codegen.py 38 KB

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  1. # codegen.py
  2. # Copyright (C) 2006, 2007, 2008, 2009, 2010 Michael Bayer mike_mp@zzzcomputing.com
  3. #
  4. # This module is part of Mako and is released under
  5. # the MIT License: http://www.opensource.org/licenses/mit-license.php
  6. """provides functionality for rendering a parsetree constructing into module source code."""
  7. import time
  8. import re
  9. from mako.pygen import PythonPrinter
  10. from mako import util, ast, parsetree, filters
  11. MAGIC_NUMBER = 5
  12. def compile(node,
  13. uri,
  14. filename=None,
  15. default_filters=None,
  16. buffer_filters=None,
  17. imports=None,
  18. source_encoding=None,
  19. generate_magic_comment=True,
  20. disable_unicode=False):
  21. """Generate module source code given a parsetree node,
  22. uri, and optional source filename"""
  23. # if on Py2K, push the "source_encoding" string to be
  24. # a bytestring itself, as we will be embedding it into
  25. # the generated source and we don't want to coerce the
  26. # result into a unicode object, in "disable_unicode" mode
  27. if not util.py3k and isinstance(source_encoding, unicode):
  28. source_encoding = source_encoding.encode(source_encoding)
  29. buf = util.FastEncodingBuffer()
  30. printer = PythonPrinter(buf)
  31. _GenerateRenderMethod(printer,
  32. _CompileContext(uri,
  33. filename,
  34. default_filters,
  35. buffer_filters,
  36. imports,
  37. source_encoding,
  38. generate_magic_comment,
  39. disable_unicode),
  40. node)
  41. return buf.getvalue()
  42. class _CompileContext(object):
  43. def __init__(self,
  44. uri,
  45. filename,
  46. default_filters,
  47. buffer_filters,
  48. imports,
  49. source_encoding,
  50. generate_magic_comment,
  51. disable_unicode):
  52. self.uri = uri
  53. self.filename = filename
  54. self.default_filters = default_filters
  55. self.buffer_filters = buffer_filters
  56. self.imports = imports
  57. self.source_encoding = source_encoding
  58. self.generate_magic_comment = generate_magic_comment
  59. self.disable_unicode = disable_unicode
  60. class _GenerateRenderMethod(object):
  61. """A template visitor object which generates the
  62. full module source for a template.
  63. """
  64. def __init__(self, printer, compiler, node):
  65. self.printer = printer
  66. self.last_source_line = -1
  67. self.compiler = compiler
  68. self.node = node
  69. self.identifier_stack = [None]
  70. self.in_def = isinstance(node, parsetree.DefTag)
  71. if self.in_def:
  72. name = "render_" + node.name
  73. args = node.function_decl.get_argument_expressions()
  74. filtered = len(node.filter_args.args) > 0
  75. buffered = eval(node.attributes.get('buffered', 'False'))
  76. cached = eval(node.attributes.get('cached', 'False'))
  77. defs = None
  78. pagetag = None
  79. else:
  80. defs = self.write_toplevel()
  81. pagetag = self.compiler.pagetag
  82. name = "render_body"
  83. if pagetag is not None:
  84. args = pagetag.body_decl.get_argument_expressions()
  85. if not pagetag.body_decl.kwargs:
  86. args += ['**pageargs']
  87. cached = eval(pagetag.attributes.get('cached', 'False'))
  88. else:
  89. args = ['**pageargs']
  90. cached = False
  91. buffered = filtered = False
  92. if args is None:
  93. args = ['context']
  94. else:
  95. args = [a for a in ['context'] + args]
  96. self.write_render_callable(
  97. pagetag or node,
  98. name, args,
  99. buffered, filtered, cached)
  100. if defs is not None:
  101. for node in defs:
  102. _GenerateRenderMethod(printer, compiler, node)
  103. @property
  104. def identifiers(self):
  105. return self.identifier_stack[-1]
  106. def write_toplevel(self):
  107. """Traverse a template structure for module-level directives and
  108. generate the start of module-level code.
