This file is indexed.

/usr/lib/ruby/vendor_ruby/action_view/helpers/prototype_helper.rb is in ruby-actionpack-2.3 2.3.14-5.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 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
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 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
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
require 'set'
require 'active_support/json'

module ActionView
  module Helpers
    # Prototype[http://www.prototypejs.org/] is a JavaScript library that provides
    # DOM[http://en.wikipedia.org/wiki/Document_Object_Model] manipulation,
    # Ajax[http://www.adaptivepath.com/publications/essays/archives/000385.php]
    # functionality, and more traditional object-oriented facilities for JavaScript.
    # This module provides a set of helpers to make it more convenient to call
    # functions from Prototype using Rails, including functionality to call remote
    # Rails methods (that is, making a background request to a Rails action) using Ajax.
    # This means that you can call actions in your controllers without
    # reloading the page, but still update certain parts of it using
    # injections into the DOM. A common use case is having a form that adds
    # a new element to a list without reloading the page or updating a shopping
    # cart total when a new item is added.
    #
    # == Usage
    # To be able to use these helpers, you must first include the Prototype
    # JavaScript framework in your pages.
    #
    #  javascript_include_tag 'prototype'
    #
    # (See the documentation for
    # ActionView::Helpers::JavaScriptHelper for more information on including
    # this and other JavaScript files in your Rails templates.)
    #
    # Now you're ready to call a remote action either through a link...
    #
    #  link_to_remote "Add to cart",
    #    :url => { :action => "add", :id => product.id },
    #    :update => { :success => "cart", :failure => "error" }
    #
    # ...through a form...
    #
    #  <% form_remote_tag :url => '/shipping' do -%>
    #    <div><%= submit_tag 'Recalculate Shipping' %></div>
    #  <% end -%>
    #
    # ...periodically...
    #
    #  periodically_call_remote(:url => 'update', :frequency => '5', :update => 'ticker')
    #
    # ...or through an observer (i.e., a form or field that is observed and calls a remote
    # action when changed).
    #
    #  <%= observe_field(:searchbox,
    #       :url => { :action => :live_search }),
    #       :frequency => 0.5,
    #       :update => :hits,
    #       :with => 'query'
    #       %>
    #
    # As you can see, there are numerous ways to use Prototype's Ajax functions (and actually more than
    # are listed here); check out the documentation for each method to find out more about its usage and options.
    #
    # === Common Options
    # See link_to_remote for documentation of options common to all Ajax
    # helpers; any of the options specified by link_to_remote can be used
    # by the other helpers.
    #
    # == Designing your Rails actions for Ajax
    # When building your action handlers (that is, the Rails actions that receive your background requests), it's
    # important to remember a few things.  First, whatever your action would normally return to the browser, it will
    # return to the Ajax call.  As such, you typically don't want to render with a layout.  This call will cause
    # the layout to be transmitted back to your page, and, if you have a full HTML/CSS, will likely mess a lot of things up.
    # You can turn the layout off on particular actions by doing the following:
    #
    #  class SiteController < ActionController::Base
    #    layout "standard", :except => [:ajax_method, :more_ajax, :another_ajax]
    #  end
    #
    # Optionally, you could do this in the method you wish to lack a layout:
    #
    #  render :layout => false
    #
    # You can tell the type of request from within your action using the <tt>request.xhr?</tt> (XmlHttpRequest, the
    # method that Ajax uses to make background requests) method.
    #  def name
    #    # Is this an XmlHttpRequest request?
    #    if (request.xhr?)
    #      render :text => @name.to_s
    #    else
    #      # No?  Then render an action.
    #      render :action => 'view_attribute', :attr => @name
    #    end
    #  end
    #
    # The else clause can be left off and the current action will render with full layout and template. An extension
    # to this solution was posted to Ryan Heneise's blog at ArtOfMission["http://www.artofmission.com/"].
    #
    #  layout proc{ |c| c.request.xhr? ? false : "application" }
    #
    # Dropping this in your ApplicationController turns the layout off for every request that is an "xhr" request.
    #
    # If you are just returning a little data or don't want to build a template for your output, you may opt to simply
    # render text output, like this:
    #
    #  render :text => 'Return this from my method!'
    #
    # Since whatever the method returns is injected into the DOM, this will simply inject some text (or HTML, if you
    # tell it to).  This is usually how small updates, such updating a cart total or a file count, are handled.
    #
    # == Updating multiple elements
    # See JavaScriptGenerator for information on updating multiple elements
    # on the page in an Ajax response.
    module PrototypeHelper
      unless const_defined? :CALLBACKS
        CALLBACKS    = Set.new([ :create, :uninitialized, :loading, :loaded,
                         :interactive, :complete, :failure, :success ] +
                         (100..599).to_a)
        AJAX_OPTIONS = Set.new([ :before, :after, :condition, :url,
                         :asynchronous, :method, :insertion, :position,
                         :form, :with, :update, :script, :type ]).merge(CALLBACKS)
      end

