cpython/Lib/HTMLParser.py at 2.7 · python-emscripten/cpython · GitHub

Repository navigation

History

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

"""A parser for HTML and XHTML."""

# This file is based on sgmllib.py, but the API is slightly different.

# XXX There should be a way to distinguish between PCDATA (parsed

# character data -- the normal case), RCDATA (replaceable character

# data -- only char and entity references and end tags are special)

# and CDATA (character data -- only end tags are special).

import markupbase

import re

# Regular expressions used for parsing

interesting_normal = re.compile('[&<]')

incomplete = re.compile('&[a-zA-Z#]')

entityref = re.compile('&([a-zA-Z][-.a-zA-Z0-9]*)[^a-zA-Z0-9]')

charref = re.compile('&#(?:[0-9]+|[xX][0-9a-fA-F]+)[^0-9a-fA-F]')

starttagopen = re.compile('<[a-zA-Z]')

piclose = re.compile('>')

commentclose = re.compile(r'--\s*>')

# see http://www.w3.org/TR/html5/tokenization.html#tag-open-state

# and http://www.w3.org/TR/html5/tokenization.html#tag-name-state

# note: if you change tagfind/attrfind remember to update locatestarttagend too

tagfind = re.compile('([a-zA-Z][^\t\n\r\f />\x00]*)(?:\s|/(?!>))*')

# this regex is currently unused, but left for backward compatibility

tagfind_tolerant = re.compile('[a-zA-Z][^\t\n\r\f />\x00]*')

attrfind = re.compile(

r'((?<=[\'"\s/])[^\s/>][^\s/=>]*)(\s*=+\s*'

r'(\'[^\']*\'|"[^"]*"|(?![\'"])[^>\s]*))?(?:\s|/(?!>))*')

locatestarttagend = re.compile(r"""

<[a-zA-Z][^\t\n\r\f />\x00]* # tag name

(?:[\s/]* # optional whitespace before attribute name

(?:(?<=['"\s/])[^\s/>][^\s/=>]* # attribute name

(?:\s*=+\s* # value indicator

(?:'[^']*' # LITA-enclosed value

|"[^"]*" # LIT-enclosed value

|(?!['"])[^>\s]* # bare value

)

)?(?:\s|/(?!>))*

\s* # trailing whitespace

""", re.VERBOSE)

endendtag = re.compile('>')

# the HTML 5 spec, section 8.1.2.2, doesn't allow spaces between

# </ and the tag name, so maybe this should be fixed

endtagfind = re.compile('</\s*([a-zA-Z][-.a-zA-Z0-9:_]*)\s*>')

class HTMLParseError(Exception):

"""Exception raised for all parse errors."""

def __init__(self, msg, position=(None, None)):

assert msg

self.msg = msg

self.lineno = position[0]

self.offset = position[1]

def __str__(self):

result = self.msg

if self.lineno is not None:

result = result + ", at line %d" % self.lineno

if self.offset is not None:

result = result + ", column %d" % (self.offset + 1)

return result

class HTMLParser(markupbase.ParserBase):

"""Find tags and other markup and call handler functions.

Usage:

p = HTMLParser()

p.feed(data)

...

p.close()

Start tags are handled by calling self.handle_starttag() or

self.handle_startendtag(); end tags by self.handle_endtag(). The

data between tags is passed from the parser to the derived class

by calling self.handle_data() with the data as argument (the data

may be split up in arbitrary chunks). Entity references are

passed by calling self.handle_entityref() with the entity

reference as the argument. Numeric character references are

passed to self.handle_charref() with the string containing the

reference as the argument.

"""

CDATA_CONTENT_ELEMENTS = ("script", "style")

def __init__(self):

"""Initialize and reset this instance."""

self.reset()

def reset(self):

"""Reset this instance. Loses all unprocessed data."""

self.rawdata = ''

self.lasttag = '???'

self.interesting = interesting_normal

self.cdata_elem = None

markupbase.ParserBase.reset(self)

def feed(self, data):

r"""Feed data to the parser.

Call this as often as you want, with as little or as much text

as you want (may include '\n').

"""

self.rawdata = self.rawdata + data

self.goahead(0)

def close(self):

"""Handle any buffered data."""

self.goahead(1)

def error(self, message):

raise HTMLParseError(message, self.getpos())

__starttag_text = None

def get_starttag_text(self):

"""Return full source of start tag: '<...>'."""

