WebHelpers / webhelpers / markdown.py

   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
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
#!/usr/bin/env python

# The following constant specifies the name used in the usage
# statement displayed for python versions lower than 2.3.  (With
# python2.3 and higher the usage statement is generated by optparse
# and uses the actual name of the executable called.)

EXECUTABLE_NAME_FOR_USAGE = "python markdown.py"

SPEED_TEST = 0

"""
====================================================================
IF YOA ARE LOOKING TO EXTEND MARKDOWN, SEE THE "FOOTNOTES" SECTION
====================================================================

Python-Markdown
===============

Converts Markdown to HTML.  Basic usage as a module:

    import markdown
    html = markdown.markdown(your_text_string)

Started by [Manfred Stienstra](http://www.dwerg.net/).  Continued and
maintained  by [Yuri Takhteyev](http://www.freewisdom.org).

Project website: http://www.freewisdom.org/projects/python-markdown
Contact: yuri [at] freewisdom.org

License: GPL 2 (http://www.gnu.org/copyleft/gpl.html) or BSD

Version: 1.6a (October 12, 2006)


For changelog, see end of file
"""

import re, sys, os, random, codecs

# set debug level: 3 none, 2 critical, 1 informative, 0 all
(VERBOSE, INFO, CRITICAL, NONE) = range(4)

MESSAGE_THRESHOLD = CRITICAL

def message(level, text) :
    if level >= MESSAGE_THRESHOLD :
        print text


# --------------- CONSTANTS YOU MIGHT WANT TO MODIFY -----------------

# all tabs will be expanded to up to this many spaces
TAB_LENGTH = 4
ENABLE_ATTRIBUTES = 1
SMART_EMPHASIS = 1

# --------------- CONSTANTS YOU _SHOULD NOT_ HAVE TO CHANGE ----------

# a template for html placeholders
HTML_PLACEHOLDER_PREFIX = "qaodmasdkwaspemas"
HTML_PLACEHOLDER = HTML_PLACEHOLDER_PREFIX + "%dajkqlsmdqpakldnzsdfls"

BLOCK_LEVEL_ELEMENTS = ['p', 'div', 'blockquote', 'pre', 'table',
                        'dl', 'ol', 'ul', 'script', 'noscript',
                        'form', 'fieldset', 'iframe', 'math', 'ins',
                        'del', 'hr', 'hr/', 'style']

def is_block_level (tag) :
    return ( (tag in BLOCK_LEVEL_ELEMENTS) or
             (tag[0] == 'h' and tag[1] in "0123456789") )

"""
======================================================================
========================== NANODOM ===================================
======================================================================

The three classes below implement some of the most basic DOM
methods.  I use this instead of minidom because I need a simpler
functionality and do not want to require additional libraries.

Importantly, NanoDom does not do normalization, which is what we
want. It also adds extra white space when converting DOM to string
"""


class Document :

    def appendChild(self, child) :
        self.documentElement = child
        child.parent = self
        self.entities = {}

    def createElement(self, tag, textNode=None) :
        el = Element(tag)
        el.doc = self
        if textNode :
            el.appendChild(self.createTextNode(textNode))
        return el

    def createTextNode(self, text) :
        node = TextNode(text)
        node.doc = self
        return node

    def createEntityReference(self, entity):
        if entity not in self.entities:
            self.entities[entity] = EntityReference(entity)
        return self.entities[entity]

    def toxml (self) :
        return self.documentElement.toxml()

    def normalizeEntities(self, text) :

        pairs = [ ("&", "&"),
                  ("<", "&lt;"),
                  (">", "&gt;"),
                  ("\"", "&quot;")]


        for old, new in pairs :
            text = text.replace(old, new)
        return text

    def find(self, test) :
        return self.documentElement.find(test)

    def unlink(self) :
        self.documentElement.unlink()
        self.documentElement = None


class Element :

    type = "element"

    def __init__ (self, tag) :

        self.nodeName = tag
        self.attributes = []
        self.attribute_values = {}
        self.childNodes = []

    def unlink(self) :
        for child in self.childNodes :
            if child.type == "element" :
                child.unlink()
        self.childNodes = None

    def setAttribute(self, attr, value) :
        if not attr in self.attributes :
            self.attributes.append(attr)

        self.attribute_values[attr] = value

    def insertChild(self, position, child) :
        self.childNodes.insert(position, child)
        child.parent = self

    def removeChild(self, child) :
        self.childNodes.remove(child)

    def replaceChild(self, oldChild, newChild) :
        position = self.childNodes.index(oldChild)
        self.removeChild(oldChild)
        self.insertChild(position, newChild)

    def appendChild(self, child) :
        self.childNodes.append(child)
        child.parent = self

    def handleAttributes(self) :
        pass

    def find(self, test, depth=0) :
        """ Returns a list of descendants that pass the test function """
        matched_nodes = []
        for child in self.childNodes :
            if test(child) :
                matched_nodes.append(child)
            if child.type == "element" :
                matched_nodes += child.find(test, depth+1)
        return matched_nodes

    def toxml(self):
        if ENABLE_ATTRIBUTES :
            for child in self.childNodes:
                child.handleAttributes()
        buffer = ""
        if self.nodeName in ['h1', 'h2', 'h3', 'h4'] :
            buffer += "\n"
        elif self.nodeName in ['li'] :
            buffer += "\n "
        buffer += "<" + self.nodeName
        for attr in self.attributes :
            value = self.attribute_values[attr]
            value = self.doc.normalizeEntities(value)
            buffer += ' %s="%s"' % (attr, value)
        if self.childNodes or self.nodeName in ['blockquote']:
            buffer += ">"
            for child in self.childNodes :
                buffer += child.toxml()
            if self.nodeName == 'p' :
                buffer += "\n"
            elif self.nodeName == 'li' :
                buffer += "\n "
            buffer += "</%s>" % self.nodeName
        else :
            buffer += "/>"
        if self.nodeName in ['p', 'li', 'ul', 'ol',
                             'h1', 'h2', 'h3', 'h4'] :
            buffer += "\n"