      # Returns a link to a remote action defined by <tt>options[:url]</tt>
      # (using the url_for format) that's called in the background using
      # XMLHttpRequest. The result of that request can then be inserted into a
      # DOM object whose id can be specified with <tt>options[:update]</tt>.
      # Usually, the result would be a partial prepared by the controller with
      # render :partial.
      #
      # Examples:
      #   # Generates: <a href="#" onclick="new Ajax.Updater('posts', '/blog/destroy/3', {asynchronous:true, evalScripts:true});
      #   #            return false;">Delete this post</a>
      #   link_to_remote "Delete this post", :update => "posts",
      #     :url => { :action => "destroy", :id => post.id }
      #
      #   # Generates: <a href="#" onclick="new Ajax.Updater('emails', '/mail/list_emails', {asynchronous:true, evalScripts:true});
      #   #            return false;"><img alt="Refresh" src="/images/refresh.png?" /></a>
      #   link_to_remote(image_tag("refresh"), :update => "emails",
      #     :url => { :action => "list_emails" })
      #
      # You can override the generated HTML options by specifying a hash in
      # <tt>options[:html]</tt>.
      #
      #   link_to_remote "Delete this post", :update => "posts",
      #     :url  => post_url(@post), :method => :delete,
      #     :html => { :class  => "destructive" }
      #
      # You can also specify a hash for <tt>options[:update]</tt> to allow for
      # easy redirection of output to an other DOM element if a server-side
      # error occurs:
      #
      # Example:
      #   # Generates: <a href="#" onclick="new Ajax.Updater({success:'posts',failure:'error'}, '/blog/destroy/5',
      #   #            {asynchronous:true, evalScripts:true}); return false;">Delete this post</a>
      #   link_to_remote "Delete this post",
      #     :url => { :action => "destroy", :id => post.id },
      #     :update => { :success => "posts", :failure => "error" }
      #
      # Optionally, you can use the <tt>options[:position]</tt> parameter to
      # influence how the target DOM element is updated. It must be one of
      # <tt>:before</tt>, <tt>:top</tt>, <tt>:bottom</tt>, or <tt>:after</tt>.
      #
      # The method used is by default POST. You can also specify GET or you
      # can simulate PUT or DELETE over POST. All specified with <tt>options[:method]</tt>
      #
      # Example:
      #   # Generates: <a href="#" onclick="new Ajax.Request('/person/4', {asynchronous:true, evalScripts:true, method:'delete'});
      #   #            return false;">Destroy</a>
      #   link_to_remote "Destroy", :url => person_url(:id => person), :method => :delete
      #
      # By default, these remote requests are processed asynchronous during
      # which various JavaScript callbacks can be triggered (for progress
      # indicators and the likes). All callbacks get access to the
      # <tt>request</tt> object, which holds the underlying XMLHttpRequest.
      #
      # To access the server response, use <tt>request.responseText</tt>, to
      # find out the HTTP status, use <tt>request.status</tt>.
      #
      # Example:
      #   # Generates: <a href="#" onclick="new Ajax.Request('/words/undo?n=33', {asynchronous:true, evalScripts:true,
      #   #            onComplete:function(request){undoRequestCompleted(request)}}); return false;">hello</a>
      #   word = 'hello'
      #   link_to_remote word,
      #     :url => { :action => "undo", :n => word_counter },
      #     :complete => "undoRequestCompleted(request)"
      #
      # The callbacks that may be specified are (in order):
      #
      # <tt>:loading</tt>::       Called when the remote document is being
      #                           loaded with data by the browser.
      # <tt>:loaded</tt>::        Called when the browser has finished loading
      #                           the remote document.
      # <tt>:interactive</tt>::   Called when the user can interact with the
      #                           remote document, even though it has not
      #                           finished loading.
      # <tt>:success</tt>::       Called when the XMLHttpRequest is completed,
      #                           and the HTTP status code is in the 2XX range.
      # <tt>:failure</tt>::       Called when the XMLHttpRequest is completed,
      #                           and the HTTP status code is not in the 2XX
      #                           range.
      # <tt>:complete</tt>::      Called when the XMLHttpRequest is complete
      #                           (fires after success/failure if they are
      #                           present).
      #
      # You can further refine <tt>:success</tt> and <tt>:failure</tt> by
      # adding additional callbacks for specific status codes.
      #
      # Example:
      #   # Generates: <a href="#" onclick="new Ajax.Request('/testing/action', {asynchronous:true, evalScripts:true,
      #   #            on404:function(request){alert('Not found...? Wrong URL...?')},
      #   #            onFailure:function(request){alert('HTTP Error ' + request.status + '!')}}); return false;">hello</a>
      #   link_to_remote word,
      #     :url => { :action => "action" },
      #     404 => "alert('Not found...? Wrong URL...?')",
      #     :failure => "alert('HTTP Error ' + request.status + '!')"
      #
      # A status code callback overrides the success/failure handlers if
      # present.
      #
      # If you for some reason or another need synchronous processing (that'll
      # block the browser while the request is happening), you can specify
      # <tt>options[:type] = :synchronous</tt>.
      #
      # You can customize further browser side call logic by passing in
      # JavaScript code snippets via some optional parameters. In their order
      # of use these are:
      #
      # <tt>:confirm</tt>::      Adds confirmation dialog.
      # <tt>:condition</tt>::    Perform remote request conditionally
      #                          by this expression. Use this to
      #                          describe browser-side conditions when
      #                          request should not be initiated.
      # <tt>:before</tt>::       Called before request is initiated.
      # <tt>:after</tt>::        Called immediately after request was
      #                          initiated and before <tt>:loading</tt>.
      # <tt>:submit</tt>::       Specifies the DOM element ID that's used
      #                          as the parent of the form elements. By
      #                          default this is the current form, but
      #                          it could just as well be the ID of a
      #                          table row or any other DOM element.
      # <tt>:with</tt>::         A JavaScript expression specifying
      #                          the parameters for the XMLHttpRequest.
      #                          Any expressions should return a valid
      #                          URL query string.
      #
      #                          Example:
      #
      #                            :with => "'name=' + $('name').value"
      #
      # You can generate a link that uses AJAX in the general case, while
      # degrading gracefully to plain link behavior in the absence of
      # JavaScript by setting <tt>html_options[:href]</tt> to an alternate URL.
      # Note the extra curly braces around the <tt>options</tt> hash separate
      # it as the second parameter from <tt>html_options</tt>, the third.
      #
      # Example:
      #   link_to_remote "Delete this post",
      #     { :update => "posts", :url => { :action => "destroy", :id => post.id } },
      #     :href => url_for(:action => "destroy", :id => post.id)
      def link_to_remote(name, options = {}, html_options = nil)
        link_to_function(name, remote_function(options), html_options || options.delete(:html))
      end

      # Creates a button with an onclick event which calls a remote action
      # via XMLHttpRequest
      # The options for specifying the target with :url
      # and defining callbacks is the same as link_to_remote.
      def button_to_remote(name, options = {}, html_options = {})
        button_to_function(name, remote_function(options), html_options)
      end