return self.__starttag_text

def set_cdata_mode(self, elem):

self.cdata_elem = elem.lower()

self.interesting = re.compile(r'</\s*%s\s*>' % self.cdata_elem, re.I)

def clear_cdata_mode(self):

self.interesting = interesting_normal

self.cdata_elem = None

# Internal -- handle data as far as reasonable. May leave state

# and data to be processed by a subsequent call. If 'end' is

# true, force handling all data as if followed by EOF marker.

def goahead(self, end):

rawdata = self.rawdata

i = 0

n = len(rawdata)

while i < n:

match = self.interesting.search(rawdata, i) # < or &

if match:

j = match.start()

else:

if self.cdata_elem:

break

j = n

if i < j: self.handle_data(rawdata[i:j])

i = self.updatepos(i, j)

if i == n: break

startswith = rawdata.startswith

if startswith('<', i):

if starttagopen.match(rawdata, i): # < + letter

k = self.parse_starttag(i)

elif startswith("</", i):

k = self.parse_endtag(i)

elif startswith("<!--", i):

k = self.parse_comment(i)

elif startswith("<?", i):

k = self.parse_pi(i)

elif startswith("<!", i):

k = self.parse_html_declaration(i)

elif (i + 1) < n:

self.handle_data("<")

k = i + 1

else:

break

if k < 0:

if not end:

break

k = rawdata.find('>', i + 1)

if k < 0:

k = rawdata.find('<', i + 1)

if k < 0:

k = i + 1

else:

k += 1

self.handle_data(rawdata[i:k])

i = self.updatepos(i, k)

elif startswith("&#", i):

match = charref.match(rawdata, i)

if match:

name = match.group()[2:-1]

self.handle_charref(name)

k = match.end()

if not startswith(';', k-1):

k = k - 1

i = self.updatepos(i, k)

continue

else:

if ";" in rawdata[i:]: # bail by consuming '&#'

self.handle_data(rawdata[i:i+2])

i = self.updatepos(i, i+2)

break

elif startswith('&', i):

match = entityref.match(rawdata, i)

if match:

name = match.group(1)

self.handle_entityref(name)

k = match.end()

if not startswith(';', k-1):

k = k - 1

i = self.updatepos(i, k)

continue

match = incomplete.match(rawdata, i)

if match:

# match.group() will contain at least 2 chars

if end and match.group() == rawdata[i:]:

self.error("EOF in middle of entity or char ref")

# incomplete

break

elif (i + 1) < n:

# not the end of the buffer, and can't be confused

# with some other construct

self.handle_data("&")

i = self.updatepos(i, i + 1)

else:

break

else:

assert 0, "interesting.search() lied"

# end while

if end and i < n and not self.cdata_elem:

self.handle_data(rawdata[i:n])

i = self.updatepos(i, n)

self.rawdata = rawdata[i:]

# Internal -- parse html declarations, return length or -1 if not terminated

# See w3.org/TR/html5/tokenization.html#markup-declaration-open-state

# See also parse_declaration in _markupbase

def parse_html_declaration(self, i):

rawdata = self.rawdata

if rawdata[i:i+2] != '<!':

self.error('unexpected call to parse_html_declaration()')

if rawdata[i:i+4] == '<!--':

# this case is actually already handled in goahead()

return self.parse_comment(i)

elif rawdata[i:i+3] == '<![':

return self.parse_marked_section(i)

elif rawdata[i:i+9].lower() == '<!doctype':

# find the closing >

gtpos = rawdata.find('>', i+9)

if gtpos == -1:

return -1

self.handle_decl(rawdata[i+2:gtpos])

return gtpos+1

else:

return self.parse_bogus_comment(i)

# Internal -- parse bogus comment, return length or -1 if not terminated

# see http://www.w3.org/TR/html5/tokenization.html#bogus-comment-state

def parse_bogus_comment(self, i, report=1):

rawdata = self.rawdata

if rawdata[i:i+2] not in ('<!', '</'):

self.error('unexpected call to parse_comment()')

pos = rawdata.find('>', i+2)

if pos == -1:

return -1

if report:

self.handle_comment(rawdata[i+2:pos])

return pos + 1

# Internal -- parse processing instr, return end or -1 if not terminated

def parse_pi(self, i):

rawdata = self.rawdata

assert rawdata[i:i+2] == '<?', 'unexpected call to parse_pi()'

match = piclose.search(rawdata, i+2) # >

if not match:

return -1

j = match.start()

self.handle_pi(rawdata[i+2: j])

j = match.end()

return j

# Internal -- handle starttag, return end or -1 if not terminated

def parse_starttag(self, i):

self.__starttag_text = None

endpos = self.check_for_whole_start_tag(i)

if endpos < 0:

return endpos

rawdata = self.rawdata

self.__starttag_text = rawdata[i:endpos]

# Now parse the data between i+1 and j into a tag and attrs

attrs = []

match = tagfind.match(rawdata, i+1)

assert match, 'unexpected call to parse_starttag()'

k = match.end()

self.lasttag = tag = match.group(1).lower()

while k < endpos:

m = attrfind.match(rawdata, k)

if not m:

break

attrname, rest, attrvalue = m.group(1, 2, 3)

if not rest:

attrvalue = None

elif attrvalue[:1] == '\'' == attrvalue[-1:] or \

attrvalue[:1] == '"' == attrvalue[-1:]:

attrvalue = attrvalue[1:-1]

if attrvalue:

attrvalue = self.unescape(attrvalue)

attrs.append((attrname.lower(), attrvalue))

k = m.end()

end = rawdata[k:endpos].strip()

if end not in (">", "/>"):

lineno, offset = self.getpos()

if "\n" in self.__starttag_text:

lineno = lineno + self.__starttag_text.count("\n")

offset = len(self.__starttag_text) \

- self.__starttag_text.rfind("\n")

else:

offset = offset + len(self.__starttag_text)

self.handle_data(rawdata[i:endpos])

return endpos

if end.endswith('/>'):