  109. """
  110. inherit = []
  111. namespaces = {}
  112. module_code = []
  113. encoding =[None]
  114. self.compiler.pagetag = None
  115. class FindTopLevel(object):
  116. def visitInheritTag(s, node):
  117. inherit.append(node)
  118. def visitNamespaceTag(s, node):
  119. namespaces[node.name] = node
  120. def visitPageTag(s, node):
  121. self.compiler.pagetag = node
  122. def visitCode(s, node):
  123. if node.ismodule:
  124. module_code.append(node)
  125. f = FindTopLevel()
  126. for n in self.node.nodes:
  127. n.accept_visitor(f)
  128. self.compiler.namespaces = namespaces
  129. module_ident = set()
  130. for n in module_code:
  131. module_ident = module_ident.union(n.declared_identifiers())
  132. module_identifiers = _Identifiers()
  133. module_identifiers.declared = module_ident
  134. # module-level names, python code
  135. if self.compiler.generate_magic_comment and \
  136. self.compiler.source_encoding:
  137. self.printer.writeline("# -*- encoding:%s -*-" %
  138. self.compiler.source_encoding)
  139. self.printer.writeline("from mako import runtime, filters, cache")
  140. self.printer.writeline("UNDEFINED = runtime.UNDEFINED")
  141. self.printer.writeline("__M_dict_builtin = dict")
  142. self.printer.writeline("__M_locals_builtin = locals")
  143. self.printer.writeline("_magic_number = %r" % MAGIC_NUMBER)
  144. self.printer.writeline("_modified_time = %r" % time.time())
  145. self.printer.writeline(
  146. "_template_filename=%r" % self.compiler.filename)
  147. self.printer.writeline("_template_uri=%r" % self.compiler.uri)
  148. self.printer.writeline(
  149. "_template_cache=cache.Cache(__name__, _modified_time)")
  150. self.printer.writeline(
  151. "_source_encoding=%r" % self.compiler.source_encoding)
  152. if self.compiler.imports:
  153. buf = ''
  154. for imp in self.compiler.imports:
  155. buf += imp + "\n"
  156. self.printer.writeline(imp)
  157. impcode = ast.PythonCode(
  158. buf,
  159. source='', lineno=0,
  160. pos=0,
  161. filename='template defined imports')
  162. else:
  163. impcode = None
  164. main_identifiers = module_identifiers.branch(self.node)
  165. module_identifiers.topleveldefs = \
  166. module_identifiers.topleveldefs.\
  167. union(main_identifiers.topleveldefs)
  168. module_identifiers.declared.add("UNDEFINED")
  169. if impcode:
  170. module_identifiers.declared.update(impcode.declared_identifiers)
  171. self.compiler.identifiers = module_identifiers
  172. self.printer.writeline("_exports = %r" %
  173. [n.name for n in
  174. main_identifiers.topleveldefs.values()]
  175. )
  176. self.printer.write("\n\n")
  177. if len(module_code):
  178. self.write_module_code(module_code)
  179. if len(inherit):
  180. self.write_namespaces(namespaces)
  181. self.write_inherit(inherit[-1])
  182. elif len(namespaces):
  183. self.write_namespaces(namespaces)
  184. return main_identifiers.topleveldefs.values()
  185. def write_render_callable(self, node, name, args, buffered, filtered, cached):
  186. """write a top-level render callable.
  187. this could be the main render() method or that of a top-level def."""
  188. if self.in_def:
  189. decorator = node.decorator
  190. if decorator:
  191. self.printer.writeline("@runtime._decorate_toplevel(%s)" % decorator)
  192. self.printer.writelines(
  193. "def %s(%s):" % (name, ','.join(args)),
  194. "context.caller_stack._push_frame()",
  195. "try:"
  196. )
  197. if buffered or filtered or cached:
  198. self.printer.writeline("context._push_buffer()")
  199. self.identifier_stack.append(self.compiler.identifiers.branch(self.node))
  200. if not self.in_def and '**pageargs' in args:
  201. self.identifier_stack[-1].argument_declared.add('pageargs')
  202. if not self.in_def and (
  203. len(self.identifiers.locally_assigned) > 0 or
  204. len(self.identifiers.argument_declared) > 0
  205. ):
  206. self.printer.writeline("__M_locals = __M_dict_builtin(%s)" %
  207. ','.join([
  208. "%s=%s" % (x, x) for x in
  209. self.identifiers.argument_declared
  210. ]))
  211. self.write_variable_declares(self.identifiers, toplevel=True)
  212. for n in self.node.nodes:
  213. n.accept_visitor(self)
  214. self.write_def_finish(self.node, buffered, filtered, cached)
  215. self.printer.writeline(None)
  216. self.printer.write("\n\n")
  217. if cached:
  218. self.write_cache_decorator(
  219. node, name,
  220. args, buffered,
  221. self.identifiers, toplevel=True)
  222. def write_module_code(self, module_code):
  223. """write module-level template code, i.e. that which
  224. is enclosed in <%! %> tags in the template."""
  225. for n in module_code:
  226. self.write_source_comment(n)
  227. self.printer.write_indented_block(n.text)
  228. def write_inherit(self, node):
  229. """write the module-level inheritance-determination callable."""