        return buffer


class TextNode :

    type = "text"
    attrRegExp = re.compile(r'\{@([^\}]*)=([^\}]*)}') # {@id=123}

    def __init__ (self, text) :
        self.value = text        

    def attributeCallback(self, match) :
        self.parent.setAttribute(match.group(1), match.group(2))

    def handleAttributes(self) :
        self.value = self.attrRegExp.sub(self.attributeCallback, self.value)

    def toxml(self) :
        text = self.value
        if not text.startswith(HTML_PLACEHOLDER_PREFIX):
            if self.parent.nodeName == "p" :
                text = text.replace("\n", "\n   ")
            elif (self.parent.nodeName == "li"
                  and self.parent.childNodes[0]==self):
                text = "\n     " + text.replace("\n", "\n     ")
        text = self.doc.normalizeEntities(text)
        return text


class EntityReference:

    type = "entity_ref"

    def __init__(self, entity):
        self.entity = entity

    def handleAttributes(self):
        pass

    def toxml(self):
        return "&" + self.entity + ";"


"""
======================================================================
========================== PRE-PROCESSORS ============================
======================================================================

Preprocessors munge source text before we start doing anything too
complicated.

Each preprocessor implements a "run" method that takes a pointer to a list of lines of the document,
modifies it as necessary and returns either the same pointer or a
pointer to a new list.  Preprocessors must extend
markdown.Preprocessor.

"""


class Preprocessor :
    pass


class HeaderPreprocessor (Preprocessor):

    """
       Replaces underlined headers with hashed headers to avoid
       the nead for lookahead later.
    """

    def run (self, lines) :

        i = -1
        while i+1 < len(lines) :
            i = i+1
            if not lines[i].strip() :
                continue

            if lines[i].startswith("#") :
                lines.insert(i+1, "\n")

            if (i+1 <= len(lines)
                  and lines[i+1]
                  and lines[i+1][0] in ['-', '=']) :

                underline = lines[i+1].strip()

                if underline == "="*len(underline) :
                    lines[i] = "# " + lines[i].strip()
                    lines[i+1] = ""
                elif underline == "-"*len(underline) :
                    lines[i] = "## " + lines[i].strip()
                    lines[i+1] = ""

        #for l in lines :
        #    print l.encode('utf8')
        #sys.exit(0)

        return lines

HEADER_PREPROCESSOR = HeaderPreprocessor()

class LinePreprocessor (Preprocessor):
    """Deals with HR lines (needs to be done before processing lists)"""

    def run (self, lines) :
        for i in range(len(lines)) :
            if self._isLine(lines[i]) :
                lines[i] = "<hr />"
        return lines

    def _isLine(self, block) :
        """Determines if a block should be replaced with an <HR>"""
        if block.startswith("    ") : return 0  # a code block
        text = "".join([x for x in block if not x.isspace()])
        if len(text) <= 2 :
            return 0
        for pattern in ['isline1', 'isline2', 'isline3'] :
            m = RE.regExp[pattern].match(text)
            if (m and m.group(1)) :
                return 1
        else:
            return 0

LINE_PREPROCESSOR = LinePreprocessor()


class LineBreaksPreprocessor (Preprocessor):
    """Replaces double spaces at the end of the lines with <br/ >."""

    def run (self, lines) :
        for i in range(len(lines)) :
            if (lines[i].endswith("  ")
                and not RE.regExp['tabbed'].match(lines[i]) ):
                lines[i] += "<br />"
        return lines

LINE_BREAKS_PREPROCESSOR = LineBreaksPreprocessor()


class HtmlBlockPreprocessor (Preprocessor):
    """Removes html blocks from self.lines"""
    
    def _get_left_tag(self, block):
        return block[1:].replace(">", " ", 1).split()[0].lower()


    def _get_right_tag(self, left_tag, block):
        return block.rstrip()[-len(left_tag)-2:-1].lower()

    def _equal_tags(self, left_tag, right_tag):
        if left_tag in ['?', '?php', 'div'] : # handle PHP, etc.
            return True
        if ("/" + left_tag) == right_tag:
            return True
        elif left_tag == right_tag[1:] \
            and right_tag[0] != "<":
            return True
        else:
            return False

    def _is_oneliner(self, tag):
        return (tag in ['hr', 'hr/'])

    
    def run (self, lines) :
        new_blocks = []
        text = "\n".join(lines)
        text = text.split("\n\n")
        
        items = []
        left_tag = ''
        right_tag = ''
        in_tag = False # flag
        
        for block in text:
            if block.startswith("\n") :
                block = block[1:]

            if not in_tag:

                if block.startswith("<"):
                    
                    left_tag = self._get_left_tag(block)
                    right_tag = self._get_right_tag(left_tag, block)

                    if not (is_block_level(left_tag) \
                        or block[1] in ["!", "?", "@", "%"]):
                        new_blocks.append(block)
                        continue

                    if self._is_oneliner(left_tag):
                        new_blocks.append(block.strip())
                        continue
                        
                    if block[1] == "!":
                        # is a comment block
                        left_tag = "--"
                        right_tag = self._get_right_tag(left_tag, block)
                        # keep checking conditions below and maybe just append
                        
                    if block.rstrip().endswith(">") \
                        and self._equal_tags(left_tag, right_tag):
                        new_blocks.append(
                            self.stash.store(block.strip()))
                        continue
                    elif not block[1] == "!":
                        # if is block level tag and is not complete
                        items.append(block.strip())
                        in_tag = True
                        continue
                    
                new_blocks.append(block)

            else:
                items.append(block.strip())
                
                right_tag = self._get_right_tag(left_tag, block)
                if self._equal_tags(left_tag, right_tag):
                    # if find closing tag
                    in_tag = False
                    new_blocks.append(
                        self.stash.store('\n\n'.join(items)))
                    items = []
                    
        return "\n\n".join(new_blocks).split("\n")

