51         @root.previous = true
  52         states = [ @current ]
  53         begin
  54           event = parser.pull
  55           case event[0]
  56           when :start_element
  57             case event[1]
  58             when "empty"
  59             when "element", "attribute", "text", "value"
  60               states[-1] << event
  61             when "optional"
  62               states << Optional.new( self )
  63               states[-2] << states[-1]
  64             when "choice"
  65               states << Choice.new( self )
  66               states[-2] << states[-1]
  67             when "oneOrMore"
  68               states << OneOrMore.new( self )
  69               states[-2] << states[-1]
  70             when "zeroOrMore"
  71               states << ZeroOrMore.new( self )
  72               states[-2] << states[-1]
  73             when "group"
  74               states << Sequence.new( self )
  75               states[-2] << states[-1]
  76             when "interleave"
  77               states << Interleave.new( self )
  78               states[-2] << states[-1]
  79             when "mixed"
  80               states << Interleave.new( self )
  81               states[-2] << states[-1]
  82               states[-1] << TEXT
  83             when "define"
  84               states << [ event[2]["name"] ]
  85             when "ref"
  86               states[-1] << Ref.new( event[2]["name"] )
  87             when "anyName"
  88               states << AnyName.new( self )
  89               states[-2] << states[-1]
  90             when "nsName"
  91             when "except"
  92             when "name"
  93             when "data"
  94             when "param"
  95             when "include"
  96             when "grammar"
  97             when "start"
  98             when "externalRef"
  99             when "notAllowed"
 100             end
 101           when :end_element
 102             case event[1]
 103             when "element", "attribute"
 104               states[-1] << event
 105             when "zeroOrMore", "oneOrMore", "choice", "optional",
 106               "interleave", "group", "mixed"
 107               states.pop
 108             when "define"
 109               ref = states.pop
 110               @references[ ref.shift ] = ref
 111             #when "empty"
 112             end
 113           when :end_document
 114             states[-1] << event
 115           when :text
 116             states[-1] << event
 117           end
 118         end while event[0] != :end_document
 119       end
 120
 121       def receive event
 122         validate( event )
 123       end
 124     end
 125
 126     class State
 127       def initialize( context )
 128         @previous = []
 129         @events = []
 130         @current = 0
 131         @count = context.count += 1
 132         @references = context.references
 133         @value = false
 134       end
 135
 136       def reset
 137         return if @current == 0
 138         @current = 0
 139         @events.each {|s| s.reset if s.kind_of? State }
 140       end
 141
 142       def previous=( previous )
 143         @previous << previous
 144       end
 145
 146       def next( event )
 147         #print "In next with #{event.inspect}.  "
 148         #puts "Next (#@current) is #{@events[@current]}"
 149         #p @previous
 150         return @previous.pop.next( event ) if @events[@current].nil?
 151         expand_ref_in( @events, @current ) if @events[@current].class == Ref
 152         if ( @events[@current].kind_of? State )
 153           @current += 1
 154           @events[@current-1].previous = self
 155           return @events[@current-1].next( event )
 156         end
 157         #puts "Current isn't a state"
 158         if ( @events[@current].matches?(event) )
 159           @current += 1
 160           if @events[@current].nil?
 161             #puts "#{inspect[0,5]} 1RETURNING #{@previous.inspect[0,5]}"
 162             return @previous.pop
 163           elsif @events[@current].kind_of? State
 164             @current += 1
 165             #puts "#{inspect[0,5]} 2RETURNING (#{@current-1}) #{@events[@current-1].inspect[0,5]}; on return, next is #{@events[@current]}"
 166             @events[@current-1].previous = self
 167             return @events[@current-1]
 168           else
 169             #puts "#{inspect[0,5]} RETURNING self w/ next(#@current) = #{@events[@current]}"
 170             return self
 171           end
 172         else
 173           return nil
 174         end
 175       end
 176
 177       def to_s
 178         # Abbreviated:
 179         self.class.name =~ /(?:::)(\w)\w+$/
 180         # Full:
 181         #self.class.name =~ /(?:::)(\w+)$/
 182         "#$1.#@count"
 183       end
 184
 185       def inspect
 186         "< #{to_s} #{@events.collect{|e|
 187           pre = e == @events[@current] ? '#' : ''
 188           pre + e.inspect unless self == e
 189         }.join(', ')} >"
 190       end
 191
 192       def expected
 193         return [@events[@current]]
 194       end
 195
 196       def <<( event )
 197         add_event_to_arry( @events, event )
 198       end
 199
 200
 201       protected
 202       def expand_ref_in( arry, ind )
 203         new_events = []
 204         @references[ arry[ind].to_s ].each{ |evt|
 205           add_event_to_arry(new_events,evt)
 206         }
 207         arry[ind,1] = new_events
 208       end
 209
 210       def add_event_to_arry( arry, evt )
 211         evt = generate_event( evt )
 212         if evt.kind_of? String
 213           arry[-1].event_arg = evt if arry[-1].kind_of? Event and @value
 214           @value = false