  230. self.printer.writelines(
  231. "def _mako_inherit(template, context):",
  232. "_mako_generate_namespaces(context)",
  233. "return runtime._inherit_from(context, %s, _template_uri)" %
  234. (node.parsed_attributes['file']),
  235. None
  236. )
  237. def write_namespaces(self, namespaces):
  238. """write the module-level namespace-generating callable."""
  239. self.printer.writelines(
  240. "def _mako_get_namespace(context, name):",
  241. "try:",
  242. "return context.namespaces[(__name__, name)]",
  243. "except KeyError:",
  244. "_mako_generate_namespaces(context)",
  245. "return context.namespaces[(__name__, name)]",
  246. None,None
  247. )
  248. self.printer.writeline("def _mako_generate_namespaces(context):")
  249. for node in namespaces.values():
  250. if node.attributes.has_key('import'):
  251. self.compiler.has_ns_imports = True
  252. self.write_source_comment(node)
  253. if len(node.nodes):
  254. self.printer.writeline("def make_namespace():")
  255. export = []
  256. identifiers = self.compiler.identifiers.branch(node)
  257. self.in_def = True
  258. class NSDefVisitor(object):
  259. def visitDefTag(s, node):
  260. self.write_inline_def(node, identifiers, nested=False)
  261. export.append(node.name)
  262. vis = NSDefVisitor()
  263. for n in node.nodes:
  264. n.accept_visitor(vis)
  265. self.printer.writeline("return [%s]" % (','.join(export)))
  266. self.printer.writeline(None)
  267. self.in_def = False
  268. callable_name = "make_namespace()"
  269. else:
  270. callable_name = "None"
  271. self.printer.writeline(
  272. "ns = runtime.Namespace(%r, context._clean_inheritance_tokens(),"
  273. " templateuri=%s, callables=%s, calling_uri=_template_uri, module=%s)" %
  274. (
  275. node.name,
  276. node.parsed_attributes.get('file', 'None'),
  277. callable_name,
  278. node.parsed_attributes.get('module', 'None'))
  279. )
  280. if eval(node.attributes.get('inheritable', "False")):
  281. self.printer.writeline("context['self'].%s = ns" % (node.name))
  282. self.printer.writeline("context.namespaces[(__name__, %s)] = ns" % repr(node.name))
  283. self.printer.write("\n")
  284. if not len(namespaces):
  285. self.printer.writeline("pass")
  286. self.printer.writeline(None)
  287. def write_variable_declares(self, identifiers, toplevel=False, limit=None):
  288. """write variable declarations at the top of a function.
  289. the variable declarations are in the form of callable
  290. definitions for defs and/or name lookup within the
  291. function's context argument. the names declared are based
  292. on the names that are referenced in the function body,
  293. which don't otherwise have any explicit assignment
  294. operation. names that are assigned within the body are
  295. assumed to be locally-scoped variables and are not
  296. separately declared.
  297. for def callable definitions, if the def is a top-level
  298. callable then a 'stub' callable is generated which wraps
  299. the current Context into a closure. if the def is not
  300. top-level, it is fully rendered as a local closure.
  301. """
  302. # collection of all defs available to us in this scope
  303. comp_idents = dict([(c.name, c) for c in identifiers.defs])
  304. to_write = set()
  305. # write "context.get()" for all variables we are going to
  306. # need that arent in the namespace yet
  307. to_write = to_write.union(identifiers.undeclared)
  308. # write closure functions for closures that we define
  309. # right here
  310. to_write = to_write.union([c.name for c in identifiers.closuredefs.values()])
  311. # remove identifiers that are declared in the argument
  312. # signature of the callable
  313. to_write = to_write.difference(identifiers.argument_declared)
  314. # remove identifiers that we are going to assign to.
  315. # in this way we mimic Python's behavior,
  316. # i.e. assignment to a variable within a block
  317. # means that variable is now a "locally declared" var,
  318. # which cannot be referenced beforehand.