      # Periodically calls the specified url (<tt>options[:url]</tt>) every
      # <tt>options[:frequency]</tt> seconds (default is 10). Usually used to
      # update a specified div (<tt>options[:update]</tt>) with the results
      # of the remote call. The options for specifying the target with <tt>:url</tt>
      # and defining callbacks is the same as link_to_remote.
      # Examples:
      #  # Call get_averages and put its results in 'avg' every 10 seconds
      #  # Generates:
      #  #      new PeriodicalExecuter(function() {new Ajax.Updater('avg', '/grades/get_averages',
      #  #      {asynchronous:true, evalScripts:true})}, 10)
      #  periodically_call_remote(:url => { :action => 'get_averages' }, :update => 'avg')
      #
      #  # Call invoice every 10 seconds with the id of the customer
      #  # If it succeeds, update the invoice DIV; if it fails, update the error DIV
      #  # Generates:
      #  #      new PeriodicalExecuter(function() {new Ajax.Updater({success:'invoice',failure:'error'},
      #  #      '/testing/invoice/16', {asynchronous:true, evalScripts:true})}, 10)
      #  periodically_call_remote(:url => { :action => 'invoice', :id => customer.id },
      #     :update => { :success => "invoice", :failure => "error" }
      #
      #  # Call update every 20 seconds and update the new_block DIV
      #  # Generates:
      #  # new PeriodicalExecuter(function() {new Ajax.Updater('news_block', 'update', {asynchronous:true, evalScripts:true})}, 20)
      #  periodically_call_remote(:url => 'update', :frequency => '20', :update => 'news_block')
      #
      def periodically_call_remote(options = {})
         frequency = options[:frequency] || 10 # every ten seconds by default
         code = "new PeriodicalExecuter(function() {#{remote_function(options)}}, #{frequency})"
         javascript_tag(code)
      end

      # Returns a form tag that will submit using XMLHttpRequest in the
      # background instead of the regular reloading POST arrangement. Even
      # though it's using JavaScript to serialize the form elements, the form
      # submission will work just like a regular submission as viewed by the
      # receiving side (all elements available in <tt>params</tt>). The options for
      # specifying the target with <tt>:url</tt> and defining callbacks is the same as
      # +link_to_remote+.
      #
      # A "fall-through" target for browsers that doesn't do JavaScript can be
      # specified with the <tt>:action</tt>/<tt>:method</tt> options on <tt>:html</tt>.
      #
      # Example:
      #   # Generates:
      #   #      <form action="/some/place" method="post" onsubmit="new Ajax.Request('',
      #   #      {asynchronous:true, evalScripts:true, parameters:Form.serialize(this)}); return false;">
      #   form_remote_tag :html => { :action =>
      #     url_for(:controller => "some", :action => "place") }
      #
      # The Hash passed to the <tt>:html</tt> key is equivalent to the options (2nd)
      # argument in the FormTagHelper.form_tag method.
      #
      # By default the fall-through action is the same as the one specified in
      # the <tt>:url</tt> (and the default method is <tt>:post</tt>).
      #
      # form_remote_tag also takes a block, like form_tag:
      #   # Generates:
      #   #     <form action="/" method="post" onsubmit="new Ajax.Request('/',
      #   #     {asynchronous:true, evalScripts:true, parameters:Form.serialize(this)});
      #   #     return false;"> <div><input name="commit" type="submit" value="Save" /></div>
      #   #     </form>
      #   <% form_remote_tag :url => '/posts' do -%>
      #     <div><%= submit_tag 'Save' %></div>
      #   <% end -%>
      def form_remote_tag(options = {}, &block)
        options[:form] = true

        options[:html] ||= {}
        options[:html][:onsubmit] =
          (options[:html][:onsubmit] ? options[:html][:onsubmit] + "; " : "") +
          "#{remote_function(options)}; return false;"

        form_tag(options[:html].delete(:action) || url_for(options[:url]), options[:html], &block)
      end

      # Creates a form that will submit using XMLHttpRequest in the background
      # instead of the regular reloading POST arrangement and a scope around a
      # specific resource that is used as a base for questioning about
      # values for the fields.
      #
      # === Resource
      #
      # Example:
      #   <% remote_form_for(@post) do |f| %>
      #     ...
      #   <% end %>
      #
      # This will expand to be the same as:
      #
      #   <% remote_form_for :post, @post, :url => post_path(@post), :html => { :method => :put, :class => "edit_post", :id => "edit_post_45" } do |f| %>
      #     ...
      #   <% end %>
      #
      # === Nested Resource
      #
      # Example:
      #   <% remote_form_for([@post, @comment]) do |f| %>
      #     ...
      #   <% end %>
      #
      # This will expand to be the same as:
      #
      #   <% remote_form_for :comment, @comment, :url => post_comment_path(@post, @comment), :html => { :method => :put, :class => "edit_comment", :id => "edit_comment_45" } do |f| %>
      #     ...
      #   <% end %>
      #
      # If you don't need to attach a form to a resource, then check out form_remote_tag.
      #
      # See FormHelper#form_for for additional semantics.
      def remote_form_for(record_or_name_or_array, *args, &proc)
        options = args.extract_options!

        case record_or_name_or_array
        when String, Symbol
          object_name = record_or_name_or_array
        when Array
          object = record_or_name_or_array.last
          object_name = ActionController::RecordIdentifier.singular_class_name(object)
          apply_form_for_options!(record_or_name_or_array, options)
          args.unshift object
        else
          object      = record_or_name_or_array
          object_name = ActionController::RecordIdentifier.singular_class_name(record_or_name_or_array)
          apply_form_for_options!(object, options)
          args.unshift object
        end

        concat(form_remote_tag(options))
        fields_for(object_name, *(args << options), &proc)
        concat('</form>'.html_safe)
      end
      alias_method :form_remote_for, :remote_form_for

