/usr/share/pyshared/paste/util/template.py is in python-paste 1.7.5.1-4.1.
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 | """
A small templating language
This implements a small templating language for use internally in
Paste and Paste Script. This language implements if/elif/else,
for/continue/break, expressions, and blocks of Python code. The
syntax is::
{{any expression (function calls etc)}}
{{any expression | filter}}
{{for x in y}}...{{endfor}}
{{if x}}x{{elif y}}y{{else}}z{{endif}}
{{py:x=1}}
{{py:
def foo(bar):
return 'baz'
}}
{{default var = default_value}}
{{# comment}}
You use this with the ``Template`` class or the ``sub`` shortcut.
The ``Template`` class takes the template string and the name of
the template (for errors) and a default namespace. Then (like
``string.Template``) you can call the ``tmpl.substitute(**kw)``
method to make a substitution (or ``tmpl.substitute(a_dict)``).
``sub(content, **kw)`` substitutes the template immediately. You
can use ``__name='tmpl.html'`` to set the name of the template.
If there are syntax errors ``TemplateError`` will be raised.
"""
import re
import sys
import cgi
import urllib
from paste.util.looper import looper
__all__ = ['TemplateError', 'Template', 'sub', 'HTMLTemplate',
'sub_html', 'html', 'bunch']
token_re = re.compile(r'\{\{|\}\}')
in_re = re.compile(r'\s+in\s+')
var_re = re.compile(r'^[a-z_][a-z0-9_]*$', re.I)
class TemplateError(Exception):
"""Exception raised while parsing a template
"""
def __init__(self, message, position, name=None):
self.message = message
self.position = position
self.name = name
def __str__(self):
msg = '%s at line %s column %s' % (
self.message, self.position[0], self.position[1])
if self.name:
msg += ' in %s' % self.name
return msg
class _TemplateContinue(Exception):
pass
class _TemplateBreak(Exception):
pass
class Template(object):
default_namespace = {
'start_braces': '{{',
'end_braces': '}}',
'looper': looper,
}
default_encoding = 'utf8'
def __init__(self, content, name=None, namespace=None):
self.content = content
self._unicode = isinstance(content, unicode)
self.name = name
self._parsed = parse(content, name=name)
if namespace is None:
namespace = {}
self.namespace = namespace
def from_filename(cls, filename, namespace=None, encoding=None):
f = open(filename, 'rb')
c = f.read()
f.close()
if encoding:
c = c.decode(encoding)
return cls(content=c, name=filename, namespace=namespace)
from_filename = classmethod(from_filename)
def __repr__(self):
return '<%s %s name=%r>' % (
self.__class__.__name__,
hex(id(self))[2:], self.name)
def substitute(self, *args, **kw):
if args:
if kw:
raise TypeError(
"You can only give positional *or* keyword arguments")
if len(args) > 1:
raise TypeError(
"You can only give on positional argument")
kw = args[0]
ns = self.default_namespace.copy()
ns.update(self.namespace)
ns.update(kw)
result = self._interpret(ns)
return result
def _interpret(self, ns):
__traceback_hide__ = True
parts = []
self._interpret_codes(self._parsed, ns, out=parts)
return ''.join(parts)
def _interpret_codes(self, codes, ns, out):
__traceback_hide__ = True
for item in codes:
if isinstance(item, basestring):
out.append(item)
else:
self._interpret_code(item, ns, out)
def _interpret_code(self, code, ns, out):
__traceback_hide__ = True
name, pos = code[0], code[1]
if name == 'py':
self._exec(code[2], ns, pos)
elif name == 'continue':
raise _TemplateContinue()
elif name == 'break':
raise _TemplateBreak()
elif name == 'for':
vars, expr, content = code[2], code[3], code[4]
expr = self._eval(expr, ns, pos)
self._interpret_for(vars, expr, content, ns, out)
elif name == 'cond':
parts = code[2:]
self._interpret_if(parts, ns, out)
elif name == 'expr':
parts = code[2].split('|')
base = self._eval(parts[0], ns, pos)
for part in parts[1:]:
func = self._eval(part, ns, pos)
base = func(base)
out.append(self._repr(base, pos))
elif name == 'default':
var, expr = code[2], code[3]
if var not in ns:
result = self._eval(expr, ns, pos)
ns[var] = result
elif name == 'comment':
return
else:
assert 0, "Unknown code: %r" % name
