This file is indexed.

/usr/share/pyshared/MoinMoin/PageEditor.py is in python-moinmoin 1.9.3-1ubuntu2.3.

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
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
# -*- coding: iso-8859-1 -*-
"""
    MoinMoin - PageEditor class

    PageEditor is used for r/w access to a wiki page (edit, rename, delete operations).

    TODO:
    * See comments in Page.py, most apply here, too.
    * The editor code should be modularized so we will be able to use it for any
      text/* mimetype data with some special features enabled depending on the
      mimetype (e.g. enable wiki markup help when editing wiki mimetype).

    @copyright: 2000-2004 by Juergen Hermann <jh@web.de>,
                2005-2007 by MoinMoin:ThomasWaldmann,
                2007 by MoinMoin:ReimarBauer
    @license: GNU GPL, see COPYING for details.
"""

import os, time, codecs, errno


from MoinMoin import caching, config, wikiutil, error
from MoinMoin.Page import Page
from MoinMoin.widget import html
from MoinMoin.widget.dialog import Status
from MoinMoin.logfile import editlog, eventlog
from MoinMoin.mail.sendmail import encodeSpamSafeEmail
from MoinMoin.support.python_compatibility import set
from MoinMoin.util import filesys, timefuncs, web
from MoinMoin.events import PageDeletedEvent, PageRenamedEvent, PageCopiedEvent, PageRevertedEvent
from MoinMoin.events import PagePreSaveEvent, Abort, send_event
import MoinMoin.events.notification as notification

# used for merging
conflict_markers = ("\n---- /!\\ '''Edit conflict - other version:''' ----\n",
                    "\n---- /!\\ '''Edit conflict - your version:''' ----\n",
                    "\n---- /!\\ '''End of edit conflict''' ----\n")


#############################################################################
### Javascript code for editor page
#############################################################################

# we avoid the "--" operator to make this XHTML happy!
_countdown_js = """
%(countdown_script)s
<script type="text/javascript">
var countdown_timeout_min = %(lock_timeout)s
var countdown_lock_expire = "%(lock_expire)s"
var countdown_lock_mins = "%(lock_mins)s"
var countdown_lock_secs = "%(lock_secs)s"
addLoadEvent(countdown)
</script>
"""


#############################################################################
### PageEditor - Edit pages
#############################################################################
class PageEditor(Page):
    """ Editor for a wiki page. """

    # exceptions for .saveText()
    class SaveError(error.Error):
        pass
    class RevertError(SaveError):
        pass
    class AccessDenied(SaveError):
        pass
    class Immutable(AccessDenied):
        pass
    class NoAdmin(AccessDenied):
        pass
    class EmptyPage(SaveError):
        pass
    class Unchanged(SaveError):
        pass
    class EditConflict(SaveError):
        pass
    class CouldNotLock(SaveError):
        pass

    def __init__(self, request, page_name, **keywords):
        """ Create page editor object.

        @param page_name: name of the page
        @param request: the request object
        @keyword do_revision_backup: if 0, suppress making a page backup per revision
        @keyword do_editor_backup: if 0, suppress saving of draft copies
        @keyword uid_override: override user id and name (default None)
        """
        Page.__init__(self, request, page_name, **keywords)
        self._ = request.getText

        self.do_revision_backup = keywords.get('do_revision_backup', 1)
        self.do_editor_backup = keywords.get('do_editor_backup', 1)
        self.uid_override = keywords.get('uid_override', None)

        self.lock = PageLock(self)

    def mergeEditConflict(self, origrev):
        """ Try to merge current page version with new version the user tried to save

        @param origrev: the original revision the user was editing
        @rtype: bool
        @return: merge success status
        """
        from MoinMoin.util import diff3
        allow_conflicts = 1

        # Get current editor text
        savetext = self.get_raw_body()

        # The original text from the revision the user was editing
        original_text = Page(self.request, self.page_name, rev=origrev).get_raw_body()

        # The current revision someone else saved
        saved_text = Page(self.request, self.page_name).get_raw_body()

        # And try to merge all into one with edit conflict separators
        verynewtext = diff3.text_merge(original_text, saved_text, savetext,
                                       allow_conflicts, *conflict_markers)
        if verynewtext:
            self.set_raw_body(verynewtext)
            return True

        # this should never happen, except for empty pages
        return False

    def sendconfirmleaving(self):
        """ Prevents moving away from the page without saving it. """
        _ = self._
        self.request.write(u'''\
<script type="text/javascript">
    var flgChange = false;
    function confirmleaving() {
        if ( flgChange )
            return "%s";
    }
</script>
''' % _("Your changes are not saved!"))

    def sendEditor(self, **kw):
        """ Send the editor form page.

        @keyword preview: if given, show this text in preview mode
        @keyword staytop: don't go to #preview
        @keyword comment: comment field (when preview is true)
        """
        from MoinMoin import i18n
        from MoinMoin.action import SpellCheck
        request = self.request
        form = request.form
        _ = self._

        raw_body = ''
        msg = None
        conflict_msg = None
        edit_lock_message = None
        preview = kw.get('preview', None)
        staytop = kw.get('staytop', 0)

        from MoinMoin.formatter.text_html import Formatter
        request.formatter = Formatter(request, store_pagelinks=1)