HTML_BLOCK_PREPROCESSOR = HtmlBlockPreprocessor()


class ReferencePreprocessor (Preprocessor):

    def run (self, lines) :

        new_text = [];
        for line in lines:
            m = RE.regExp['reference-def'].match(line)
            if m:
                id = m.group(2).strip().lower()
                t = m.group(4).strip()  # potential title
                if not t :
                    self.references[id] = (m.group(3), t)
                elif (len(t) >= 2
                      and (t[0] == t[-1] == "\""
                           or t[0] == t[-1] == "\'"
                           or (t[0] == "(" and t[-1] == ")") ) ) :
                    self.references[id] = (m.group(3), t[1:-1])
                else :
                    new_text.append(line)
            else:
                new_text.append(line)

        return new_text #+ "\n"

REFERENCE_PREPROCESSOR = ReferencePreprocessor()

"""
======================================================================
========================== INLINE PATTERNS ===========================
======================================================================

Inline patterns such as *emphasis* are handled by means of auxiliary
objects, one per pattern.  Pattern objects must be instances of classes
that extend markdown.Pattern.  Each pattern object uses a single regular
expression and needs support the following methods:

  pattern.getCompiledRegExp() - returns a regular expression

  pattern.handleMatch(m, doc) - takes a match object and returns
                                a NanoDom node (as a part of the provided
                                doc) or None

All of python markdown's built-in patterns subclass from Patter,
but you can add additional patterns that don't.

Also note that all the regular expressions used by inline must
capture the whole block.  For this reason, they all start with
'^(.*)' and end with '(.*)!'.  In case with built-in expression
Pattern takes care of adding the "^(.*)" and "(.*)!".

Finally, the order in which regular expressions are applied is very
important - e.g. if we first replace http://.../ links with <a> tags
and _then_ try to replace inline html, we would end up with a mess.
So, we apply the expressions in the following order:

       * escape and backticks have to go before everything else, so
         that we can preempt any markdown patterns by escaping them.

       * then we handle auto-links (must be done before inline html)

       * then we handle inline HTML.  At this point we will simply
         replace all inline HTML strings with a placeholder and add
         the actual HTML to a hash.

       * then inline images (must be done before links)

       * then bracketed links, first regular then reference-style

       * finally we apply strong and emphasis
"""

NOBRACKET = r'[^\]\[]*'
BRK = ( r'\[('
        + (NOBRACKET + r'(\['+NOBRACKET)*6
        + (NOBRACKET+ r'\])*'+NOBRACKET)*6
        + NOBRACKET + r')\]' )

BACKTICK_RE = r'\`([^\`]*)\`'                    # `e= m*c^2`
DOUBLE_BACKTICK_RE =  r'\`\`(.*)\`\`'            # ``e=f("`")``
ESCAPE_RE = r'\\(.)'                             # \<
EMPHASIS_RE = r'\*([^\*]*)\*'                    # *emphasis*
STRONG_RE = r'\*\*(.*)\*\*'                      # **strong**
STRONG_EM_RE = r'\*\*\*([^_]*)\*\*\*'            # ***strong***

if SMART_EMPHASIS:
    EMPHASIS_2_RE = r'(?<!\S)_(\S[^_]*)_'        # _emphasis_
else :
    EMPHASIS_2_RE = r'_([^_]*)_'                 # _emphasis_

STRONG_2_RE = r'__([^_]*)__'                     # __strong__
STRONG_EM_2_RE = r'___([^_]*)___'                # ___strong___

LINK_RE = BRK + r'\s*\(([^\)]*)\)'               # [text](url)
LINK_ANGLED_RE = BRK + r'\s*\(<([^\)]*)>\)'      # [text](<url>)
IMAGE_LINK_RE = r'\!' + BRK + r'\s*\(([^\)]*)\)' # ![alttxt](http://x.com/)
REFERENCE_RE = BRK+ r'\s*\[([^\]]*)\]'           # [Google][3]
IMAGE_REFERENCE_RE = r'\!' + BRK + '\s*\[([^\]]*)\]' # ![alt text][2]
NOT_STRONG_RE = r'( \* )'                        # stand-alone * or _
AUTOLINK_RE = r'<(http://[^>]*)>'                # <http://www.123.com>
AUTOMAIL_RE = r'<([^> \!]*@[^> ]*)>'               # <me@example.com>
#HTML_RE = r'(\<[^\>]*\>)'                        # <...>
HTML_RE = r'(\<[a-zA-Z/][^\>]*\>)'               # <...>
ENTITY_RE = r'(&[\#a-zA-Z0-9]*;)'                # &amp;

class Pattern:

    def __init__ (self, pattern) :
        self.pattern = pattern
        self.compiled_re = re.compile("^(.*)%s(.*)$" % pattern, re.DOTALL)

    def getCompiledRegExp (self) :
        return self.compiled_re

BasePattern = Pattern # for backward compatibility

class SimpleTextPattern (Pattern) :

    def handleMatch(self, m, doc) :
        return doc.createTextNode(m.group(2))

class SimpleTagPattern (Pattern):

    def __init__ (self, pattern, tag) :
        Pattern.__init__(self, pattern)
        self.tag = tag

    def handleMatch(self, m, doc) :
        el = doc.createElement(self.tag)
        el.appendChild(doc.createTextNode(m.group(2)))
        return el

class BacktickPattern (Pattern):

    def __init__ (self, pattern):
        Pattern.__init__(self, pattern)
        self.tag = "code"

    def handleMatch(self, m, doc) :
        el = doc.createElement(self.tag)
        text = m.group(2).strip()
        #text = text.replace("&", "&amp;")
        el.appendChild(doc.createTextNode(text))
        return el


class DoubleTagPattern (SimpleTagPattern) :