def _interpret_for(self, vars, expr, content, ns, out):
__traceback_hide__ = True
for item in expr:
if len(vars) == 1:
ns[vars[0]] = item
else:
if len(vars) != len(item):
raise ValueError(
'Need %i items to unpack (got %i items)'
% (len(vars), len(item)))
for name, value in zip(vars, item):
ns[name] = value
try:
self._interpret_codes(content, ns, out)
except _TemplateContinue:
continue
except _TemplateBreak:
break
def _interpret_if(self, parts, ns, out):
__traceback_hide__ = True
# @@: if/else/else gets through
for part in parts:
assert not isinstance(part, basestring)
name, pos = part[0], part[1]
if name == 'else':
result = True
else:
result = self._eval(part[2], ns, pos)
if result:
self._interpret_codes(part[3], ns, out)
break
def _eval(self, code, ns, pos):
__traceback_hide__ = True
try:
value = eval(code, ns)
return value
except:
exc_info = sys.exc_info()
e = exc_info[1]
if getattr(e, 'args'):
arg0 = e.args[0]
else:
arg0 = str(e)
e.args = (self._add_line_info(arg0, pos),)
raise exc_info[0], e, exc_info[2]
def _exec(self, code, ns, pos):
__traceback_hide__ = True
try:
exec code in ns
except:
exc_info = sys.exc_info()
e = exc_info[1]
e.args = (self._add_line_info(e.args[0], pos),)
raise exc_info[0], e, exc_info[2]
def _repr(self, value, pos):
__traceback_hide__ = True
try:
if value is None:
return ''
if self._unicode:
try:
value = unicode(value)
except UnicodeDecodeError:
value = str(value)
else:
value = str(value)
except:
exc_info = sys.exc_info()
e = exc_info[1]
e.args = (self._add_line_info(e.args[0], pos),)
raise exc_info[0], e, exc_info[2]
else:
if self._unicode and isinstance(value, str):
if not self.decode_encoding:
raise UnicodeDecodeError(
'Cannot decode str value %r into unicode '
'(no default_encoding provided)' % value)
value = value.decode(self.default_encoding)
elif not self._unicode and isinstance(value, unicode):
if not self.decode_encoding:
raise UnicodeEncodeError(
'Cannot encode unicode value %r into str '
'(no default_encoding provided)' % value)
value = value.encode(self.default_encoding)
return value
def _add_line_info(self, msg, pos):
msg = "%s at line %s column %s" % (
msg, pos[0], pos[1])
if self.name:
msg += " in file %s" % self.name
return msg
def sub(content, **kw):
name = kw.get('__name')
tmpl = Template(content, name=name)
return tmpl.substitute(kw)
return result
def paste_script_template_renderer(content, vars, filename=None):
tmpl = Template(content, name=filename)
return tmpl.substitute(vars)
class bunch(dict):
def __init__(self, **kw):
for name, value in kw.items():
setattr(self, name, value)
def __setattr__(self, name, value):
self[name] = value
def __getattr__(self, name):
try:
return self[name]
except KeyError:
raise AttributeError(name)
def __getitem__(self, key):
if 'default' in self:
try:
return dict.__getitem__(self, key)
except KeyError:
return dict.__getitem__(self, 'default')
else:
return dict.__getitem__(self, key)
def __repr__(self):
items = [
(k, v) for k, v in self.items()]
items.sort()
return '<%s %s>' % (
self.__class__.__name__,
' '.join(['%s=%r' % (k, v) for k, v in items]))
############################################################
## HTML Templating
############################################################
class html(object):
def __init__(self, value):
self.value = value
def __str__(self):
return self.value
def __repr__(self):
return '<%s %r>' % (
self.__class__.__name__, self.value)
def html_quote(value):
if value is None:
return ''
if not isinstance(value, basestring):
if hasattr(value, '__unicode__'):
value = unicode(value)
else:
value = str(value)
value = cgi.escape(value, 1)
if isinstance(value, unicode):
value = value.encode('ascii', 'xmlcharrefreplace')
return value
def url(v):
if not isinstance(v, basestring):
if hasattr(v, '__unicode__'):
v = unicode(v)
else:
v = str(v)
if isinstance(v, unicode):
v = v.encode('utf8')
return urllib.quote(v)
def attr(**kw):
kw = kw.items()
kw.sort()
parts = []
for name, value in kw:
if value is None:
continue
if name.endswith('_'):
name = name[:-1]
parts.append('%s="%s"' % (html_quote(name), html_quote(value)))