        # check edit permissions
        if not request.user.may.write(self.page_name):
            msg = _('You are not allowed to edit this page.')
        elif not self.isWritable():
            msg = _('Page is immutable!')
        elif self.rev:
            # Trying to edit an old version, this is not possible via
            # the web interface, but catch it just in case...
            msg = _('Cannot edit old revisions!')
        else:
            try:
                # try to acquire edit lock
                ok, edit_lock_message = self.lock.acquire()
                if not ok:
                    # failed to get the lock
                    if preview is not None:
                        edit_lock_message = _('The lock you held timed out. Be prepared for editing conflicts!'
                            ) + "<br>" + edit_lock_message
                    else:
                        msg = edit_lock_message
            except OSError, err:
                if err.errno == errno.ENAMETOOLONG:
                    msg = _("Page name is too long, try shorter name.")
                else:
                    raise

        # Did one of the prechecks fail?
        if msg:
            request.theme.add_msg(msg, "error")
            self.send_page()
            return

        # Emit http_headers after checks (send_page)
        request.disableHttpCaching(level=2)

        # check if we want to load a draft
        use_draft = None
        if 'button_load_draft' in form:
            wanted_draft_timestamp = int(form.get('draft_ts', '0'))
            if wanted_draft_timestamp:
                draft = self._load_draft()
                if draft is not None:
                    draft_timestamp, draft_rev, draft_text = draft
                    if draft_timestamp == wanted_draft_timestamp:
                        use_draft = draft_text

        # Check for draft / normal / preview submit
        if use_draft is not None:
            title = _('Draft of "%(pagename)s"')
            # Propagate original revision
            rev = int(form['draft_rev'])
            self.set_raw_body(use_draft, modified=1)
            preview = use_draft
        elif preview is None:
            title = _('Edit "%(pagename)s"')
        else:
            title = _('Preview of "%(pagename)s"')
            # Propagate original revision
            rev = request.rev
            self.set_raw_body(preview, modified=1)

        # send header stuff
        lock_timeout = self.lock.timeout / 60
        lock_page = wikiutil.escape(self.page_name, quote=1)
        lock_expire = _("Your edit lock on %(lock_page)s has expired!") % {'lock_page': lock_page}
        lock_mins = _("Your edit lock on %(lock_page)s will expire in # minutes.") % {'lock_page': lock_page}
        lock_secs = _("Your edit lock on %(lock_page)s will expire in # seconds.") % {'lock_page': lock_page}

        # get request parameters
        try:
            text_rows = int(form['rows'])
        except StandardError:
            text_rows = self.cfg.edit_rows
            if request.user.valid:
                text_rows = int(request.user.edit_rows)

        if preview is not None:
            # Check for editing conflicts
            if not self.exists():
                # page does not exist, are we creating it?
                if rev:
                    conflict_msg = _('Someone else deleted this page while you were editing!')
            elif rev != self.current_rev():
                conflict_msg = _('Someone else changed this page while you were editing!')
                if self.mergeEditConflict(rev):
                    conflict_msg = _("""Someone else saved this page while you were editing!
Please review the page and save then. Do not save this page as it is!""")
                    rev = self.current_rev()
            if conflict_msg:
                # We don't show preview when in conflict
                preview = None

        elif self.exists():
            # revision of existing page
            rev = self.current_rev()
        else:
            # page creation
            rev = 0

        # Page editing is done using user language
        request.setContentLanguage(request.lang)

        # Get the text body for the editor field.
        # TODO: what about deleted pages? show the text of the last revision or use the template?
        if preview is not None:
            raw_body = self.get_raw_body()
            if use_draft:
                request.theme.add_msg(_("[Content loaded from draft]"), 'info')
        elif self.exists():
            # If the page exists, we get the text from the page.
            # TODO: maybe warn if template argument was ignored because the page exists?
            raw_body = self.get_raw_body()
        elif 'template' in request.values:
            # If the page does not exist, we try to get the content from the template parameter.
            template_page = wikiutil.unquoteWikiname(request.values['template'])
            template_page_escaped = wikiutil.escape(template_page)
            if request.user.may.read(template_page):
                raw_body = Page(request, template_page).get_raw_body()
                if raw_body:
                    request.theme.add_msg(_("[Content of new page loaded from %s]") % (template_page_escaped, ), 'info')
                else:
                    request.theme.add_msg(_("[Template %s not found]") % (template_page_escaped, ), 'warning')
            else:
                request.theme.add_msg(_("[You may not read %s]") % (template_page_escaped, ), 'error')

        # Make backup on previews - but not for new empty pages
        if not use_draft and preview and raw_body:
            self._save_draft(raw_body, rev)

        draft_message = None
        loadable_draft = False
        if preview is None:
            draft = self._load_draft()
            if draft is not None:
                draft_timestamp, draft_rev, draft_text = draft
                if draft_text != raw_body:
                    loadable_draft = True
                    page_rev = rev
                    draft_timestamp_str = request.user.getFormattedDateTime(draft_timestamp)
                    draft_message = _(u"'''<<BR>>Your draft based on revision %(draft_rev)d (saved %(draft_timestamp_str)s) can be loaded instead of the current revision %(page_rev)d by using the load draft button - in case you lost your last edit somehow without saving it.''' A draft gets saved for you when you do a preview, cancel an edit or unsuccessfully save.", wiki=True) % locals()

        # Setup status message
        status = [kw.get('msg', ''), conflict_msg, edit_lock_message, draft_message]
        status = [msg for msg in status if msg]
        status = ' '.join(status)
        status = Status(request, content=status)
        request.theme.add_msg(status, "dialog")

        request.theme.send_title(
            title % {'pagename': self.split_title(), },
            page=self,
            html_head=self.lock.locktype and (
                _countdown_js % {
                     'countdown_script': request.theme.externalScript('countdown'),
                     'lock_timeout': lock_timeout,
                     'lock_expire': lock_expire,
                     'lock_mins': lock_mins,
                     'lock_secs': lock_secs,
                    }) or '',
            editor_mode=1,
            allow_doubleclick=1,
        )

        request.write(request.formatter.startContent("content"))