      # Returns a button input tag with the element name of +name+ and a value (i.e., display text) of +value+
      # that will submit form using XMLHttpRequest in the background instead of a regular POST request that
      # reloads the page.
      #
      #  # Create a button that submits to the create action
      #  #
      #  # Generates: <input name="create_btn" onclick="new Ajax.Request('/testing/create',
      #  #     {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)});
      #  #     return false;" type="button" value="Create" />
      #  <%= submit_to_remote 'create_btn', 'Create', :url => { :action => 'create' } %>
      #
      #  # Submit to the remote action update and update the DIV succeed or fail based
      #  # on the success or failure of the request
      #  #
      #  # Generates: <input name="update_btn" onclick="new Ajax.Updater({success:'succeed',failure:'fail'},
      #  #      '/testing/update', {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)});
      #  #      return false;" type="button" value="Update" />
      #  <%= submit_to_remote 'update_btn', 'Update', :url => { :action => 'update' },
      #     :update => { :success => "succeed", :failure => "fail" }
      #
      # <tt>options</tt> argument is the same as in form_remote_tag.
      def submit_to_remote(name, value, options = {})
        options[:with] ||= 'Form.serialize(this.form)'

        html_options = options.delete(:html) || {}
        html_options[:name] = name

        button_to_remote(value, options, html_options)
      end

      # Returns '<tt>eval(request.responseText)</tt>' which is the JavaScript function
      # that +form_remote_tag+ can call in <tt>:complete</tt> to evaluate a multiple
      # update return document using +update_element_function+ calls.
      def evaluate_remote_response
        "eval(request.responseText)"
      end

      # Returns the JavaScript needed for a remote function.
      # Takes the same arguments as link_to_remote.
      #
      # Example:
      #   # Generates: <select id="options" onchange="new Ajax.Updater('options',
      #   # '/testing/update_options', {asynchronous:true, evalScripts:true})">
      #   <select id="options" onchange="<%= remote_function(:update => "options",
      #       :url => { :action => :update_options }) %>">
      #     <option value="0">Hello</option>
      #     <option value="1">World</option>
      #   </select>
      def remote_function(options)
        javascript_options = options_for_ajax(options)

        update = ''
        if options[:update] && options[:update].is_a?(Hash)
          update  = []
          update << "success:'#{options[:update][:success]}'" if options[:update][:success]
          update << "failure:'#{options[:update][:failure]}'" if options[:update][:failure]
          update  = '{' + update.join(',') + '}'
        elsif options[:update]
          update << "'#{options[:update]}'"
        end

        function = update.empty? ?
          "new Ajax.Request(" :
          "new Ajax.Updater(#{update}, "

        url_options = options[:url]
        url_options = url_options.merge(:escape => false) if url_options.is_a?(Hash)
        function << "'#{escape_javascript(url_for(url_options))}'"
        function << ", #{javascript_options})"

        function = "#{options[:before]}; #{function}" if options[:before]
        function = "#{function}; #{options[:after]}"  if options[:after]
        function = "if (#{options[:condition]}) { #{function}; }" if options[:condition]
        function = "if (confirm('#{escape_javascript(options[:confirm])}')) { #{function}; }" if options[:confirm]

        return function
      end

      # Observes the field with the DOM ID specified by +field_id+ and calls a
      # callback when its contents have changed. The default callback is an
      # Ajax call. By default the value of the observed field is sent as a
      # parameter with the Ajax call.
      #
      # Example:
      #  # Generates: new Form.Element.Observer('suggest', 0.25, function(element, value) {new Ajax.Updater('suggest',
      #  #         '/testing/find_suggestion', {asynchronous:true, evalScripts:true, parameters:'q=' + value})})
      #  <%= observe_field :suggest, :url => { :action => :find_suggestion },
      #       :frequency => 0.25,
      #       :update => :suggest,
      #       :with => 'q'
      #       %>
      #
      # Required +options+ are either of:
      # <tt>:url</tt>::       +url_for+-style options for the action to call
      #                       when the field has changed.
      # <tt>:function</tt>::  Instead of making a remote call to a URL, you
      #                       can specify javascript code to be called instead.
      #                       Note that the value of this option is used as the
      #                       *body* of the javascript function, a function definition
      #                       with parameters named element and value will be generated for you
      #                       for example:
      #                         observe_field("glass", :frequency => 1, :function => "alert('Element changed')")
      #                       will generate:
      #                         new Form.Element.Observer('glass', 1, function(element, value) {alert('Element changed')})
      #                       The element parameter is the DOM element being observed, and the value is its value at the
      #                       time the observer is triggered.
      #
      # Additional options are:
      # <tt>:frequency</tt>:: The frequency (in seconds) at which changes to
      #                       this field will be detected. Not setting this
      #                       option at all or to a value equal to or less than
      #                       zero will use event based observation instead of
      #                       time based observation.
      # <tt>:update</tt>::    Specifies the DOM ID of the element whose
      #                       innerHTML should be updated with the
      #                       XMLHttpRequest response text.
      # <tt>:with</tt>::      A JavaScript expression specifying the parameters
      #                       for the XMLHttpRequest. The default is to send the
      #                       key and value of the observed field. Any custom
      #                       expressions should return a valid URL query string.
      #                       The value of the field is stored in the JavaScript
      #                       variable +value+.
      #
      #                       Examples
      #
      #                         :with => "'my_custom_key=' + value"
      #                         :with => "'person[name]=' + prompt('New name')"
      #                         :with => "Form.Element.serialize('other-field')"
      #
      #                       Finally
      #                         :with => 'name'
      #                       is shorthand for
      #                         :with => "'name=' + value"
      #                       This essentially just changes the key of the parameter.
      #
      # Additionally, you may specify any of the options documented in the
      # <em>Common options</em> section at the top of this document.
      #
      # Example:
      #
      #   # Sends params: {:title => 'Title of the book'} when the book_title input
      #   # field is changed.
      #   observe_field 'book_title',
      #     :url => 'http://example.com/books/edit/1',
      #     :with => 'title'
      #
      #
      def observe_field(field_id, options = {})
        if options[:frequency] && options[:frequency] > 0
          build_observer('Form.Element.Observer', field_id, options)
        else
          build_observer('Form.Element.EventObserver', field_id, options)
        end
      end

      # Observes the form with the DOM ID specified by +form_id+ and calls a
      # callback when its contents have changed. The default callback is an
      # Ajax call. By default all fields of the observed field are sent as
      # parameters with the Ajax call.
      #
      # The +options+ for +observe_form+ are the same as the options for
      # +observe_field+. The JavaScript variable +value+ available to the
      # <tt>:with</tt> option is set to the serialized form by default.
      def observe_form(form_id, options = {})
        if options[:frequency]
          build_observer('Form.Observer', form_id, options)
        else
          build_observer('Form.EventObserver', form_id, options)
        end
      end