    def handleMatch(self, m, doc) :
        tag1, tag2 = self.tag.split(",")
        el1 = doc.createElement(tag1)
        el2 = doc.createElement(tag2)
        el1.appendChild(el2)
        el2.appendChild(doc.createTextNode(m.group(2)))
        return el1


class HtmlPattern (Pattern):

    def handleMatch (self, m, doc) :
        place_holder = self.stash.store(m.group(2))
        return doc.createTextNode(place_holder)


class LinkPattern (Pattern):

    def handleMatch(self, m, doc) :
        el = doc.createElement('a')
        el.appendChild(doc.createTextNode(m.group(2)))
        parts = m.group(9).split()
        # We should now have [], [href], or [href, title]
        if parts :
            el.setAttribute('href', parts[0])
        else :
            el.setAttribute('href', "")
        if len(parts) > 1 :
            # we also got a title
            title = " ".join(parts[1:]).strip()
            title = dequote(title) #.replace('"', "&quot;")
            el.setAttribute('title', title)
        return el


class ImagePattern (Pattern):

    def handleMatch(self, m, doc):
        el = doc.createElement('img')
        src_parts = m.group(9).split()
        el.setAttribute('src', src_parts[0])
        if len(src_parts) > 1 :
            el.setAttribute('title', dequote(" ".join(src_parts[1:])))
        if ENABLE_ATTRIBUTES :
            text = doc.createTextNode(m.group(2))
            el.appendChild(text)
            text.handleAttributes()
            truealt = text.value
            el.childNodes.remove(text)
        else:
            truealt = m.group(2)
        el.setAttribute('alt', truealt)
        return el

class ReferencePattern (Pattern):

    def handleMatch(self, m, doc):
        if m.group(9) :
            id = m.group(9).lower()
        else :
            # if we got something like "[Google][]"
            # we'll use "google" as the id
            id = m.group(2).lower()
        if not self.references.has_key(id) : # ignore undefined refs
            return None
        href, title = self.references[id]
        text = m.group(2)
        return self.makeTag(href, title, text, doc)

    def makeTag(self, href, title, text, doc):
        el = doc.createElement('a')
        el.setAttribute('href', href)
        if title :
            el.setAttribute('title', title)
        el.appendChild(doc.createTextNode(text))
        return el


class ImageReferencePattern (ReferencePattern):

    def makeTag(self, href, title, text, doc):
        el = doc.createElement('img')
        el.setAttribute('src', href)
        if title :
            el.setAttribute('title', title)
        el.setAttribute('alt', text)
        return el


class AutolinkPattern (Pattern):

    def handleMatch(self, m, doc):
        el = doc.createElement('a')
        el.setAttribute('href', m.group(2))
        el.appendChild(doc.createTextNode(m.group(2)))
        return el

class AutomailPattern (Pattern):

    def handleMatch(self, m, doc) :
        el = doc.createElement('a')
        email = m.group(2)
        if email.startswith("mailto:"):
            email = email[len("mailto:"):]
        for letter in email:
            entity = doc.createEntityReference("#%d" % ord(letter))
            el.appendChild(entity)
        mailto = "mailto:" + email
        mailto = "".join(['&#%d;' % ord(letter) for letter in mailto])
        el.setAttribute('href', mailto)
        return el

ESCAPE_PATTERN          = SimpleTextPattern(ESCAPE_RE)
NOT_STRONG_PATTERN      = SimpleTextPattern(NOT_STRONG_RE)

BACKTICK_PATTERN        = BacktickPattern(BACKTICK_RE)
DOUBLE_BACKTICK_PATTERN = BacktickPattern(DOUBLE_BACKTICK_RE)
STRONG_PATTERN          = SimpleTagPattern(STRONG_RE, 'strong')
STRONG_PATTERN_2        = SimpleTagPattern(STRONG_2_RE, 'strong')
EMPHASIS_PATTERN        = SimpleTagPattern(EMPHASIS_RE, 'em')
EMPHASIS_PATTERN_2      = SimpleTagPattern(EMPHASIS_2_RE, 'em')

STRONG_EM_PATTERN       = DoubleTagPattern(STRONG_EM_RE, 'strong,em')
STRONG_EM_PATTERN_2     = DoubleTagPattern(STRONG_EM_2_RE, 'strong,em')

LINK_PATTERN            = LinkPattern(LINK_RE)
LINK_ANGLED_PATTERN     = LinkPattern(LINK_ANGLED_RE)
IMAGE_LINK_PATTERN      = ImagePattern(IMAGE_LINK_RE)
IMAGE_REFERENCE_PATTERN = ImageReferencePattern(IMAGE_REFERENCE_RE)
REFERENCE_PATTERN       = ReferencePattern(REFERENCE_RE)

HTML_PATTERN            = HtmlPattern(HTML_RE)
ENTITY_PATTERN          = HtmlPattern(ENTITY_RE)

AUTOLINK_PATTERN        = AutolinkPattern(AUTOLINK_RE)
AUTOMAIL_PATTERN        = AutomailPattern(AUTOMAIL_RE)


"""
======================================================================
========================== POST-PROCESSORS ===========================
======================================================================

Markdown also allows post-processors, which are similar to
preprocessors in that they need to implement a "run" method.  Unlike
pre-processors, they take a NanoDom document as a parameter and work
with that.

Post-Processor should extend markdown.Postprocessor.

There are currently no standard post-processors, but the footnote
extension below uses one.
"""

class Postprocessor :
    pass


"""
======================================================================
========================== MISC AUXILIARY CLASSES ====================
======================================================================
"""

class HtmlStash :
    """This class is used for stashing HTML objects that we extract
        in the beginning and replace with place-holders."""

    def __init__ (self) :
        self.html_counter = 0 # for counting inline html segments
        self.rawHtmlBlocks=[]

    def store(self, html) :
        """Saves an HTML segment for later reinsertion.  Returns a
           placeholder string that needs to be inserted into the
           document.