        # Generate default content for new pages
        if not raw_body:
            raw_body = _('Describe %s here.') % (self.page_name, )

        # send form
        request.write('<form id="editor" method="post" action="%s#preview" onSubmit="flgChange = false;">' % (
                request.href(self.page_name)
        ))

        # yet another weird workaround for broken IE6 (it expands the text
        # editor area to the right after you begin to type...). IE sucks...
        # http://fplanque.net/2003/Articles/iecsstextarea/
        request.write('<fieldset style="border:none;padding:0;">')

        request.write(unicode(html.INPUT(type="hidden", name="action", value="edit")))

        # Send revision of the page our edit is based on
        request.write('<input type="hidden" name="rev" value="%d">' % (rev, ))

        # Create and send a ticket, so we can check the POST
        request.write('<input type="hidden" name="ticket" value="%s">' % wikiutil.createTicket(request))

        # Save backto in a hidden input
        backto = request.values.get('backto')
        if backto:
            request.write(unicode(html.INPUT(type="hidden", name="backto", value=backto)))

        # button bar
        button_spellcheck = '<input class="button" type="submit" name="button_spellcheck" value="%s" onClick="flgChange = false;">' % _('Check Spelling')

        save_button_text = _('Save Changes')
        cancel_button_text = _('Cancel')

        if self.cfg.page_license_enabled:
            request.write('<p><em>', _(
"""By hitting '''%(save_button_text)s''' you put your changes under the %(license_link)s.
If you don't want that, hit '''%(cancel_button_text)s''' to cancel your changes.""", wiki=True) % {
                'save_button_text': save_button_text,
                'cancel_button_text': cancel_button_text,
                'license_link': wikiutil.getLocalizedPage(request, self.cfg.page_license_page).link_to(request),
            }, '</em></p>')


        request.write('''
<input class="button" type="submit" name="button_save" value="%s" onClick="flgChange = false;">
<input class="button" type="submit" name="button_preview" value="%s" onClick="flgChange = false;">
''' % (save_button_text, _('Preview'), ))

        if not (request.cfg.editor_force and request.cfg.editor_default == 'text'):
            request.write('''
<input id="switch2gui" style="display: none;" class="button" type="submit" name="button_switch" value="%s">
''' % (_('GUI Mode'), ))

        if loadable_draft:
            request.write('''
<input class="button" type="submit" name="button_load_draft" value="%s" onClick="flgChange = false;">
<input type="hidden" name="draft_ts" value="%d">
<input type="hidden" name="draft_rev" value="%d">
''' % (_('Load Draft'), draft_timestamp, draft_rev))

        request.write('''
%s
<input class="button" type="submit" name="button_cancel" value="%s">
<input type="hidden" name="editor" value="text">
''' % (button_spellcheck, cancel_button_text, ))

        # Trivial Change-checkbox to the top of the page, shows up only if user has JavaScript enabled. It's "linked" with the bottom's box (checking one checks both)
        if self.cfg.mail_enabled:
            request.write('''
<script type="text/javascript">
    <!--
    function toggle_trivial(CheckedBox)
    {
        TrivialBoxes = document.getElementsByName("trivial");
        for (var i = 0; i < TrivialBoxes.length; i++)
            TrivialBoxes[i].checked = CheckedBox.checked;
    }

    document.write('<input type="checkbox" name="trivial" id="chktrivialtop" value="1" %(checked)s onclick="toggle_trivial(this)">');
    document.write('<label for="chktrivialtop">%(label)s</label>');
    //-->
</script> ''' % {
                'checked': ('', 'checked')[form.get('trivial', '0') == '1'],
                'label': _("Trivial change"),
            })

        from MoinMoin.security.textcha import TextCha
        request.write(TextCha(request).render())

        # Add textarea with page text
        self.sendconfirmleaving()

        lang = self.pi.get('language', request.cfg.language_default)

        if not text_rows:
            # if no specific value is given for editor height, but 0, we
            # compute the rows from the raw_body line count plus some
            # extra rows for adding new text in the editor. Maybe this helps
            # with the "double slider" usability issue, esp. for devices like
            # the iphone where you can't operate both sliders.
            current_rows = len(raw_body.split('\n'))
            text_rows = max(10, int(current_rows * 1.5))

        request.write(
            u'''\
<textarea id="editor-textarea" name="savetext" lang="%(lang)s" dir="%(dir)s" rows="%(rows)d" cols="80"
          onChange="flgChange = true;" onKeyPress="flgChange = true;">\
%(text)s\
</textarea>''' % {
            'lang': lang,
            'dir': i18n.getDirection(lang),
            'rows': text_rows,
            'text': wikiutil.escape(raw_body)
        })

        request.write("<p>")
        request.write(_("Comment:"),
            ' <input id="editor-comment" type="text" name="comment" value="%s" size="80" maxlength="200"'
            ' onChange="flgChange = true;" onKeyPress="flgChange = true;">' % (
                wikiutil.escape(kw.get('comment', ''), 1), ))
        request.write("</p>")

        # Category selection
        filterfn = self.cfg.cache.page_category_regexact.search
        cat_pages = request.rootpage.getPageList(filter=filterfn)
        cat_pages.sort()
        cat_pages = [wikiutil.pagelinkmarkup(p) for p in cat_pages]
        cat_pages.insert(0, ('', _('<No addition>')))
        request.write("<p>")
        request.write(_('Add to: %(category)s') % {
            'category': unicode(web.makeSelection('category', cat_pages)),
        })

        if self.cfg.mail_enabled:
            request.write('''
&nbsp;