 215         else
 216           arry << evt
 217         end
 218       end
 219
 220       def generate_event( event )
 221         return event if event.kind_of? State or event.class == Ref
 222         evt = nil
 223         arg = nil
 224         case event[0]
 225         when :start_element
 226           case event[1]
 227           when "element"
 228             evt = :start_element
 229             arg = event[2]["name"]
 230           when "attribute"
 231             evt = :start_attribute
 232             arg = event[2]["name"]
 233           when "text"
 234             evt = :text
 235           when "value"
 236             evt = :text
 237             @value = true
 238           end
 239         when :text
 240           return event[1]
 241         when :end_document
 242           return Event.new( event[0] )
 243         else # then :end_element
 244           case event[1]
 245           when "element"
 246             evt = :end_element
 247           when "attribute"
 248             evt = :end_attribute
 249           end
 250         end
 251         return Event.new( evt, arg )
 252       end
 253     end
 254
 255
 256     class Sequence < State
 257       def matches?(event)
 258         @events[@current].matches?( event )
 259       end
 260     end
 261
 262
 263     class Optional < State
 264       def next( event )
 265         if @current == 0
 266           rv = super
 267           return rv if rv
 268           @prior = @previous.pop
 269           return @prior.next( event )
 270         end
 271         super
 272       end
 273
 274       def matches?(event)
 275         @events[@current].matches?(event) ||
 276         (@current == 0 and @previous[-1].matches?(event))
 277       end
 278
 279       def expected
 280         return [ @prior.expected, @events[0] ].flatten if @current == 0
 281         return [@events[@current]]
 282       end
 283     end
 284
 285
 286     class ZeroOrMore < Optional
 287       def next( event )
 288         expand_ref_in( @events, @current ) if @events[@current].class == Ref
 289         if ( @events[@current].matches?(event) )
 290           @current += 1
 291           if @events[@current].nil?
 292             @current = 0
 293             return self
 294           elsif @events[@current].kind_of? State
 295             @current += 1
 296             @events[@current-1].previous = self
 297             return @events[@current-1]
 298           else
 299             return self
 300           end
 301         else
 302           @prior = @previous.pop
 303           return @prior.next( event ) if @current == 0
 304           return nil
 305         end
 306       end
 307
 308       def expected
 309         return [ @prior.expected, @events[0] ].flatten if @current == 0
 310         return [@events[@current]]
 311       end
 312     end
 313
 314
 315     class OneOrMore < State
 316       def initialize context
 317         super
 318         @ord = 0
 319       end
 320
 321       def reset
 322         super
 323         @ord = 0
 324       end
 325
 326       def next( event )
 327         expand_ref_in( @events, @current ) if @events[@current].class == Ref
 328         if ( @events[@current].matches?(event) )
 329           @current += 1
 330           @ord += 1
 331           if @events[@current].nil?
 332             @current = 0
 333             return self
 334           elsif @events[@current].kind_of? State
 335             @current += 1
 336             @events[@current-1].previous = self
 337             return @events[@current-1]
 338           else
 339             return self
 340           end
 341         else
 342           return @previous.pop.next( event ) if @current == 0 and @ord > 0
 343           return nil
 344         end
 345       end
 346
 347       def matches?( event )
 348         @events[@current].matches?(event) ||
 349         (@current == 0 and @ord > 0 and @previous[-1].matches?(event))
 350       end
 351
 352       def expected
 353         if @current == 0 and @ord > 0
 354           return [@previous[-1].expected, @events[0]].flatten
 355         else
 356           return [@events[@current]]
 357         end
 358       end
 359     end
 360
 361
 362     class Choice < State
 363       def initialize context
 364         super
 365         @choices = []
 366       end
 367
 368       def reset
 369         super
 370         @events = []
 371         @choices.each { |c| c.each { |s| s.reset if s.kind_of? State } }
 372       end
 373
 374       def <<( event )
 375         add_event_to_arry( @choices, event )
 376       end
 377
 378       def next( event )
 379         # Make the choice if we haven't
 380         if @events.size == 0
 381           c = 0 ; max = @choices.size
 382           while c < max
 383             if @choices[c][0].class == Ref
 384               expand_ref_in( @choices[c], 0 )
 385               @choices += @choices[c]
 386               @choices.delete( @choices[c] )
 387               max -= 1
 388             else
 389               c += 1
 390             end
 391           end
 392           @events = @choices.find { |evt| evt[0].matches? event }
 393           # Remove the references
 394           # Find the events
 395         end
 396         #puts "In next with #{event.inspect}."
 397         #puts "events is #{@events.inspect}"
 398         unless @events
 399           @events = []
 400           return nil
 401         end
 402         #puts "current = #@current"
 403         super
 404       end
 405
 406       def matches?( event )
 407         return @events[@current].matches?( event ) if @events.size > 0
 408         !@choices.find{|evt| evt[0].matches?(event)}.nil?