      # All the methods were moved to GeneratorMethods so that
      # #include_helpers_from_context has nothing to overwrite.
      class JavaScriptGenerator #:nodoc:
        def initialize(context, &block) #:nodoc:
          @context, @lines = context, []
          include_helpers_from_context
          @context.with_output_buffer(@lines) do
            @context.instance_exec(self, &block)
          end
        end

        private
          def include_helpers_from_context
            extend @context.helpers if @context.respond_to?(:helpers)
            extend GeneratorMethods
          end

        # JavaScriptGenerator generates blocks of JavaScript code that allow you
        # to change the content and presentation of multiple DOM elements.  Use
        # this in your Ajax response bodies, either in a <script> tag or as plain
        # JavaScript sent with a Content-type of "text/javascript".
        #
        # Create new instances with PrototypeHelper#update_page or with
        # ActionController::Base#render, then call +insert_html+, +replace_html+,
        # +remove+, +show+, +hide+, +visual_effect+, or any other of the built-in
        # methods on the yielded generator in any order you like to modify the
        # content and appearance of the current page.
        #
        # Example:
        #
        #   # Generates:
        #   #     new Element.insert("list", { bottom: "<li>Some item</li>" });
        #   #     new Effect.Highlight("list");
        #   #     ["status-indicator", "cancel-link"].each(Element.hide);
        #   update_page do |page|
        #     page.insert_html :bottom, 'list', "<li>#{@item.name}</li>"
        #     page.visual_effect :highlight, 'list'
        #     page.hide 'status-indicator', 'cancel-link'
        #   end
        #
        #
        # Helper methods can be used in conjunction with JavaScriptGenerator.
        # When a helper method is called inside an update block on the +page+
        # object, that method will also have access to a +page+ object.
        #
        # Example:
        #
        #   module ApplicationHelper
        #     def update_time
        #       page.replace_html 'time', Time.now.to_s(:db)
        #       page.visual_effect :highlight, 'time'
        #     end
        #   end
        #
        #   # Controller action
        #   def poll
        #     render(:update) { |page| page.update_time }
        #   end
        #
        # Calls to JavaScriptGenerator not matching a helper method below
        # generate a proxy to the JavaScript Class named by the method called.
        #
        # Examples:
        #
        #   # Generates:
        #   #     Foo.init();
        #   update_page do |page|
        #     page.foo.init
        #   end
        #
        #   # Generates:
        #   #     Event.observe('one', 'click', function () {
        #   #       $('two').show();
        #   #     });
        #   update_page do |page|
        #     page.event.observe('one', 'click') do |p|
        #      p[:two].show
        #     end
        #   end
        #
        # You can also use PrototypeHelper#update_page_tag instead of
        # PrototypeHelper#update_page to wrap the generated JavaScript in a
        # <script> tag.
        module GeneratorMethods
          def to_s #:nodoc:
            (@lines * $/).tap do |javascript|
              if ActionView::Base.debug_rjs
                source = javascript.dup
                javascript.replace "try {\n#{source}\n} catch (e) "
                javascript << "{ alert('RJS error:\\n\\n' + e.toString()); alert('#{source.gsub('\\','\0\0').gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }}'); throw e }"
              end
            end
          end

          # Returns a element reference by finding it through +id+ in the DOM. This element can then be
          # used for further method calls. Examples:
          #
          #   page['blank_slate']                  # => $('blank_slate');
          #   page['blank_slate'].show             # => $('blank_slate').show();
          #   page['blank_slate'].show('first').up # => $('blank_slate').show('first').up();
          #
          # You can also pass in a record, which will use ActionController::RecordIdentifier.dom_id to lookup
          # the correct id:
          #
          #   page[@post]     # => $('post_45')
          #   page[Post.new]  # => $('new_post')
          def [](id)
            case id
              when String, Symbol, NilClass
                JavaScriptElementProxy.new(self, id)
              else
                JavaScriptElementProxy.new(self, ActionController::RecordIdentifier.dom_id(id))
            end
          end

          # Returns an object whose <tt>to_json</tt> evaluates to +code+. Use this to pass a literal JavaScript
          # expression as an argument to another JavaScriptGenerator method.
          def literal(code)
            ::ActiveSupport::JSON::Variable.new(code.to_s)
          end

          # Returns a collection reference by finding it through a CSS +pattern+ in the DOM. This collection can then be
          # used for further method calls. Examples:
          #
          #   page.select('p')                      # => $$('p');
          #   page.select('p.welcome b').first      # => $$('p.welcome b').first();
          #   page.select('p.welcome b').first.hide # => $$('p.welcome b').first().hide();
          #
          # You can also use prototype enumerations with the collection.  Observe:
          #
          #   # Generates: $$('#items li').each(function(value) { value.hide(); });
          #   page.select('#items li').each do |value|
          #     value.hide
          #   end
          #
          # Though you can call the block param anything you want, they are always rendered in the
          # javascript as 'value, index.'  Other enumerations, like collect() return the last statement:
          #
          #   # Generates: var hidden = $$('#items li').collect(function(value, index) { return value.hide(); });
          #   page.select('#items li').collect('hidden') do |item|
          #     item.hide
          #   end
          #
          def select(pattern)
            JavaScriptElementCollectionProxy.new(self, pattern)
          end

          # Inserts HTML at the specified +position+ relative to the DOM element
          # identified by the given +id+.
          #
          # +position+ may be one of:
          #
          # <tt>:top</tt>::    HTML is inserted inside the element, before the
          #                    element's existing content.
          # <tt>:bottom</tt>:: HTML is inserted inside the element, after the
          #                    element's existing content.
          # <tt>:before</tt>:: HTML is inserted immediately preceding the element.
          # <tt>:after</tt>::  HTML is inserted immediately following the element.
          #
          # +options_for_render+ may be either a string of HTML to insert, or a hash
          # of options to be passed to ActionView::Base#render.  For example:
          #
          #   # Insert the rendered 'navigation' partial just before the DOM
          #   # element with ID 'content'.
          #   # Generates: Element.insert("content", { before: "-- Contents of 'navigation' partial --" });
          #   page.insert_html :before, 'content', :partial => 'navigation'
          #
          #   # Add a list item to the bottom of the <ul> with ID 'list'.
          #   # Generates: Element.insert("list", { bottom: "<li>Last item</li>" });
          #   page.insert_html :bottom, 'list', '<li>Last item</li>'
          #
          def insert_html(position, id, *options_for_render)
            content = javascript_object_for(render(*options_for_render))
            record "Element.insert(\"#{id}\", { #{position.to_s.downcase}: #{content} });"
          end