<input type="checkbox" name="trivial" id="chktrivial" value="1" %(checked)s onclick="toggle_trivial(this)">
<label for="chktrivial">%(label)s</label>

''' % {
                'checked': ('', 'checked')[form.get('trivial', '0') == '1'],
                'label': _("Trivial change"),
                })

        request.write('''
&nbsp;
<input type="checkbox" name="rstrip" id="chkrstrip" value="1" %(checked)s>
<label for="chkrstrip">%(label)s</label>
''' % {
            'checked': ('', 'checked')[form.get('rstrip', '0') == '1'],
            'label': _('Remove trailing whitespace from each line')
            })
        request.write("</p>")

        badwords_re = None
        if preview is not None:
            if 'button_spellcheck' in form or 'button_newwords' in form:
                badwords, badwords_re, msg = SpellCheck.checkSpelling(self, request, own_form=0)
                request.write("<p>%s</p>" % msg)
        request.write('</fieldset>')
        request.write("</form>")

        # QuickHelp originally by Georg Mischler <schorsch@lightingwiki.com>
        markup = self.pi['format'] or request.cfg.default_markup
        try:
            parser = wikiutil.searchAndImportPlugin(self.request.cfg, "parser", markup)
        except wikiutil.PluginMissingError:
            parser = wikiutil.searchAndImportPlugin(self.request.cfg, "parser", "plain")
        quickhelp = getattr(parser, 'quickhelp', None)
        if quickhelp:
            request.write(request.formatter.div(1, id="editor-help"))
            request.write(_(quickhelp, wiki=True))
            request.write(request.formatter.div(0))

        if preview is not None:
            if staytop:
                content_id = 'previewbelow'
            else:
                content_id = 'preview'
            self.send_page(content_id=content_id, content_only=1, hilite_re=badwords_re)

        request.write(request.formatter.endContent())
        request.theme.send_footer(self.page_name)
        request.theme.send_closing_html()

    def sendCancel(self, newtext, rev):
        """ User clicked on Cancel button.
            If edit locking is active, delete the current lock file.

        @param newtext: the edited text (which has been cancelled)
        @param rev: not used!?
        """
        request = self.request
        _ = self._
        self._save_draft(newtext, rev) # shall we really save a draft on CANCEL?
        self.lock.release()

        backto = request.values.get('backto')
        if backto:
            pg = Page(request, backto)
            request.http_redirect(pg.url(request))
        else:
            request.theme.add_msg(_('Edit was cancelled.'), "error")
            self.send_page()

    def copyPage(self, newpagename, comment=u''):
        """ Copy the current version of the page (keeping the backups, logs and attachments).

        @param comment: Comment given by user
        @rtype: unicode
        @return: success flag, error message
        """
        request = self.request
        _ = self._

        if not newpagename:
            return False, _("You can't copy to an empty pagename.")

        if not self.request.user.may.write(newpagename):
            return False, _('You are not allowed to copy this page!')

        newpage = PageEditor(request, newpagename)

        pageexists_error = _("""'''A page with the name {{{'%s'}}} already exists.'''

Try a different name.""", wiki=True) % (wikiutil.escape(newpagename), )

        # Check whether a page with the new name already exists
        if newpage.exists(includeDeleted=1):
            return False, pageexists_error

        # Get old page text
        savetext = self.get_raw_body()

        oldpath = self.getPagePath(check_create=0)
        newpath = newpage.getPagePath(check_create=0)

        # Copy page
        # NOTE: might fail if another process created newpagename just
        try:
            filesys.copytree(oldpath, newpath)
            self.error = None
            savetext = u"## page was copied from %s\n%s" % (self.page_name, savetext)
            Page.__init__(self, request, newpagename)
            self._write_file(savetext, "SAVENEW", comment)

            event = PageCopiedEvent(request, newpage, self, comment)
            send_event(event)

            return True, None
        except OSError, err:
            # Try to understand what happened. Maybe its better to check
            # the error code, but I just reused the available code above...
            if newpage.exists(includeDeleted=1):
                return False, pageexists_error
            else:
                return False, _('Could not copy page because of file system error: %s.') % unicode(err)

    def renamePage(self, newpagename, comment=u''):
        """ Rename the current version of the page (making a backup before deletion
            and keeping the backups, logs and attachments).

        @param comment: Comment given by user
        @rtype: unicode
        @return: success flag, error message
        """
        request = self.request
        _ = self._

        if not (request.user.may.delete(self.page_name)
                and request.user.may.write(newpagename)):
            msg = _('You are not allowed to rename this page!')
            raise self.AccessDenied, msg

        if not newpagename:
            return False, _("You can't rename to an empty pagename.")

        newpage = PageEditor(request, newpagename)

        pageexists_error = _("""'''A page with the name {{{'%s'}}} already exists.'''

Try a different name.""", wiki=True) % (wikiutil.escape(newpagename), )

        # Check whether a page with the new name already exists
        if newpage.exists(includeDeleted=1):
            return False, pageexists_error

        # Get old page text
        savetext = self.get_raw_body()

        oldpath = self.getPagePath(check_create=0)
        newpath = newpage.getPagePath(check_create=0)

        # Rename page

        # NOTE: might fail if another process created newpagename just
        # NOW, while you read this comment. Rename is atomic for files -
        # but for directories, rename will fail if the directory
        # exists. We should have global edit-lock to avoid this.
        # See http://docs.python.org/lib/os-file-dir.html
        try:
            os.rename(oldpath, newpath)
            self.error = None
            # Save page text with a comment about the old name
            savetext = u"## page was renamed from %s\n%s" % (self.page_name, savetext)
            newpage.saveText(savetext, 0, comment=comment, extra=self.page_name, action='SAVE/RENAME', notify=False)
            # delete pagelinks
            arena = newpage
            key = 'pagelinks'
            cache = caching.CacheEntry(request, arena, key, scope='item')
            cache.remove()