  319. to_write = to_write.difference(identifiers.locally_declared)
  320. # if a limiting set was sent, constraint to those items in that list
  321. # (this is used for the caching decorator)
  322. if limit is not None:
  323. to_write = to_write.intersection(limit)
  324. if toplevel and getattr(self.compiler, 'has_ns_imports', False):
  325. self.printer.writeline("_import_ns = {}")
  326. self.compiler.has_imports = True
  327. for ident, ns in self.compiler.namespaces.iteritems():
  328. if ns.attributes.has_key('import'):
  329. self.printer.writeline(
  330. "_mako_get_namespace(context, %r)._populate(_import_ns, %r)" %
  331. (
  332. ident,
  333. re.split(r'\s*,\s*', ns.attributes['import'])
  334. ))
  335. for ident in to_write:
  336. if ident in comp_idents:
  337. comp = comp_idents[ident]
  338. if comp.is_root():
  339. self.write_def_decl(comp, identifiers)
  340. else:
  341. self.write_inline_def(comp, identifiers, nested=True)
  342. elif ident in self.compiler.namespaces:
  343. self.printer.writeline(
  344. "%s = _mako_get_namespace(context, %r)" %
  345. (ident, ident)
  346. )
  347. else:
  348. if getattr(self.compiler, 'has_ns_imports', False):
  349. self.printer.writeline(
  350. "%s = _import_ns.get(%r, context.get(%r, UNDEFINED))" %
  351. (ident, ident, ident))
  352. else:
  353. self.printer.writeline("%s = context.get(%r, UNDEFINED)" % (ident, ident))
  354. self.printer.writeline("__M_writer = context.writer()")
  355. def write_source_comment(self, node):
  356. """write a source comment containing the line number of the corresponding template line."""
  357. if self.last_source_line != node.lineno:
  358. self.printer.writeline("# SOURCE LINE %d" % node.lineno)
  359. self.last_source_line = node.lineno
  360. def write_def_decl(self, node, identifiers):
  361. """write a locally-available callable referencing a top-level def"""
  362. funcname = node.function_decl.funcname
  363. namedecls = node.function_decl.get_argument_expressions()
  364. nameargs = node.function_decl.get_argument_expressions(include_defaults=False)
  365. if not self.in_def and (
  366. len(self.identifiers.locally_assigned) > 0 or
  367. len(self.identifiers.argument_declared) > 0):
  368. nameargs.insert(0, 'context.locals_(__M_locals)')
  369. else:
  370. nameargs.insert(0, 'context')
  371. self.printer.writeline("def %s(%s):" % (funcname, ",".join(namedecls)))
  372. self.printer.writeline("return render_%s(%s)" % (funcname, ",".join(nameargs)))
  373. self.printer.writeline(None)
  374. def write_inline_def(self, node, identifiers, nested):
  375. """write a locally-available def callable inside an enclosing def."""
  376. namedecls = node.function_decl.get_argument_expressions()
  377. decorator = node.decorator
  378. if decorator:
  379. self.printer.writeline("@runtime._decorate_inline(context, %s)" % decorator)
  380. self.printer.writeline("def %s(%s):" % (node.name, ",".join(namedecls)))
  381. filtered = len(node.filter_args.args) > 0
  382. buffered = eval(node.attributes.get('buffered', 'False'))
  383. cached = eval(node.attributes.get('cached', 'False'))
  384. self.printer.writelines(
  385. "context.caller_stack._push_frame()",
  386. "try:"
  387. )
  388. if buffered or filtered or cached:
  389. self.printer.writelines(
  390. "context._push_buffer()",
  391. )
  392. identifiers = identifiers.branch(node, nested=nested)
  393. self.write_variable_declares(identifiers)
  394. self.identifier_stack.append(identifiers)
  395. for n in node.nodes:
  396. n.accept_visitor(self)
  397. self.identifier_stack.pop()
  398. self.write_def_finish(node, buffered, filtered, cached)
  399. self.printer.writeline(None)
  400. if cached:
  401. self.write_cache_decorator(node, node.name,
  402. namedecls, False, identifiers,
  403. inline=True, toplevel=False)
  404. def write_def_finish(self, node, buffered, filtered, cached, callstack=True):
  405. """write the end section of a rendering function, either outermost or inline.
  406. this takes into account if the rendering function was filtered, buffered, etc.
  407. and closes the corresponding try: block if any, and writes code to retrieve
  408. captured content, apply filters, send proper return value."""
  409. if not buffered and not cached and not filtered:
  410. self.printer.writeline("return ''")
  411. if callstack:
  412. self.printer.writelines(
  413. "finally:",
  414. "context.caller_stack._pop_frame()",
  415. None
  416. )
  417. if buffered or filtered or cached:
  418. if buffered or cached:
  419. # in a caching scenario, don't try to get a writer
  420. # from the context after popping; assume the caching
  421. # implemenation might be using a context with no
  422. # extra buffers
  423. self.printer.writelines(
  424. "finally:",
  425. "__M_buf = context._pop_buffer()"
  426. )
  427. else:
  428. self.printer.writelines(
  429. "finally:",
  430. "__M_buf, __M_writer = context._pop_buffer_and_writer()"
  431. )
  432. if callstack:
  433. self.printer.writeline("context.caller_stack._pop_frame()")
  434. s = "__M_buf.getvalue()"
  435. if filtered:
  436. s = self.create_filter_callable(node.filter_args.args, s, False)
  437. self.printer.writeline(None)
  438. if buffered and not cached:
  439. s = self.create_filter_callable(self.compiler.buffer_filters, s, False)
  440. if buffered or cached:
  441. self.printer.writeline("return %s" % s)
  442. else:
  443. self.printer.writelines(
  444. "__M_writer(%s)" % s,
  445. "return ''"
  446. )
  447. def write_cache_decorator(self, node_or_pagetag, name,
  448. args, buffered, identifiers,
  449. inline=False, toplevel=False):
  450. """write a post-function decorator to replace a rendering
  451. callable with a cached version of itself."""