          # Replaces the inner HTML of the DOM element with the given +id+.
          #
          # +options_for_render+ may be either a string of HTML to insert, or a hash
          # of options to be passed to ActionView::Base#render.  For example:
          #
          #   # Replace the HTML of the DOM element having ID 'person-45' with the
          #   # 'person' partial for the appropriate object.
          #   # Generates:  Element.update("person-45", "-- Contents of 'person' partial --");
          #   page.replace_html 'person-45', :partial => 'person', :object => @person
          #
          def replace_html(id, *options_for_render)
            call 'Element.update', id, render(*options_for_render)
          end

          # Replaces the "outer HTML" (i.e., the entire element, not just its
          # contents) of the DOM element with the given +id+.
          #
          # +options_for_render+ may be either a string of HTML to insert, or a hash
          # of options to be passed to ActionView::Base#render.  For example:
          #
          #   # Replace the DOM element having ID 'person-45' with the
          #   # 'person' partial for the appropriate object.
          #   page.replace 'person-45', :partial => 'person', :object => @person
          #
          # This allows the same partial that is used for the +insert_html+ to
          # be also used for the input to +replace+ without resorting to
          # the use of wrapper elements.
          #
          # Examples:
          #
          #   <div id="people">
          #     <%= render :partial => 'person', :collection => @people %>
          #   </div>
          #
          #   # Insert a new person
          #   #
          #   # Generates: new Insertion.Bottom({object: "Matz", partial: "person"}, "");
          #   page.insert_html :bottom, :partial => 'person', :object => @person
          #
          #   # Replace an existing person
          #
          #   # Generates: Element.replace("person_45", "-- Contents of partial --");
          #   page.replace 'person_45', :partial => 'person', :object => @person
          #
          def replace(id, *options_for_render)
            call 'Element.replace', id, render(*options_for_render)
          end

          # Removes the DOM elements with the given +ids+ from the page.
          #
          # Example:
          #
          #  # Remove a few people
          #  # Generates: ["person_23", "person_9", "person_2"].each(Element.remove);
          #  page.remove 'person_23', 'person_9', 'person_2'
          #
          def remove(*ids)
            loop_on_multiple_args 'Element.remove', ids
          end

          # Shows hidden DOM elements with the given +ids+.
          #
          # Example:
          #
          #  # Show a few people
          #  # Generates: ["person_6", "person_13", "person_223"].each(Element.show);
          #  page.show 'person_6', 'person_13', 'person_223'
          #
          def show(*ids)
            loop_on_multiple_args 'Element.show', ids
          end

          # Hides the visible DOM elements with the given +ids+.
          #
          # Example:
          #
          #  # Hide a few people
          #  # Generates: ["person_29", "person_9", "person_0"].each(Element.hide);
          #  page.hide 'person_29', 'person_9', 'person_0'
          #
          def hide(*ids)
            loop_on_multiple_args 'Element.hide', ids
          end

          # Toggles the visibility of the DOM elements with the given +ids+.
          # Example:
          #
          #  # Show a few people
          #  # Generates: ["person_14", "person_12", "person_23"].each(Element.toggle);
          #  page.toggle 'person_14', 'person_12', 'person_23'      # Hides the elements
          #  page.toggle 'person_14', 'person_12', 'person_23'      # Shows the previously hidden elements
          #
          def toggle(*ids)
            loop_on_multiple_args 'Element.toggle', ids
          end

          # Displays an alert dialog with the given +message+.
          #
          # Example:
          #
          #   # Generates: alert('This message is from Rails!')
          #   page.alert('This message is from Rails!')
          def alert(message)
            call 'alert', message
          end

          # Redirects the browser to the given +location+ using JavaScript, in the same form as +url_for+.
          #
          # Examples:
          #
          #  # Generates: window.location.href = "/mycontroller";
          #  page.redirect_to(:action => 'index')
          #
          #  # Generates: window.location.href = "/account/signup";
          #  page.redirect_to(:controller => 'account', :action => 'signup')
          def redirect_to(location)
            url = location.is_a?(String) ? location : @context.url_for(location)
            record "window.location.href = #{url.inspect}"
          end

          # Reloads the browser's current +location+ using JavaScript
          #
          # Examples:
          #
          #  # Generates: window.location.reload();
          #  page.reload
          def reload
            record 'window.location.reload()'
          end

          # Calls the JavaScript +function+, optionally with the given +arguments+.
          #
          # If a block is given, the block will be passed to a new JavaScriptGenerator;
          # the resulting JavaScript code will then be wrapped inside <tt>function() { ... }</tt>
          # and passed as the called function's final argument.
          #
          # Examples:
          #
          #   # Generates: Element.replace(my_element, "My content to replace with.")
          #   page.call 'Element.replace', 'my_element', "My content to replace with."
          #
          #   # Generates: alert('My message!')
          #   page.call 'alert', 'My message!'
          #
          #   # Generates:
          #   #     my_method(function() {
          #   #       $("one").show();
          #   #       $("two").hide();
          #   #    });
          #   page.call(:my_method) do |p|
          #      p[:one].show
          #      p[:two].hide
          #   end
          def call(function, *arguments, &block)
            record "#{function}(#{arguments_for_call(arguments, block)})"
          end

          # Assigns the JavaScript +variable+ the given +value+.
          #
          # Examples:
          #
          #  # Generates: my_string = "This is mine!";
          #  page.assign 'my_string', 'This is mine!'
          #
          #  # Generates: record_count = 33;
          #  page.assign 'record_count', 33
          #
          #  # Generates: tabulated_total = 47
          #  page.assign 'tabulated_total', @total_from_cart
          #
          def assign(variable, value)
            record "#{variable} = #{javascript_object_for(value)}"
          end