            # clean the cache
            for formatter_name in self.cfg.caching_formats:
                arena = newpage
                key = formatter_name
                cache = caching.CacheEntry(request, arena, key, scope='item')
                cache.remove()

            event = PageRenamedEvent(request, newpage, self, comment)
            send_event(event)

            return True, None
        except OSError, err:
            # Try to understand what happened. Maybe its better to check
            # the error code, but I just reused the available code above...
            if newpage.exists(includeDeleted=1):
                return False, pageexists_error
            else:
                return False, _('Could not rename page because of file system error: %s.') % unicode(err)


    def revertPage(self, revision, comment=u''):
        """ Reverts page to the given revision

        @param revision: revision to revert to
        @type revision: int

        """
        _ = self.request.getText

        if not self.request.user.may.revert(self.page_name):
            # no real message necessary, cannot happen if
            # user doesn't try to exploit us
            raise self.RevertError('not allowed')
        elif revision is None:
            # see above
            raise self.RevertError('cannot revert to current rev')
        else:
            revstr = '%08d' % revision
            pg = Page(self.request, self.page_name, rev=revision)
            msg = self.saveText(pg.get_raw_body(), 0, extra=revstr, action="SAVE/REVERT", notify=False, comment=comment)

            # Remove cache entry (if exists)
            pg = Page(self.request, self.page_name)
            key = self.request.form.get('key', 'text_html') # XXX see cleanup code in deletePage
            caching.CacheEntry(self.request, pg, key, scope='item').remove()
            caching.CacheEntry(self.request, pg, "pagelinks", scope='item').remove()

            # Notify observers
            e = PageRevertedEvent(self.request, self.page_name, revision, revstr)
            send_event(e)

            return msg

    def deletePage(self, comment=None):
        """ Delete the current version of the page (making a backup before deletion
            and keeping the backups, logs and attachments).

        @param comment: Comment given by user
        @rtype: unicode
        @return: success flag, error message
        """
        request = self.request
        _ = self._
        success = True
        if not (request.user.may.write(self.page_name)
                and request.user.may.delete(self.page_name)):
            msg = _('You are not allowed to delete this page!')
            raise self.AccessDenied, msg

        try:
            msg = self.saveText(u"deleted\n", 0, comment=comment or u'', deleted=True, notify=False)
            msg = msg.replace(
                _("Thank you for your changes. Your attention to detail is appreciated."),
                _('Page "%s" was successfully deleted!') % (wikiutil.escape(self.page_name), ))

            event = PageDeletedEvent(request, self, comment)
            send_event(event)

        except self.SaveError, message:
            # XXX do not only catch base class SaveError here, but
            # also the derived classes, so we can give better err msgs
            success = False
            msg = "SaveError has occured in PageEditor.deletePage. We need locking there."

        # delete pagelinks
        arena = self
        key = 'pagelinks'
        cache = caching.CacheEntry(request, arena, key, scope='item')
        cache.remove()

        # clean the cache
        for formatter_name in self.cfg.caching_formats:
            arena = self
            key = formatter_name
            cache = caching.CacheEntry(request, arena, key, scope='item')
            cache.remove()
        return success, msg

    def _get_local_timestamp(self):
        """ Returns the string that can be used by the TIME substitution.

        @return: str with a timestamp in it
        """

        now = time.time()
        # default: UTC
        zone = "Z"
        u = self.request.user

        # setup the timezone
        if u.valid and u.tz_offset:
            tz = u.tz_offset
            # round to minutes
            tz -= tz % 60
            minutes = tz / 60
            hours = minutes / 60
            minutes -= hours * 60

            # construct the offset
            zone = "%+0.2d%02d" % (hours, minutes)
            # correct the time by the offset we've found
            now += tz

        return time.strftime("%Y-%m-%dT%H:%M:%S", timefuncs.tmtuple(now)) + zone

    def _expand_variables(self, text):
        """ Expand @VARIABLE@ in `text`and return the expanded text.

        @param text: current text of wikipage
        @rtype: string
        @return: new text of wikipage, variables replaced
        """
        # TODO: Allow addition of variables via wikiconfig or a global wiki dict.
        request = self.request
        now = self._get_local_timestamp()
        u = request.user
        obfuscated_email_address = encodeSpamSafeEmail(u.email)
        signature = u.signature()
        variables = {
            'PAGE': self.page_name,
            'TIMESTAMP': now,
            'TIME': "<<DateTime(%s)>>" % now,
            'DATE': "<<Date(%s)>>" % now,
            'ME': u.name,
            'USERNAME': signature,
            'USER': "-- %s" % signature,
            'SIG': "-- %s <<DateTime(%s)>>" % (signature, now),
            'EMAIL': "<<MailTo(%s)>>" % (obfuscated_email_address)
        }

        if u.valid and u.name:
            if u.email:
                variables['MAILTO'] = "<<MailTo(%s)>>" % u.email
            # Users can define their own variables via
            # UserHomepage/MyDict, which override the default variables.
            userDictPage = u.name + "/MyDict"
            if userDictPage in request.dicts:
                variables.update(request.dicts[userDictPage])

        for name in variables:
            text = text.replace('@%s@' % name, variables[name])
        return text

    def normalizeText(self, text, **kw):
        """ Normalize text

        Make sure text uses '\n' line endings, and has a trailing
        newline. Strip whitespace on end of lines if needed.