           @param html: an html segment
           @returns : a placeholder string """
        self.rawHtmlBlocks.append(html)
        placeholder = HTML_PLACEHOLDER % self.html_counter
        self.html_counter += 1
        return placeholder


class BlockGuru :

    def _findHead(self, lines, fn, allowBlank=0) :

        """Functional magic to help determine boundaries of indented
           blocks.

           @param lines: an array of strings
           @param fn: a function that returns a substring of a string
                      if the string matches the necessary criteria
           @param allowBlank: specifies whether it's ok to have blank
                      lines between matching functions
           @returns: a list of post processes items and the unused
                      remainder of the original list"""

        items = []
        item = -1

        i = 0 # to keep track of where we are

        for line in lines :

            if not line.strip() and not allowBlank:
                return items, lines[i:]

            if not line.strip() and allowBlank:
                # If we see a blank line, this _might_ be the end
                i += 1

                # Find the next non-blank line
                for j in range(i, len(lines)) :
                    if lines[j].strip() :
                        next = lines[j]
                        break
                else :
                    # There is no more text => this is the end
                    break

                # Check if the next non-blank line is still a part of the list

                part = fn(next)

                if part :
                    items.append("")
                    continue
                else :
                    break # found end of the list

            part = fn(line)

            if part :
                items.append(part)
                i += 1
                continue
            else :
                return items, lines[i:]
        else :
            i += 1

        return items, lines[i:]


    def detabbed_fn(self, line) :
        """ An auxiliary method to be passed to _findHead """
        m = RE.regExp['tabbed'].match(line)
        if m:
            return m.group(4)
        else :
            return None


    def detectTabbed(self, lines) :

        return self._findHead(lines, self.detabbed_fn,
                              allowBlank = 1)


def print_error(string):
    """Print an error string to stderr"""
    sys.stderr.write(string +'\n')


def dequote(string) :
    """ Removes quotes from around a string """
    if ( ( string.startswith('"') and string.endswith('"'))
         or (string.startswith("'") and string.endswith("'")) ) :
        return string[1:-1]
    else :
        return string

"""
======================================================================
========================== CORE MARKDOWN =============================
======================================================================

This stuff is ugly, so if you are thinking of extending the syntax,
see first if you can do it via pre-processors, post-processors,
inline patterns or a combination of the three.
"""

class CorePatterns :
    """This class is scheduled for removal as part of a refactoring
        effort."""

    patterns = {
        'header':          r'(#*)([^#]*)(#*)', # # A title
        'reference-def' :  r'(\ ?\ ?\ ?)\[([^\]]*)\]:\s*([^ ]*)(.*)',
                           # [Google]: http://www.google.com/
        'containsline':    r'([-]*)$|^([=]*)', # -----, =====, etc.
        'ol':              r'[ ]{0,3}[\d]*\.\s+(.*)', # 1. text
        'ul':              r'[ ]{0,3}[*+-]\s+(.*)', # "* text"
        'isline1':         r'(\**)', # ***
        'isline2':         r'(\-*)', # ---
        'isline3':         r'(\_*)', # ___
        'tabbed':          r'((\t)|(    ))(.*)', # an indented line
        'quoted' :         r'> ?(.*)', # a quoted block ("> ...")
    }

    def __init__ (self) :

        self.regExp = {}
        for key in self.patterns.keys() :
            self.regExp[key] = re.compile("^%s$" % self.patterns[key],
                                          re.DOTALL)

        self.regExp['containsline'] = re.compile(r'^([-]*)$|^([=]*)$', re.M)

RE = CorePatterns()


class Markdown:
    """ Markdown formatter class for creating an html document from
        Markdown text """


    def __init__(self, source=None,
                 extensions=[],
                 extension_configs=None,
                 encoding=None,
                 safe_mode = True):
        """Creates a new Markdown instance.

           @param source: The text in Markdown format.
           @param encoding: The character encoding of <text>. """

        self.safeMode = safe_mode
        self.encoding = encoding
        self.source = source
        self.blockGuru = BlockGuru()
        self.registeredExtensions = []
        self.stripTopLevelTags = 1
        self.docType = ""

        self.preprocessors = [ HEADER_PREPROCESSOR,
                               LINE_PREPROCESSOR,
                               HTML_BLOCK_PREPROCESSOR,
                               LINE_BREAKS_PREPROCESSOR,
                               # A footnote preprocessor will
                               # get inserted here
                               REFERENCE_PREPROCESSOR ]


        self.postprocessors = [] # a footnote postprocessor will get
                                 # inserted later

        self.textPostprocessors = [] # a footnote postprocessor will get
                                     # inserted later                                 

        self.prePatterns = []
        

        self.inlinePatterns = [ DOUBLE_BACKTICK_PATTERN,
                                BACKTICK_PATTERN,
                                ESCAPE_PATTERN,
                                IMAGE_LINK_PATTERN,
                                IMAGE_REFERENCE_PATTERN,
                                REFERENCE_PATTERN,
                                LINK_ANGLED_PATTERN,
                                LINK_PATTERN,
                                AUTOLINK_PATTERN,
                                AUTOMAIL_PATTERN,
                                HTML_PATTERN,
                                ENTITY_PATTERN,
                                NOT_STRONG_PATTERN,
                                STRONG_EM_PATTERN,
                                STRONG_EM_PATTERN_2,
                                STRONG_PATTERN,
                                STRONG_PATTERN_2,
                                EMPHASIS_PATTERN,
                                EMPHASIS_PATTERN_2
                                # The order of the handlers matters!!!
                                ]

        self.registerExtensions(extensions = extensions,
                                configs = extension_configs)

        self.reset()


    def registerExtensions(self, extensions, configs) :

        if not configs :
            configs = {}

        for ext in extensions :

            extension_module_name = "mdx_" + ext

            try :
                module = __import__(extension_module_name)

            except :
                message(CRITICAL,
                        "couldn't load extension %s (looking for %s module)"
                        % (ext, extension_module_name) )
            else :

                if configs.has_key(ext) :
                    configs_for_ext = configs[ext]
                else :
                    configs_for_ext = []
                extension = module.makeExtension(configs_for_ext)    
                extension.extendMarkdown(self, globals())




    def registerExtension(self, extension) :
        """ This gets called by the extension """
        self.registeredExtensions.append(extension)

    def reset(self) :
        """Resets all state variables so that we can start
            with a new text."""
        self.references={}
        self.htmlStash = HtmlStash()