          # Writes raw JavaScript to the page.
          #
          # Example:
          #
          #  page << "alert('JavaScript with Prototype.');"
          def <<(javascript)
            @lines << javascript
          end

          # Executes the content of the block after a delay of +seconds+. Example:
          #
          #   # Generates:
          #   #     setTimeout(function() {
          #   #     ;
          #   #     new Effect.Fade("notice",{});
          #   #     }, 20000);
          #   page.delay(20) do
          #     page.visual_effect :fade, 'notice'
          #   end
          def delay(seconds = 1)
            record "setTimeout(function() {\n\n"
            yield
            record "}, #{(seconds * 1000).to_i})"
          end

          # Starts a script.aculo.us visual effect. See
          # ActionView::Helpers::ScriptaculousHelper for more information.
          def visual_effect(name, id = nil, options = {})
            record @context.send(:visual_effect, name, id, options)
          end

          # Creates a script.aculo.us sortable element. Useful
          # to recreate sortable elements after items get added
          # or deleted.
          # See ActionView::Helpers::ScriptaculousHelper for more information.
          def sortable(id, options = {})
            record @context.send(:sortable_element_js, id, options)
          end

          # Creates a script.aculo.us draggable element.
          # See ActionView::Helpers::ScriptaculousHelper for more information.
          def draggable(id, options = {})
            record @context.send(:draggable_element_js, id, options)
          end

          # Creates a script.aculo.us drop receiving element.
          # See ActionView::Helpers::ScriptaculousHelper for more information.
          def drop_receiving(id, options = {})
            record @context.send(:drop_receiving_element_js, id, options)
          end

          private
            def loop_on_multiple_args(method, ids)
              record(ids.size>1 ?
                "#{javascript_object_for(ids)}.each(#{method})" :
                "#{method}(#{::ActiveSupport::JSON.encode(ids.first)})")
            end

            def page
              self
            end

            def record(line)
              "#{line.to_s.chomp.gsub(/\;\z/, '')};".tap do |_line|
                self << _line
              end
            end

            def render(*options_for_render)
              old_format = @context && @context.template_format
              @context.template_format = :html if @context
              Hash === options_for_render.first ?
                @context.render(*options_for_render) :
                  options_for_render.first.to_s
            ensure
              @context.template_format = old_format if @context
            end

            def javascript_object_for(object)
              ::ActiveSupport::JSON.encode(object)
            end

            def arguments_for_call(arguments, block = nil)
              arguments << block_to_function(block) if block
              arguments.map { |argument| javascript_object_for(argument) }.join ', '
            end

            def block_to_function(block)
              generator = self.class.new(@context, &block)
              literal("function() { #{generator.to_s} }")
            end

            def method_missing(method, *arguments)
              JavaScriptProxy.new(self, method.to_s.camelize)
            end
        end
      end

      # Yields a JavaScriptGenerator and returns the generated JavaScript code.
      # Use this to update multiple elements on a page in an Ajax response.
      # See JavaScriptGenerator for more information.
      #
      # Example:
      #
      #   update_page do |page|
      #     page.hide 'spinner'
      #   end
      def update_page(&block)
        JavaScriptGenerator.new(@template, &block).to_s.html_safe
      end

      # Works like update_page but wraps the generated JavaScript in a <script>
      # tag. Use this to include generated JavaScript in an ERb template.
      # See JavaScriptGenerator for more information.
      #
      # +html_options+ may be a hash of <script> attributes to be passed
      # to ActionView::Helpers::JavaScriptHelper#javascript_tag.
      def update_page_tag(html_options = {}, &block)
        javascript_tag update_page(&block), html_options
      end

    protected
      def options_for_ajax(options)
        js_options = build_callbacks(options)

        js_options['asynchronous'] = options[:type] != :synchronous
        js_options['method']       = method_option_to_s(options[:method]) if options[:method]
        js_options['insertion']    = "'#{options[:position].to_s.downcase}'" if options[:position]
        js_options['evalScripts']  = options[:script].nil? || options[:script]

        if options[:form]
          js_options['parameters'] = 'Form.serialize(this)'
        elsif options[:submit]
          js_options['parameters'] = "Form.serialize('#{options[:submit]}')"
        elsif options[:with]
          js_options['parameters'] = options[:with]
        end

        if protect_against_forgery? && !options[:form]
          if js_options['parameters']
            js_options['parameters'] << " + '&"
          else
            js_options['parameters'] = "'"
          end
          js_options['parameters'] << "#{request_forgery_protection_token}=' + encodeURIComponent('#{escape_javascript form_authenticity_token}')"
        end

        options_for_javascript(js_options)
      end

      def method_option_to_s(method)
        (method.is_a?(String) and !method.index("'").nil?) ? method : "'#{method}'"
      end

      def build_observer(klass, name, options = {})
        if options[:with] && (options[:with] !~ /[\{=(.]/)
          options[:with] = "'#{options[:with]}=' + encodeURIComponent(value)"
        else
          options[:with] ||= 'value' unless options[:function]
        end

        callback = options[:function] || remote_function(options)
        javascript  = "new #{klass}('#{name}', "
        javascript << "#{options[:frequency]}, " if options[:frequency]
        javascript << "function(element, value) {"
        javascript << "#{callback}}"
        javascript << ")"
        javascript_tag(javascript)
      end

      def build_callbacks(options)
        callbacks = {}
        options.each do |callback, code|
          if CALLBACKS.include?(callback)
            name = 'on' + callback.to_s.capitalize
            callbacks[name] = "function(request){#{code}}"
          end
        end
        callbacks
      end
    end

    # Converts chained method calls on DOM proxy elements into JavaScript chains
    class JavaScriptProxy < ActiveSupport::BasicObject #:nodoc:

      def initialize(generator, root = nil)
        @generator = generator
        @generator << root if root
      end

      private
        def method_missing(method, *arguments, &block)
          if method.to_s =~ /(.*)=$/
            assign($1, arguments.first)
          else
            call("#{method.to_s.camelize(:lower)}", *arguments, &block)
          end
        end

        def call(function, *arguments, &block)
          append_to_function_chain!("#{function}(#{@generator.send(:arguments_for_call, arguments, block)})")
          self
        end

        def assign(variable, value)
          append_to_function_chain!("#{variable} = #{@generator.send(:javascript_object_for, value)}")
        end

        def function_chain
          @function_chain ||= @generator.instance_variable_get(:@lines)
        end

        def append_to_function_chain!(call)
          function_chain[-1].chomp!(';')
          function_chain[-1] += ".#{call};"
        end
    end

    class JavaScriptElementProxy < JavaScriptProxy #:nodoc:
      def initialize(generator, id)
        @id = id
        super(generator, "$(#{::ActiveSupport::JSON.encode(id)})")
      end