return html(' '.join(parts))
class HTMLTemplate(Template):
default_namespace = Template.default_namespace.copy()
default_namespace.update(dict(
html=html,
attr=attr,
url=url,
))
def _repr(self, value, pos):
plain = Template._repr(self, value, pos)
if isinstance(value, html):
return plain
else:
return html_quote(plain)
def sub_html(content, **kw):
name = kw.get('__name')
tmpl = HTMLTemplate(content, name=name)
return tmpl.substitute(kw)
return result
############################################################
## Lexing and Parsing
############################################################
def lex(s, name=None, trim_whitespace=True):
"""
Lex a string into chunks:
>>> lex('hey')
['hey']
>>> lex('hey {{you}}')
['hey ', ('you', (1, 7))]
>>> lex('hey {{')
Traceback (most recent call last):
...
TemplateError: No }} to finish last expression at line 1 column 7
>>> lex('hey }}')
Traceback (most recent call last):
...
TemplateError: }} outside expression at line 1 column 7
>>> lex('hey {{ {{')
Traceback (most recent call last):
...
TemplateError: {{ inside expression at line 1 column 10
"""
in_expr = False
chunks = []
last = 0
last_pos = (1, 1)
for match in token_re.finditer(s):
expr = match.group(0)
pos = find_position(s, match.end())
if expr == '{{' and in_expr:
raise TemplateError('{{ inside expression', position=pos,
name=name)
elif expr == '}}' and not in_expr:
raise TemplateError('}} outside expression', position=pos,
name=name)
if expr == '{{':
part = s[last:match.start()]
if part:
chunks.append(part)
in_expr = True
else:
chunks.append((s[last:match.start()], last_pos))
in_expr = False
last = match.end()
last_pos = pos
if in_expr:
raise TemplateError('No }} to finish last expression',
name=name, position=last_pos)
part = s[last:]
if part:
chunks.append(part)
if trim_whitespace:
chunks = trim_lex(chunks)
return chunks
statement_re = re.compile(r'^(?:if |elif |else |for |py:)')
single_statements = ['endif', 'endfor', 'continue', 'break']
trail_whitespace_re = re.compile(r'\n[\t ]*$')
lead_whitespace_re = re.compile(r'^[\t ]*\n')
def trim_lex(tokens):
r"""
Takes a lexed set of tokens, and removes whitespace when there is
a directive on a line by itself:
>>> tokens = lex('{{if x}}\nx\n{{endif}}\ny', trim_whitespace=False)
>>> tokens
[('if x', (1, 3)), '\nx\n', ('endif', (3, 3)), '\ny']
>>> trim_lex(tokens)
[('if x', (1, 3)), 'x\n', ('endif', (3, 3)), 'y']
"""
for i in range(len(tokens)):
current = tokens[i]
if isinstance(tokens[i], basestring):
# we don't trim this
continue
item = current[0]
if not statement_re.search(item) and item not in single_statements:
continue
if not i:
prev = ''
else:
prev = tokens[i-1]
if i+1 >= len(tokens):
next = ''
else:
next = tokens[i+1]
if (not isinstance(next, basestring)
or not isinstance(prev, basestring)):
continue
if ((not prev or trail_whitespace_re.search(prev))
and (not next or lead_whitespace_re.search(next))):
if prev:
m = trail_whitespace_re.search(prev)
# +1 to leave the leading \n on:
prev = prev[:m.start()+1]
tokens[i-1] = prev
if next:
m = lead_whitespace_re.search(next)
next = next[m.end():]
tokens[i+1] = next
return tokens
def find_position(string, index):
"""Given a string and index, return (line, column)"""
leading = string[:index].splitlines()
return (len(leading), len(leading[-1])+1)
def parse(s, name=None):
r"""
Parses a string into a kind of AST
>>> parse('{{x}}')
[('expr', (1, 3), 'x')]
>>> parse('foo')
['foo']
>>> parse('{{if x}}test{{endif}}')
[('cond', (1, 3), ('if', (1, 3), 'x', ['test']))]
>>> parse('series->{{for x in y}}x={{x}}{{endfor}}')
['series->', ('for', (1, 11), ('x',), 'y', ['x=', ('expr', (1, 27), 'x')])]
>>> parse('{{for x, y in z:}}{{continue}}{{endfor}}')
[('for', (1, 3), ('x', 'y'), 'z', [('continue', (1, 21))])]
>>> parse('{{py:x=1}}')
[('py', (1, 3), 'x=1')]
>>> parse('{{if x}}a{{elif y}}b{{else}}c{{endif}}')
[('cond', (1, 3), ('if', (1, 3), 'x', ['a']), ('elif', (1, 12), 'y', ['b']), ('else', (1, 23), None, ['c']))]
Some exceptions::
>>> parse('{{continue}}')
Traceback (most recent call last):
...