 409       end
 410
 411       def expected
 412         #puts "IN CHOICE EXPECTED"
 413         #puts "EVENTS = #{@events.inspect}"
 414         return [@events[@current]] if @events.size > 0
 415         return @choices.collect do |x|
 416           if x[0].kind_of? State
 417             x[0].expected
 418           else
 419             x[0]
 420           end
 421         end.flatten
 422       end
 423
 424       def inspect
 425         "< #{to_s} #{@choices.collect{|e| e.collect{|f|f.to_s}.join(', ')}.join(' or ')} >"
 426       end
 427
 428       protected
 429       def add_event_to_arry( arry, evt )
 430         if evt.kind_of? State or evt.class == Ref
 431           arry << [evt]
 432         elsif evt[0] == :text
 433          if arry[-1] and
 434             arry[-1][-1].kind_of?( Event ) and
 435             arry[-1][-1].event_type == :text and @value
 436
 437             arry[-1][-1].event_arg = evt[1]
 438             @value = false
 439           end
 440         else
 441           arry << [] if evt[0] == :start_element
 442           arry[-1] << generate_event( evt )
 443         end
 444       end
 445     end
 446
 447
 448     class Interleave < Choice
 449       def initialize context
 450         super
 451         @choice = 0
 452       end
 453
 454       def reset
 455         @choice = 0
 456       end
 457
 458       def next_current( event )
 459         # Expand references
 460         c = 0 ; max = @choices.size
 461         while c < max
 462           if @choices[c][0].class == Ref
 463             expand_ref_in( @choices[c], 0 )
 464             @choices += @choices[c]
 465             @choices.delete( @choices[c] )
 466             max -= 1
 467           else
 468             c += 1
 469           end
 470         end
 471         @events = @choices[@choice..-1].find { |evt| evt[0].matches? event }
 472         @current = 0
 473         if @events
 474           # reorder the choices
 475           old = @choices[@choice]
 476           idx = @choices.index( @events )
 477           @choices[@choice] = @events
 478           @choices[idx] = old
 479           @choice += 1
 480         end
 481
 482        #puts "In next with #{event.inspect}."
 483        #puts "events is #{@events.inspect}"
 484         @events = [] unless @events
 485       end
 486
 487
 488       def next( event )
 489         # Find the next series
 490         next_current(event) unless @events[@current]
 491         return nil unless @events[@current]
 492
 493         expand_ref_in( @events, @current ) if @events[@current].class == Ref
 494        #puts "In next with #{event.inspect}."
 495        #puts "Next (#@current) is #{@events[@current]}"
 496         if ( @events[@current].kind_of? State )
 497           @current += 1
 498           @events[@current-1].previous = self
 499           return @events[@current-1].next( event )
 500         end
 501        #puts "Current isn't a state"
 502         return @previous.pop.next( event ) if @events[@current].nil?
 503         if ( @events[@current].matches?(event) )
 504           @current += 1
 505           if @events[@current].nil?
 506            #puts "#{inspect[0,5]} 1RETURNING self" unless @choices[@choice].nil?
 507             return self unless @choices[@choice].nil?
 508            #puts "#{inspect[0,5]} 1RETURNING #{@previous[-1].inspect[0,5]}"
 509             return @previous.pop
 510           elsif @events[@current].kind_of? State
 511             @current += 1
 512            #puts "#{inspect[0,5]} 2RETURNING (#{@current-1}) #{@events[@current-1].inspect[0,5]}; on return, next is #{@events[@current]}"
 513             @events[@current-1].previous = self
 514             return @events[@current-1]
 515           else
 516            #puts "#{inspect[0,5]} RETURNING self w/ next(#@current) = #{@events[@current]}"
 517             return self
 518           end
 519         else
 520           return nil
 521         end
 522       end
 523
 524       def matches?( event )
 525         return @events[@current].matches?( event ) if @events[@current]
 526         !@choices[@choice..-1].find{|evt| evt[0].matches?(event)}.nil?
 527       end
 528
 529       def expected
 530         #puts "IN CHOICE EXPECTED"
 531         #puts "EVENTS = #{@events.inspect}"
 532         return [@events[@current]] if @events[@current]
 533         return @choices[@choice..-1].collect do |x|
 534           if x[0].kind_of? State
 535             x[0].expected
 536           else
 537             x[0]
 538           end
 539         end.flatten
 540       end
 541
 542       def inspect
 543         "< #{to_s} #{@choices.collect{|e| e.collect{|f|f.to_s}.join(', ')}.join(' and ')} >"
 544       end
 545     end
 546
 547     class Ref
 548       def initialize value
 549         @value = value
 550       end
 551       def to_s
 552         @value
 553       end
 554       def inspect
 555         "{#{to_s}}"
 556       end
 557     end
 558   end
 559 end