        HTML_BLOCK_PREPROCESSOR.stash = self.htmlStash
        REFERENCE_PREPROCESSOR.references = self.references
        HTML_PATTERN.stash = self.htmlStash
        ENTITY_PATTERN.stash = self.htmlStash
        REFERENCE_PATTERN.references = self.references
        IMAGE_REFERENCE_PATTERN.references = self.references

        for extension in self.registeredExtensions :
            extension.reset()


    def _transform(self):
        """Transforms the Markdown text into a XHTML body document

           @returns: A NanoDom Document """

        # Setup the document

        self.doc = Document()
        self.top_element = self.doc.createElement("span")
        self.top_element.appendChild(self.doc.createTextNode('\n'))
        self.top_element.setAttribute('class', 'markdown')
        self.doc.appendChild(self.top_element)

        # Fixup the source text
        text = self.source.strip()
        text = text.replace("\r\n", "\n").replace("\r", "\n")
        text += "\n\n"
        text = text.expandtabs(TAB_LENGTH)

        # Split into lines and run the preprocessors that will work with
        # self.lines

        self.lines = text.split("\n")

        # Run the pre-processors on the lines
        for prep in self.preprocessors :
            self.lines = prep.run(self.lines)

        # Create a NanoDom tree from the lines and attach it to Document


        buffer = []
        for line in self.lines :
            if line.startswith("#") :
                self._processSection(self.top_element, buffer)
                buffer = [line]
            else :
                buffer.append(line)
        self._processSection(self.top_element, buffer)
        
        #self._processSection(self.top_element, self.lines)

        # Not sure why I put this in but let's leave it for now.
        self.top_element.appendChild(self.doc.createTextNode('\n'))

        # Run the post-processors
        for postprocessor in self.postprocessors :
            postprocessor.run(self.doc)

        return self.doc


    def _processSection(self, parent_elem, lines,
                        inList = 0, looseList = 0) :

        """Process a section of a source document, looking for high
           level structural elements like lists, block quotes, code
           segments, html blocks, etc.  Some those then get stripped
           of their high level markup (e.g. get unindented) and the
           lower-level markup is processed recursively.

           @param parent_elem: A NanoDom element to which the content
                               will be added
           @param lines: a list of lines
           @param inList: a level
           @returns: None"""

        if not lines :
            return

        # Check if this section starts with a list, a blockquote or
        # a code block

        processFn = { 'ul' :     self._processUList,
                      'ol' :     self._processOList,
                      'quoted' : self._processQuote,
                      'tabbed' : self._processCodeBlock }

        for regexp in ['ul', 'ol', 'quoted', 'tabbed'] :
            m = RE.regExp[regexp].match(lines[0])
            if m :
                processFn[regexp](parent_elem, lines, inList)
                return

        # We are NOT looking at one of the high-level structures like
        # lists or blockquotes.  So, it's just a regular paragraph
        # (though perhaps nested inside a list or something else).  If
        # we are NOT inside a list, we just need to look for a blank
        # line to find the end of the block.  If we ARE inside a
        # list, however, we need to consider that a sublist does not
        # need to be separated by a blank line.  Rather, the following
        # markup is legal:
        #
        # * The top level list item
        #
        #     Another paragraph of the list.  This is where we are now.
        #     * Underneath we might have a sublist.
        #

        if inList :

            start, theRest = self._linesUntil(lines, (lambda line:
                             RE.regExp['ul'].match(line)
                             or RE.regExp['ol'].match(line)
                                              or not line.strip()))

            self._processSection(parent_elem, start,
                                 inList - 1, looseList = looseList)
            self._processSection(parent_elem, theRest,
                                 inList - 1, looseList = looseList)


        else : # Ok, so it's just a simple block

            paragraph, theRest = self._linesUntil(lines, lambda line:
                                                 not line.strip())

            if len(paragraph) and paragraph[0].startswith('#') :
                m = RE.regExp['header'].match(paragraph[0])
                if m :
                    level = len(m.group(1))
                    h = self.doc.createElement("h%d" % level)
                    parent_elem.appendChild(h)
                    for item in self._handleInlineWrapper2(m.group(2).strip()) :
                        h.appendChild(item)
                else :
                    message(CRITICAL, "We've got a problem header!")

            elif paragraph :

                list = self._handleInlineWrapper2("\n".join(paragraph))

                if ( parent_elem.nodeName == 'li'
                     and not (looseList or parent_elem.childNodes)):

                    #and not parent_elem.childNodes) :
                    # If this is the first paragraph inside "li", don't
                    # put <p> around it - append the paragraph bits directly
                    # onto parent_elem
                    el = parent_elem
                else :
                    # Otherwise make a "p" element
                    el = self.doc.createElement("p")
                    parent_elem.appendChild(el)

                for item in list :
                    el.appendChild(item)

            if theRest :
                theRest = theRest[1:]  # skip the first (blank) line

            self._processSection(parent_elem, theRest, inList)



    def _processUList(self, parent_elem, lines, inList) :
        self._processList(parent_elem, lines, inList,
                         listexpr='ul', tag = 'ul')

    def _processOList(self, parent_elem, lines, inList) :
        self._processList(parent_elem, lines, inList,
                         listexpr='ol', tag = 'ol')


    def _processList(self, parent_elem, lines, inList, listexpr, tag) :
        """Given a list of document lines starting with a list item,
           finds the end of the list, breaks it up, and recursively
           processes each list item and the remainder of the text file.