        You should normalize any text you enter into a page, for
        example, when getting new text from the editor, or when setting
        new text manually.

        @param text: text to normalize (unicode)
        @keyword stripspaces: if 1, strip spaces from text
        @rtype: unicode
        @return: normalized text
        """
        if text:
            lines = text.splitlines()
            # Strip trailing spaces if needed
            if kw.get('stripspaces', 0):
                lines = [line.rstrip() for line in lines]
            # Add final newline if not present, better for diffs (does
            # not include former last line when just adding text to
            # bottom; idea by CliffordAdams)
            if not lines[-1] == u'':
                # '' will make newline after join
                lines.append(u'')

            text = u'\n'.join(lines)
        return text

    def _save_draft(self, text, rev, **kw):
        """ Save an editor backup to the drafts cache arena.

        @param text: draft text of the page
                     (if None, the draft gets removed from the cache)
        @param rev: the revision of the page this draft is based on
        @param kw: no keyword args used currently
        """
        request = self.request
        if not request.user.valid or not self.do_editor_backup:
            return None

        arena = 'drafts'
        key = request.user.id
        cache = caching.CacheEntry(request, arena, key, scope='wiki', use_pickle=True)
        if cache.exists():
            cache_data = cache.content()
        else:
            cache_data = {}
        pagename = self.page_name
        if text is None:
            try:
                del cache_data[pagename]
            except:
                pass
        else:
            timestamp = int(time.time())
            cache_data[pagename] = (timestamp, rev, text)
        cache.update(cache_data)

    def _load_draft(self):
        """ Get a draft from the drafts cache arena.

        @rtype: unicode
        @return: draft text or None
        """
        request = self.request
        if not request.user.valid:
            return None

        arena = 'drafts'
        key = request.user.id
        cache = caching.CacheEntry(request, arena, key, scope='wiki', use_pickle=True)
        pagename = self.page_name
        try:
            cache_data = cache.content()
            return cache_data.get(pagename)
        except caching.CacheError:
            return None

    def copy_underlay_page(self):
        # renamed from copypage to avoid conflicts with copyPage
        """ Copy a page from underlay directory to page directory """
        src = self.getPagePath(use_underlay=1, check_create=0)
        dst = self.getPagePath(use_underlay=0, check_create=0)
        if src and dst and src != dst and os.path.exists(src):
            try:
                os.rmdir(dst) # simply remove empty dst dirs
                # XXX in fact, we should better remove anything we regard as an
                # empty page, maybe also if there is also an edit-lock or
                # empty cache. revisions subdir...
            except:
                pass
            if not os.path.exists(dst):
                filesys.copytree(src, dst)
                self.reset() # reinit stuff

    def _write_file(self, text, action='SAVE', comment=u'', extra=u'', deleted=False):
        """ Write the text to the page file (and make a backup of old page).

        @param text: text to save for this page
        @param deleted: if True, then don't write page content (used by deletePage)
        @rtype: int
        @return: mtime_usec of new page
        """
        request = self.request
        _ = self._
        was_deprecated = self.pi.get('deprecated', False)

        self.copy_underlay_page()

        # remember conflict state
        self.setConflict(wikiutil.containsConflictMarker(text))

        # Write always on the standard directory, never change the
        # underlay directory copy!
        pagedir = self.getPagePath(use_underlay=0, check_create=0)

        revdir = os.path.join(pagedir, 'revisions')
        cfn = os.path.join(pagedir, 'current')
        clfn = os.path.join(pagedir, 'current-locked')
        cltfn = os.path.join(pagedir, 'current-locked.tmp')

        # !!! these log objects MUST be created outside the locked area !!!

        # The local log should be the standard edit log, not the
        # underlay copy log!
        pagelog = self.getPagePath('edit-log', use_underlay=0, isfile=1)
        llog = editlog.EditLog(request, filename=pagelog,
                               uid_override=self.uid_override)
        # Open the global log
        glog = editlog.EditLog(request, uid_override=self.uid_override)

        if not os.path.exists(pagedir): # new page, create and init pagedir
            os.mkdir(pagedir)
        if not os.path.exists(revdir):
            os.mkdir(revdir)
            f = file(cfn, 'w')
            f.write('%08d\n' % 0)
            f.close()

        got_lock = False
        retry = 0

        try:
            while not got_lock and retry < 100:
                retry += 1
                try:
                    filesys.rename(cfn, clfn)
                    got_lock = True
                except OSError, err:
                    got_lock = False
                    if err.errno == 2: # there was no 'current' file
                        time.sleep(0.1)
                    else:
                        raise self.CouldNotLock, _("Page could not get locked. Unexpected error (errno=%d).") % err.errno

            if not got_lock:
                raise self.CouldNotLock, _("Page could not get locked. Missing 'current' file?")

            # increment rev number of current(-locked) page
            f = file(clfn)
            revstr = f.read()
            f.close()
            try:
                rev = int(revstr)
            except ValueError, err:
                raise self.SaveError, _("Unable to determine current page revision from the 'current' file. The page %s is damaged and cannot be edited right now.") % self.page_name

            if not was_deprecated:
                if self.do_revision_backup or rev == 0:
                    rev += 1
            revstr = '%08d' % rev
            # write the current page rev to a temporary file
            try:
                f = file(cltfn, 'w')
                f.write(revstr+'\n')
                f.close()
            except IOError, err:
                try:
                    os.remove(cltfn)
                except:
                    pass # we don't care for errors in the os.remove
                # throw a nicer exception
                if err.errno == errno.ENOSPC:
                    raise self.SaveError, _("Cannot save page %s, no storage space left.") % self.page_name
                else:
                    raise self.SaveError, _("An I/O error occurred while saving page %s (errno=%d)") % (self.page_name, err.errno)
            # atomically put it in place (except on windows)
            else:
                filesys.rename(cltfn, clfn)

            if not deleted:
                # save to page file
                pagefile = os.path.join(revdir, revstr)
                f = codecs.open(pagefile, 'wb', config.charset)
                # Write the file using text/* mime type
                f.write(self.encodeTextMimeType(text))
                f.close()
                mtime_usecs = wikiutil.timestamp2version(os.path.getmtime(pagefile))
                # set in-memory content
                self.set_raw_body(text)
            else:
                mtime_usecs = wikiutil.timestamp2version(time.time())
                # set in-memory content
                self.set_raw_body(None)