      # Allows access of element attributes through +attribute+. Examples:
      #
      #   page['foo']['style']                  # => $('foo').style;
      #   page['foo']['style']['color']         # => $('blank_slate').style.color;
      #   page['foo']['style']['color'] = 'red' # => $('blank_slate').style.color = 'red';
      #   page['foo']['style'].color = 'red'    # => $('blank_slate').style.color = 'red';
      def [](attribute)
        append_to_function_chain!(attribute)
        self
      end

      def []=(variable, value)
        assign(variable, value)
      end

      def replace_html(*options_for_render)
        call 'update', @generator.send(:render, *options_for_render)
      end

      def replace(*options_for_render)
        call 'replace', @generator.send(:render, *options_for_render)
      end

      def reload(options_for_replace = {})
        replace(options_for_replace.merge({ :partial => @id.to_s }))
      end

    end

    class JavaScriptVariableProxy < JavaScriptProxy #:nodoc:
      def initialize(generator, variable)
        @variable = variable
        @empty    = true # only record lines if we have to.  gets rid of unnecessary linebreaks
        super(generator)
      end

      # The JSON Encoder calls this to check for the +to_json+ method
      # Since it's a blank slate object, I suppose it responds to anything.
      def respond_to?(method)
        true
      end

      def to_json(options = nil)
        @variable
      end

      private
        def append_to_function_chain!(call)
          @generator << @variable if @empty
          @empty = false
          super
        end
    end

    class JavaScriptCollectionProxy < JavaScriptProxy #:nodoc:
      ENUMERABLE_METHODS_WITH_RETURN = [:all, :any, :collect, :map, :detect, :find, :find_all, :select, :max, :min, :partition, :reject, :sort_by, :in_groups_of, :each_slice] unless defined? ENUMERABLE_METHODS_WITH_RETURN
      ENUMERABLE_METHODS = ENUMERABLE_METHODS_WITH_RETURN + [:each] unless defined? ENUMERABLE_METHODS
      attr_reader :generator
      delegate :arguments_for_call, :to => :generator

      def initialize(generator, pattern)
        super(generator, @pattern = pattern)
      end

      def each_slice(variable, number, &block)
        if block
          enumerate :eachSlice, :variable => variable, :method_args => [number], :yield_args => %w(value index), :return => true, &block
        else
          add_variable_assignment!(variable)
          append_enumerable_function!("eachSlice(#{::ActiveSupport::JSON.encode(number)});")
        end
      end

      def grep(variable, pattern, &block)
        enumerate :grep, :variable => variable, :return => true, :method_args => [pattern], :yield_args => %w(value index), &block
      end

      def in_groups_of(variable, number, fill_with = nil)
        arguments = [number]
        arguments << fill_with unless fill_with.nil?
        add_variable_assignment!(variable)
        append_enumerable_function!("inGroupsOf(#{arguments_for_call arguments});")
      end

      def inject(variable, memo, &block)
        enumerate :inject, :variable => variable, :method_args => [memo], :yield_args => %w(memo value index), :return => true, &block
      end

      def pluck(variable, property)
        add_variable_assignment!(variable)
        append_enumerable_function!("pluck(#{::ActiveSupport::JSON.encode(property)});")
      end

      def zip(variable, *arguments, &block)
        add_variable_assignment!(variable)
        append_enumerable_function!("zip(#{arguments_for_call arguments}")
        if block
          function_chain[-1] += ", function(array) {"
          yield ::ActiveSupport::JSON::Variable.new('array')
          add_return_statement!
          @generator << '});'
        else
          function_chain[-1] += ');'
        end
      end

      private
        def method_missing(method, *arguments, &block)
          if ENUMERABLE_METHODS.include?(method)
            returnable = ENUMERABLE_METHODS_WITH_RETURN.include?(method)
            variable   = arguments.first if returnable
            enumerate(method, {:variable => (arguments.first if returnable), :return => returnable, :yield_args => %w(value index)}, &block)
          else
            super
          end
        end

        # Options
        #   * variable - name of the variable to set the result of the enumeration to
        #   * method_args - array of the javascript enumeration method args that occur before the function
        #   * yield_args - array of the javascript yield args
        #   * return - true if the enumeration should return the last statement
        def enumerate(enumerable, options = {}, &block)
          options[:method_args] ||= []
          options[:yield_args]  ||= []
          yield_args  = options[:yield_args] * ', '
          method_args = arguments_for_call options[:method_args] # foo, bar, function
          method_args << ', ' unless method_args.blank?
          add_variable_assignment!(options[:variable]) if options[:variable]
          append_enumerable_function!("#{enumerable.to_s.camelize(:lower)}(#{method_args}function(#{yield_args}) {")
          # only yield as many params as were passed in the block
          yield(*options[:yield_args].collect { |p| JavaScriptVariableProxy.new(@generator, p) }[0..block.arity-1])
          add_return_statement! if options[:return]
          @generator << '});'
        end

        def add_variable_assignment!(variable)
          function_chain.push("var #{variable} = #{function_chain.pop}")
        end

        def add_return_statement!
          unless function_chain.last =~ /return/
            function_chain.push("return #{function_chain.pop.chomp(';')};")
          end
        end

        def append_enumerable_function!(call)
          function_chain[-1].chomp!(';')
          function_chain[-1] += ".#{call}"
        end
    end

    class JavaScriptElementCollectionProxy < JavaScriptCollectionProxy #:nodoc:\
      def initialize(generator, pattern)
        super(generator, "$$(#{::ActiveSupport::JSON.encode(pattern)})")
      end
    end
  end
end

require 'action_view/helpers/javascript_helper'