           @param parent_elem: A dom element to which the content will be added
           @param lines: a list of lines
           @param inList: a level
           @returns: None"""

        ul = self.doc.createElement(tag)  # ul might actually be '<ol>'
        parent_elem.appendChild(ul)

        looseList = 0

        # Make a list of list items
        items = []
        item = -1

        i = 0  # a counter to keep track of where we are

        for line in lines :

            loose = 0
            if not line.strip() :
                # If we see a blank line, this _might_ be the end of the list
                i += 1
                loose = 1

                # Find the next non-blank line
                for j in range(i, len(lines)) :
                    if lines[j].strip() :
                        next = lines[j]
                        break
                else :
                    # There is no more text => end of the list
                    break

                # Check if the next non-blank line is still a part of the list
                if ( RE.regExp['ul'].match(next) or
                     RE.regExp['ol'].match(next) or 
                     RE.regExp['tabbed'].match(next) ):
                    # get rid of any white space in the line
                    items[item].append(line.strip())
                    looseList = loose or looseList
                    continue
                else :
                    break # found end of the list

            # Now we need to detect list items (at the current level)
            # while also detabing child elements if necessary

            for expr in ['ul', 'ol', 'tabbed']:

                m = RE.regExp[expr].match(line)
                if m :
                    if expr in ['ul', 'ol'] :  # We are looking at a new item
                        if m.group(1) :
                            items.append([m.group(1)])
                            item += 1
                    elif expr == 'tabbed' :  # This line needs to be detabbed
                        items[item].append(m.group(4)) #after the 'tab'

                    i += 1
                    break
            else :
                items[item].append(line)  # Just regular continuation
                i += 1 # added on 2006.02.25
        else :
            i += 1

        # Add the dom elements
        for item in items :
            li = self.doc.createElement("li")
            ul.appendChild(li)

            self._processSection(li, item, inList + 1, looseList = looseList)

        # Process the remaining part of the section

        self._processSection(parent_elem, lines[i:], inList)


    def _linesUntil(self, lines, condition) :
        """ A utility function to break a list of lines upon the
            first line that satisfied a condition.  The condition
            argument should be a predicate function.
            """

        i = -1
        for line in lines :
            i += 1
            if condition(line) : break
        else :
            i += 1
        return lines[:i], lines[i:]

    def _processQuote(self, parent_elem, lines, inList) :
        """Given a list of document lines starting with a quote finds
           the end of the quote, unindents it and recursively
           processes the body of the quote and the remainder of the
           text file.

           @param parent_elem: DOM element to which the content will be added
           @param lines: a list of lines
           @param inList: a level
           @returns: None """

        dequoted = []
        i = 0
        for line in lines :
            m = RE.regExp['quoted'].match(line)
            if m :
                dequoted.append(m.group(1))
                i += 1
            else :
                break
        else :
            i += 1

        blockquote = self.doc.createElement('blockquote')
        parent_elem.appendChild(blockquote)

        self._processSection(blockquote, dequoted, inList)
        self._processSection(parent_elem, lines[i:], inList)




    def _processCodeBlock(self, parent_elem, lines, inList) :
        """Given a list of document lines starting with a code block
           finds the end of the block, puts it into the dom verbatim
           wrapped in ("<pre><code>") and recursively processes the
           the remainder of the text file.

           @param parent_elem: DOM element to which the content will be added
           @param lines: a list of lines
           @param inList: a level
           @returns: None"""

        detabbed, theRest = self.blockGuru.detectTabbed(lines)

        pre = self.doc.createElement('pre')
        code = self.doc.createElement('code')
        parent_elem.appendChild(pre)
        pre.appendChild(code)
        text = "\n".join(detabbed).rstrip()+"\n"
        #text = text.replace("&", "&amp;")
        code.appendChild(self.doc.createTextNode(text))
        self._processSection(parent_elem, theRest, inList)


    def _handleInlineWrapper2 (self, line) :


        parts = [line]

        #if not(line):
        #    return [self.doc.createTextNode(' ')]

        for pattern in self.inlinePatterns :

            #print
            #print self.inlinePatterns.index(pattern)

            i = 0

            #print parts
            while i < len(parts) :
                
                x = parts[i]
                #print i
                if isinstance(x, (str, unicode)) :
                    result = self._applyPattern(x, pattern)
                    #print result
                    #print result
                    #print parts, i
                    if result :
                        i -= 1
                        parts.remove(x)
                        for y in result :
                            parts.insert(i+1,y)
                
                i += 1

        for i in range(len(parts)) :
            x = parts[i]
            if isinstance(x, (str, unicode)) :
                parts[i] = self.doc.createTextNode(x)

        return parts
        


    def _handleInlineWrapper (self, line) :

        # A wrapper around _handleInline to avoid recursion

        parts = [line]

        i = 0
        
        while i < len(parts) :
            x = parts[i]
            if isinstance(x, (str, unicode)) :
                parts.remove(x)
                result = self._handleInline(x)
                for y in result :
                    parts.insert(i,y)
            else :
                i += 1

        return parts

    def _handleInline(self,  line):
        """Transform a Markdown line with inline elements to an XHTML
        fragment.

        This function uses auxiliary objects called inline patterns.
        See notes on inline patterns above.

        @param item: A block of Markdown text
        @return: A list of NanoDom nodes """

        if not(line):
            return [self.doc.createTextNode(' ')]

        for pattern in self.inlinePatterns :
            list = self._applyPattern( line, pattern)
            if list: return list

        return [self.doc.createTextNode(line)]

    def _applyPattern(self, line, pattern) :
        """ Given a pattern name, this function checks if the line
        fits the pattern, creates the necessary elements, and returns
        back a list consisting of NanoDom elements and/or strings.
        