            # reset page object
            self.reset()

            # write the editlog entry
            # for now simply make 2 logs, better would be some multilog stuff maybe
            if self.do_revision_backup:
                # do not globally log edits with no revision backup
                # if somebody edits a deprecated page, log it in global log, but not local log
                glog.add(request, mtime_usecs, rev, action, self.page_name, None, extra, comment)
            if not was_deprecated and self.do_revision_backup:
                # if we did not create a new revision number, do not locally log it
                llog.add(request, mtime_usecs, rev, action, self.page_name, None, extra, comment)
        finally:
            if got_lock:
                filesys.rename(clfn, cfn)

        # add event log entry
        elog = eventlog.EventLog(request)
        elog.add(request, 'SAVEPAGE', {'pagename': self.page_name}, 1, mtime_usecs)

        return mtime_usecs, rev

    def saveText(self, newtext, rev, **kw):
        """ Save new text for a page.

        @param newtext: text to save for this page
        @param rev: revision of the page
        @keyword trivial: trivial edit (default: 0)
        @keyword extra: extra info field (e.g. for SAVE/REVERT with revno)
        @keyword comment: comment field (when preview is true)
        @keyword action: action for editlog (default: SAVE)
        @keyword index: needs indexing, not already handled (default: 1)
        @keyword deleted: if True, then don't save page content (used by DeletePage, default: False)
        @keyword notify: if False (default: True), don't send a PageChangedEvent
        @rtype: unicode
        @return: error msg
        """
        request = self.request
        _ = self._
        self._save_draft(newtext, rev, **kw)
        action = kw.get('action', 'SAVE')
        deleted = kw.get('deleted', False)
        notify = kw.get('notify', True)

        #!!! need to check if we still retain the lock here
        #!!! rev check is not enough since internal operations use "0"

        # expand variables, unless it's a template or form page
        if not wikiutil.isTemplatePage(request, self.page_name):
            newtext = self._expand_variables(newtext)

        msg = ""
        if not request.user.may.save(self, newtext, rev, **kw):
            msg = _('You are not allowed to edit this page!')
            raise self.AccessDenied, msg
        elif not self.isWritable():
            msg = _('Page is immutable!')
            raise self.Immutable, msg
        elif not newtext:
            msg = _('You cannot save empty pages.')
            raise self.EmptyPage, msg
        elif rev != 0 and rev != self.current_rev():
            # check if we already saved that page
            other = False
            pagelog = self.getPagePath('edit-log', use_underlay=0, isfile=1)
            next_line = None
            for line in editlog.EditLog(request, pagelog).reverse():
                if int(line.rev) == int(rev):
                    break
                if not line.is_from_current_user(request):
                    other = True
                next_line = line
            if next_line and next_line.is_from_current_user(request):
                saved_page = Page(request, self.page_name, rev=int(next_line.rev))
                if newtext == saved_page.get_raw_body():
                    msg = _("You already saved this page!")
                    return msg
                else:
                    msg = _("You already edited this page! Please do not use the back button.")
                    raise self.EditConflict, msg

                msg = _("""Someone else saved this page while you were editing!
Please review the page and save then. Do not save this page as it is!""")

            raise self.EditConflict, msg
        elif newtext == self.get_raw_body():
            msg = _('You did not change the page content, not saved!')
            self.lock.release()
            raise self.Unchanged, msg
        else:
            from MoinMoin.security import parseACL
            # Get current ACL and compare to new ACL from newtext. If
            # they are not the sames, the user must have admin
            # rights. This is a good place to update acl cache - instead
            # of wating for next request.
            acl = self.getACL(request)
            if (not request.user.may.admin(self.page_name) and
                parseACL(request, newtext).acl != acl.acl and
                action != "SAVE/REVERT"):
                msg = _("You can't change ACLs on this page since you have no admin rights on it!")
                raise self.NoAdmin, msg

        presave = PagePreSaveEvent(request, self, newtext)
        results = send_event(presave)

        for result in results:
            if isinstance(result, Abort):
                # XXX: this should return a list of messages to the sorrounding context
                # XXX: rather than dumbly concatenate them. Fix in the future.
                msg = msg + result.reason

        # save only if no error occurred (msg is empty) and no abort has been requested
        if not msg:
            # set success msg
            msg = _("Thank you for your changes. Your attention to detail is appreciated.")