TemplateError: continue outside of for loop at line 1 column 3
>>> parse('{{if x}}foo')
Traceback (most recent call last):
...
TemplateError: No {{endif}} at line 1 column 3
>>> parse('{{else}}')
Traceback (most recent call last):
...
TemplateError: else outside of an if block at line 1 column 3
>>> parse('{{if x}}{{for x in y}}{{endif}}{{endfor}}')
Traceback (most recent call last):
...
TemplateError: Unexpected endif at line 1 column 25
>>> parse('{{if}}{{endif}}')
Traceback (most recent call last):
...
TemplateError: if with no expression at line 1 column 3
>>> parse('{{for x y}}{{endfor}}')
Traceback (most recent call last):
...
TemplateError: Bad for (no "in") in 'x y' at line 1 column 3
>>> parse('{{py:x=1\ny=2}}')
Traceback (most recent call last):
...
TemplateError: Multi-line py blocks must start with a newline at line 1 column 3
"""
tokens = lex(s, name=name)
result = []
while tokens:
next, tokens = parse_expr(tokens, name)
result.append(next)
return result
def parse_expr(tokens, name, context=()):
if isinstance(tokens[0], basestring):
return tokens[0], tokens[1:]
expr, pos = tokens[0]
expr = expr.strip()
if expr.startswith('py:'):
expr = expr[3:].lstrip(' \t')
if expr.startswith('\n'):
expr = expr[1:]
else:
if '\n' in expr:
raise TemplateError(
'Multi-line py blocks must start with a newline',
position=pos, name=name)
return ('py', pos, expr), tokens[1:]
elif expr in ('continue', 'break'):
if 'for' not in context:
raise TemplateError(
'continue outside of for loop',
position=pos, name=name)
return (expr, pos), tokens[1:]
elif expr.startswith('if '):
return parse_cond(tokens, name, context)
elif (expr.startswith('elif ')
or expr == 'else'):
raise TemplateError(
'%s outside of an if block' % expr.split()[0],
position=pos, name=name)
elif expr in ('if', 'elif', 'for'):
raise TemplateError(
'%s with no expression' % expr,
position=pos, name=name)
elif expr in ('endif', 'endfor'):
raise TemplateError(
'Unexpected %s' % expr,
position=pos, name=name)
elif expr.startswith('for '):
return parse_for(tokens, name, context)
elif expr.startswith('default '):
return parse_default(tokens, name, context)
elif expr.startswith('#'):
return ('comment', pos, tokens[0][0]), tokens[1:]
return ('expr', pos, tokens[0][0]), tokens[1:]
def parse_cond(tokens, name, context):
start = tokens[0][1]
pieces = []
context = context + ('if',)
while 1:
if not tokens:
raise TemplateError(
'Missing {{endif}}',
position=start, name=name)
if (isinstance(tokens[0], tuple)
and tokens[0][0] == 'endif'):
return ('cond', start) + tuple(pieces), tokens[1:]
next, tokens = parse_one_cond(tokens, name, context)
pieces.append(next)
def parse_one_cond(tokens, name, context):
(first, pos), tokens = tokens[0], tokens[1:]
content = []
if first.endswith(':'):
first = first[:-1]
if first.startswith('if '):
part = ('if', pos, first[3:].lstrip(), content)
elif first.startswith('elif '):
part = ('elif', pos, first[5:].lstrip(), content)
elif first == 'else':
part = ('else', pos, None, content)
else:
assert 0, "Unexpected token %r at %s" % (first, pos)
while 1:
if not tokens:
raise TemplateError(
'No {{endif}}',
position=pos, name=name)
if (isinstance(tokens[0], tuple)
and (tokens[0][0] == 'endif'
or tokens[0][0].startswith('elif ')
or tokens[0][0] == 'else')):
return part, tokens