        @param line: the text to be processed
        @param pattern: the pattern to be checked

        @returns: the appropriate newly created NanoDom element if the
                  pattern matches, None otherwise.
        """

        # match the line to pattern's pre-compiled reg exp.
        # if no match, move on.

        m = pattern.getCompiledRegExp().match(line)
        if not m :
            return None

        # if we got a match let the pattern make us a NanoDom node
        # if it doesn't, move on
        node = pattern.handleMatch(m, self.doc)

        if node :
            # Those are in the reverse order!
            return ( m.groups()[-1], # the string to the left
                     node,           # the new node
                     m.group(1))     # the string to the right of the match

        else :
            return None

    def __str__(self, source = None):
        """Return the document in XHTML format.

        @returns: A serialized XHTML body."""
        #try :

        if source :
            self.source = source
        
        doc = self._transform()
        xml = doc.toxml()

        #finally:
        #    doc.unlink()

        # Let's stick in all the raw html pieces

        for i in range(self.htmlStash.html_counter) :
            html = self.htmlStash.rawHtmlBlocks[i]
            if self.safeMode :
                html = "[HTML_REMOVED]"
                
            xml = xml.replace("<p>%s\n</p>" % (HTML_PLACEHOLDER % i),
                              html + "\n")
            xml = xml.replace(HTML_PLACEHOLDER % i,
                              html)

        # And return everything but the top level tag

        if self.stripTopLevelTags :
            xml = xml.strip()[23:-7] + "\n"

        for pp in self.textPostprocessors :
            xml = pp.run(xml)

        return self.docType + xml


    toString = __str__


    def __unicode__(self):
        """Return the document in XHTML format as a Unicode object.
        """
        return str(self)#.decode(self.encoding)


    toUnicode = __unicode__




# ====================================================================

def markdownFromFile(input = None,
                     output = None,
                     extensions = [],
                     encoding = None,
                     message_threshold = CRITICAL,
                     safe = False) :

    global MESSAGE_THRESHOLD
    MESSAGE_THRESHOLD = message_threshold

    message(VERBOSE, "input file: %s" % input)


    if not encoding :
        encoding = "utf-8"

    input_file = codecs.open(input, mode="r", encoding="utf-8")
    text = input_file.read()
    input_file.close()

    new_text = markdown(text, extensions, encoding, safe_mode = safe)

    if output :
        output_file = codecs.open(output, "w", encoding=encoding)
        output_file.write(new_text)
        output_file.close()

    else :
        sys.stdout.write(new_text.encode(encoding))

def markdown(text,
             extensions = [],
             encoding = None,
             safe_mode = False) :
    
    message(VERBOSE, "in markdown.markdown(), received text:\n%s" % text)

    extension_names = []
    extension_configs = {}
    
    for ext in extensions :
        pos = ext.find("(") 
        if pos == -1 :
            extension_names.append(ext)
        else :
            name = ext[:pos]
            extension_names.append(name)
            pairs = [x.split("=") for x in ext[pos+1:-1].split(",")]
            configs = [(x.strip(), y.strip()) for (x, y) in pairs]
            extension_configs[name] = configs
            #print configs

    md = Markdown(text, extensions=extension_names,
                  extension_configs=extension_configs,
                  safe_mode = safe_mode)

    return md.toString()
        

class Extension :

    def __init__(self, configs = {}) :
        self.config = configs

    def getConfig(self, key) :
        if self.config.has_key(key) :
            #print self.config[key][0]
            return self.config[key][0]
        else :
            return ""

    def getConfigInfo(self) :
        return [(key, self.config[key][1]) for key in self.config.keys()]

    def setConfig(self, key, value) :
        self.config[key][0] = value


OPTPARSE_WARNING = """
Python 2.3 or higher required for advanced command line options.
For lower versions of Python use:

      %s INPUT_FILE > OUTPUT_FILE
    
""" % EXECUTABLE_NAME_FOR_USAGE

def parse_options() :

    try :
        optparse = __import__("optparse")
    except :
        if len(sys.argv) == 2 :
            return {'input' : sys.argv[1],
                    'output' : None,
                    'message_threshold' : CRITICAL,
                    'safe' : False,
                    'extensions' : [],
                    'encoding' : None }

        else :
            print OPTPARSE_WARNING
            return None

    parser = optparse.OptionParser(usage="%prog INPUTFILE [options]")

    parser.add_option("-f", "--file", dest="filename",
                      help="write output to OUTPUT_FILE",
                      metavar="OUTPUT_FILE")
    parser.add_option("-e", "--encoding", dest="encoding",
                      help="encoding for input and output files",)
    parser.add_option("-q", "--quiet", default = CRITICAL,
                      action="store_const", const=NONE, dest="verbose",
                      help="suppress all messages")
    parser.add_option("-v", "--verbose",
                      action="store_const", const=INFO, dest="verbose",
                      help="print info messages")
    parser.add_option("-s", "--safe",
                      action="store_const", const=True, dest="safe",
                      help="same mode (strip user's HTML tag)")
    
    parser.add_option("--noisy",
                      action="store_const", const=VERBOSE, dest="verbose",
                      help="print debug messages")
    parser.add_option("-x", "--extension", action="append", dest="extensions",
                      help = "load extension EXTENSION", metavar="EXTENSION")

    (options, args) = parser.parse_args()

    if not len(args) == 1 :
        parser.print_help()
        return None
    else :
        input_file = args[0]

    if not options.extensions :
        options.extensions = []

    return {'input' : input_file,
            'output' : options.filename,
            'message_threshold' : options.verbose,
            'safe' : options.safe,
            'extensions' : options.extensions,
            'encoding' : options.encoding }

if __name__ == '__main__':
    """ Run Markdown from the command line. """

    options = parse_options()

    #if os.access(inFile, os.R_OK):

    if not options :
        sys.exit(0)
    
    markdownFromFile(**options)
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.