# XHTML-style empty tag: <span attr="value" />

self.handle_startendtag(tag, attrs)

else:

self.handle_starttag(tag, attrs)

if tag in self.CDATA_CONTENT_ELEMENTS:

self.set_cdata_mode(tag)

return endpos

# Internal -- check to see if we have a complete starttag; return end

# or -1 if incomplete.

def check_for_whole_start_tag(self, i):

rawdata = self.rawdata

m = locatestarttagend.match(rawdata, i)

if m:

j = m.end()

next = rawdata[j:j+1]

if next == ">":

return j + 1

if next == "/":

if rawdata.startswith("/>", j):

return j + 2

if rawdata.startswith("/", j):

# buffer boundary

return -1

# else bogus input

self.updatepos(i, j + 1)

self.error("malformed empty start tag")

if next == "":

# end of input

return -1

if next in ("abcdefghijklmnopqrstuvwxyz=/"

"ABCDEFGHIJKLMNOPQRSTUVWXYZ"):

# end of input in or before attribute value, or we have the

# '/' from a '/>' ending

return -1

if j > i:

return j

else:

return i + 1

raise AssertionError("we should not get here!")

# Internal -- parse endtag, return end or -1 if incomplete

def parse_endtag(self, i):

rawdata = self.rawdata

assert rawdata[i:i+2] == "</", "unexpected call to parse_endtag"

match = endendtag.search(rawdata, i+1) # >

if not match:

return -1

gtpos = match.end()

match = endtagfind.match(rawdata, i) # </ + tag + >

if not match:

if self.cdata_elem is not None:

self.handle_data(rawdata[i:gtpos])

return gtpos

# find the name: w3.org/TR/html5/tokenization.html#tag-name-state

namematch = tagfind.match(rawdata, i+2)

if not namematch:

# w3.org/TR/html5/tokenization.html#end-tag-open-state

if rawdata[i:i+3] == '</>':

return i+3

else:

return self.parse_bogus_comment(i)

tagname = namematch.group(1).lower()

# consume and ignore other stuff between the name and the >

# Note: this is not 100% correct, since we might have things like

# </tag attr=">">, but looking for > after tha name should cover

# most of the cases and is much simpler

gtpos = rawdata.find('>', namematch.end())

self.handle_endtag(tagname)

return gtpos+1

elem = match.group(1).lower() # script or style

if self.cdata_elem is not None:

if elem != self.cdata_elem:

self.handle_data(rawdata[i:gtpos])

return gtpos

self.handle_endtag(elem)

self.clear_cdata_mode()

return gtpos

# Overridable -- finish processing of start+end tag: <tag.../>

def handle_startendtag(self, tag, attrs):

self.handle_starttag(tag, attrs)

self.handle_endtag(tag)

# Overridable -- handle start tag

def handle_starttag(self, tag, attrs):

pass

# Overridable -- handle end tag

def handle_endtag(self, tag):

pass

# Overridable -- handle character reference

def handle_charref(self, name):

pass

# Overridable -- handle entity reference

def handle_entityref(self, name):

pass

# Overridable -- handle data

def handle_data(self, data):

pass

# Overridable -- handle comment

def handle_comment(self, data):

pass

# Overridable -- handle declaration

def handle_decl(self, decl):

pass

# Overridable -- handle processing instruction

def handle_pi(self, data):

pass

def unknown_decl(self, data):

pass

# Internal -- helper to remove special character quoting

entitydefs = None

def unescape(self, s):

if '&' not in s:

return s

def replaceEntities(s):

s = s.groups()[0]

try:

if s[0] == "#":

s = s[1:]

if s[0] in ['x','X']:

c = int(s[1:], 16)

else:

c = int(s)

return unichr(c)

except ValueError:

return '&#'+s+';'

else:

# Cannot use name2codepoint directly, because HTMLParser supports apos,

# which is not part of HTML 4

if HTMLParser.entitydefs is None:

import htmlentitydefs

entitydefs = {'apos':u"'"}

for k, v in htmlentitydefs.name2codepoint.iteritems():

entitydefs[k] = unichr(v)

HTMLParser.entitydefs = entitydefs

try:

return self.entitydefs[s]

except KeyError:

return '&'+s+';'

return re.sub(r"&(#?[xX]?(?:[0-9a-fA-F]+|\w{1,8}));", replaceEntities, s)

cpython/Lib/HTMLParser.py at 2.7 · python-emscripten/cpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

HTMLParser.py

Latest commit

History

Breadcrumbs

HTMLParser.py

File metadata and controls