next, tokens = parse_expr(tokens, name, context)
content.append(next)
def parse_for(tokens, name, context):
first, pos = tokens[0]
tokens = tokens[1:]
context = ('for',) + context
content = []
assert first.startswith('for ')
if first.endswith(':'):
first = first[:-1]
first = first[3:].strip()
match = in_re.search(first)
if not match:
raise TemplateError(
'Bad for (no "in") in %r' % first,
position=pos, name=name)
vars = first[:match.start()]
if '(' in vars:
raise TemplateError(
'You cannot have () in the variable section of a for loop (%r)'
% vars, position=pos, name=name)
vars = tuple([
v.strip() for v in first[:match.start()].split(',')
if v.strip()])
expr = first[match.end():]
while 1:
if not tokens:
raise TemplateError(
'No {{endfor}}',
position=pos, name=name)
if (isinstance(tokens[0], tuple)
and tokens[0][0] == 'endfor'):
return ('for', pos, vars, expr, content), tokens[1:]
next, tokens = parse_expr(tokens, name, context)
content.append(next)
def parse_default(tokens, name, context):
first, pos = tokens[0]
assert first.startswith('default ')
first = first.split(None, 1)[1]
parts = first.split('=', 1)
if len(parts) == 1:
raise TemplateError(
"Expression must be {{default var=value}}; no = found in %r" % first,
position=pos, name=name)
var = parts[0].strip()
if ',' in var:
raise TemplateError(
"{{default x, y = ...}} is not supported",
position=pos, name=name)
if not var_re.search(var):
raise TemplateError(
"Not a valid variable name for {{default}}: %r"
% var, position=pos, name=name)
expr = parts[1].strip()
return ('default', pos, var, expr), tokens[1:]
_fill_command_usage = """\
%prog [OPTIONS] TEMPLATE arg=value
Use py:arg=value to set a Python value; otherwise all values are
strings.
"""
def fill_command(args=None):
import sys, optparse, pkg_resources, os
if args is None:
args = sys.argv[1:]
dist = pkg_resources.get_distribution('Paste')
parser = optparse.OptionParser(
version=str(dist),
usage=_fill_command_usage)
parser.add_option(
'-o', '--output',
dest='output',
metavar="FILENAME",
help="File to write output to (default stdout)")
parser.add_option(
'--html',
dest='use_html',
action='store_true',
help="Use HTML style filling (including automatic HTML quoting)")
parser.add_option(
'--env',
dest='use_env',
action='store_true',
help="Put the environment in as top-level variables")
options, args = parser.parse_args(args)
if len(args) < 1:
print 'You must give a template filename'
print dir(parser)
assert 0
template_name = args[0]
args = args[1:]
vars = {}
if options.use_env:
vars.update(os.environ)
for value in args:
if '=' not in value:
print 'Bad argument: %r' % value
sys.exit(2)
name, value = value.split('=', 1)
if name.startswith('py:'):
name = name[:3]
value = eval(value)
vars[name] = value
if template_name == '-':
template_content = sys.stdin.read()
template_name = '<stdin>'
else:
f = open(template_name, 'rb')
template_content = f.read()
f.close()
if options.use_html:
TemplateClass = HTMLTemplate
else:
TemplateClass = Template
template = TemplateClass(template_content, name=template_name)
result = template.substitute(vars)
if options.output:
f = open(options.output, 'wb')
f.write(result)
f.close()
else:
sys.stdout.write(result)
if __name__ == '__main__':
from paste.util.template import fill_command
fill_command()
|