            # determine action for edit log
            if action == 'SAVE' and not self.exists():
                action = 'SAVENEW'
            comment = kw.get('comment', u'')
            extra = kw.get('extra', u'')
            trivial = kw.get('trivial', 0)
            # write the page file
            mtime_usecs, rev = self._write_file(newtext, action, comment, extra, deleted=deleted)
            self._save_draft(None, None) # everything fine, kill the draft for this page

            if notify:
                # send notifications
                from MoinMoin import events

                if trivial:
                    e = events.TrivialPageChangedEvent(self.request, self, comment)
                else:
                    e = events.PageChangedEvent(self.request, self, comment)
                results = events.send_event(e)

                recipients = set()
                for result in results:
                    if isinstance(result, notification.Success):
                        recipients.update(result.recipients)

                        if recipients:
                            info = _("Notifications sent to:")
                            msg = msg + "<p>%s %s</p>" % (info, ", ".join(recipients))

            # Update page trail with the page we just saved.
            # This is needed for NewPage macro with backto because it does not
            # send the page we just saved.
            request.user.addTrail(self)

        # remove lock (forcibly if we were allowed to break it by the UI)
        # !!! this is a little fishy, since the lock owner might not notice
        # we broke his lock ==> but revision checking during preview will
        self.lock.release(force=not msg) # XXX does "not msg" make any sense?

        return msg


class PageLock:
    """ PageLock - Lock pages """
    # TODO: race conditions throughout, need to lock file during queries & update
    def __init__(self, pageobj):
        """
        """
        self.pageobj = pageobj
        self.page_name = pageobj.page_name
        request = pageobj.request
        self.request = request
        self._ = self.request.getText
        self.cfg = self.request.cfg

        # current time and user for later checks
        self.now = int(time.time())
        self.uid = request.user.valid and request.user.id or request.remote_addr

        # get details of the locking preference, i.e. warning or lock, and timeout
        self.locktype = None
        self.timeout = 10 * 60 # default timeout in minutes

        if self.cfg.edit_locking:
            lockinfo = self.cfg.edit_locking.split()
            if 1 <= len(lockinfo) <= 2:
                self.locktype = lockinfo[0].lower()
                if len(lockinfo) > 1:
                    try:
                        self.timeout = int(lockinfo[1]) * 60
                    except ValueError:
                        pass


    def acquire(self):
        """ Begin an edit lock depending on the mode chosen in the config.

        @rtype: tuple
        @return: tuple is returned containing 2 values:
              * a bool indicating successful acquiry
              * a string giving a reason for failure or an informational msg
        """
        if not self.locktype:
            # we are not using edit locking, so always succeed
            return 1, ''

        _ = self._
        #!!! race conditions, need to lock file during queries & update
        self._readLockFile()
        bumptime = self.request.user.getFormattedDateTime(self.now + self.timeout)
        timestamp = self.request.user.getFormattedDateTime(self.timestamp)
        owner = self.owner_html
        secs_valid = self.timestamp + self.timeout - self.now

        # do we own the lock, or is it stale?
        if self.owner is None or self.uid == self.owner or secs_valid < 0:
            # create or bump the lock
            self._writeLockFile()

            msg = []
            if self.owner is not None and -10800 < secs_valid < 0:
                mins_ago = secs_valid / -60
                msg.append(_(
                    "The lock of %(owner)s timed out %(mins_ago)d minute(s) ago,"
                    " and you were granted the lock for this page."
                    ) % {'owner': owner, 'mins_ago': mins_ago})

            if self.locktype == 'lock':
                msg.append(_(
                    "Other users will be ''blocked'' from editing this page until %(bumptime)s.",
                    wiki=True) % {'bumptime': bumptime})
            else:
                msg.append(_(
                    "Other users will be ''warned'' until %(bumptime)s that you are editing this page.",
                    wiki=True) % {'bumptime': bumptime})
            msg.append(_(
                "Use the Preview button to extend the locking period."
                ))
            result = 1, '\n'.join(msg)
        else:
            mins_valid = (secs_valid+59) / 60
            if self.locktype == 'lock':
                # lout out user
                result = 0, _(
                    "This page is currently ''locked'' for editing by %(owner)s until %(timestamp)s,"
                    " i.e. for %(mins_valid)d minute(s).",
                    wiki=True) % {'owner': owner, 'timestamp': timestamp, 'mins_valid': mins_valid}
            else:
                # warn user about existing lock

                result = 1, _(
"""This page was opened for editing or last previewed at %(timestamp)s by %(owner)s.<<BR>>
'''You should ''refrain from editing'' this page for at least another %(mins_valid)d minute(s),
to avoid editing conflicts.'''<<BR>>
To leave the editor, press the Cancel button.""", wiki=True) % {
                    'timestamp': timestamp, 'owner': owner, 'mins_valid': mins_valid}

        return result


    def release(self, force=0):
        """ Release lock, if we own it.

        @param force: if 1, unconditionally release the lock.
        """
        if self.locktype:
            # check that we own the lock in order to delete it
            #!!! race conditions, need to lock file during queries & update
            self._readLockFile()
            if force or self.uid == self.owner:
                self._deleteLockFile()


    def _filename(self):
        """ Get path and filename for edit-lock file. """
        return self.pageobj.getPagePath('edit-lock', isfile=1)


    def _readLockFile(self):
        """ Load lock info if not yet loaded. """
        _ = self._
        self.owner = None
        self.owner_html = wikiutil.escape(_("<unknown>"))
        self.timestamp = 0

        if self.locktype:
            try:
                entry = editlog.EditLog(self.request, filename=self._filename()).next()
            except StopIteration:
                entry = None

            if entry:
                self.owner = entry.userid or entry.addr
                self.owner_html = entry.getEditor(self.request)
                self.timestamp = wikiutil.version2timestamp(entry.ed_time_usecs)


    def _writeLockFile(self):
        """ Write new lock file. """
        self._deleteLockFile()
        try:
            editlog.EditLog(self.request, filename=self._filename(), force_ip=True).add(
               self.request, wikiutil.timestamp2version(self.now), 0, "LOCK", self.page_name)
        except IOError:
            pass

    def _deleteLockFile(self):
        """ Delete the lock file unconditionally. """
        try:
            os.remove(self._filename())
        except OSError:
            pass