  452. self.printer.writeline("__M_%s = %s" % (name, name))
  453. cachekey = node_or_pagetag.parsed_attributes.get('cache_key', repr(name))
  454. cacheargs = {}
  455. for arg in (
  456. ('cache_type', 'type'), ('cache_dir', 'data_dir'),
  457. ('cache_timeout', 'expiretime'), ('cache_url', 'url')):
  458. val = node_or_pagetag.parsed_attributes.get(arg[0], None)
  459. if val is not None:
  460. if arg[1] == 'expiretime':
  461. cacheargs[arg[1]] = int(eval(val))
  462. else:
  463. cacheargs[arg[1]] = val
  464. else:
  465. if self.compiler.pagetag is not None:
  466. val = self.compiler.pagetag.parsed_attributes.get(arg[0], None)
  467. if val is not None:
  468. if arg[1] == 'expiretime':
  469. cacheargs[arg[1]] == int(eval(val))
  470. else:
  471. cacheargs[arg[1]] = val
  472. self.printer.writeline("def %s(%s):" % (name, ','.join(args)))
  473. # form "arg1, arg2, arg3=arg3, arg4=arg4", etc.
  474. pass_args = [
  475. '=' in a and "%s=%s" % ((a.split('=')[0],)*2) or a
  476. for a in args
  477. ]
  478. self.write_variable_declares(
  479. identifiers,
  480. toplevel=toplevel,
  481. limit=node_or_pagetag.undeclared_identifiers()
  482. )
  483. if buffered:
  484. s = "context.get('local')."\
  485. "get_cached(%s, defname=%r, %screatefunc=lambda:__M_%s(%s))" % \
  486. (cachekey, name,
  487. ''.join(["%s=%s, " % (k,v) for k, v in cacheargs.iteritems()]),
  488. name, ','.join(pass_args))
  489. # apply buffer_filters
  490. s = self.create_filter_callable(self.compiler.buffer_filters, s, False)
  491. self.printer.writelines("return " + s,None)
  492. else:
  493. self.printer.writelines(
  494. "__M_writer(context.get('local')."
  495. "get_cached(%s, defname=%r, %screatefunc=lambda:__M_%s(%s)))" %
  496. (cachekey, name,
  497. ''.join(["%s=%s, " % (k,v) for k, v in cacheargs.iteritems()]),
  498. name, ','.join(pass_args)),
  499. "return ''",
  500. None
  501. )
  502. def create_filter_callable(self, args, target, is_expression):
  503. """write a filter-applying expression based on the filters
  504. present in the given filter names, adjusting for the global
  505. 'default' filter aliases as needed."""
  506. def locate_encode(name):
  507. if re.match(r'decode\..+', name):
  508. return "filters." + name
  509. elif self.compiler.disable_unicode:
  510. return filters.NON_UNICODE_ESCAPES.get(name, name)
  511. else:
  512. return filters.DEFAULT_ESCAPES.get(name, name)
  513. if 'n' not in args:
  514. if is_expression:
  515. if self.compiler.pagetag:
  516. args = self.compiler.pagetag.filter_args.args + args
  517. if self.compiler.default_filters:
  518. args = self.compiler.default_filters + args
  519. for e in args:
  520. # if filter given as a function, get just the identifier portion
  521. if e == 'n':
  522. continue
  523. m = re.match(r'(.+?)(\(.*\))', e)
  524. if m:
  525. (ident, fargs) = m.group(1,2)
  526. f = locate_encode(ident)
  527. e = f + fargs
  528. else:
  529. x = e
  530. e = locate_encode(e)
  531. assert e is not None
  532. target = "%s(%s)" % (e, target)
  533. return target
  534. def visitExpression(self, node):
  535. self.write_source_comment(node)
  536. if len(node.escapes) or \
  537. (
  538. self.compiler.pagetag is not None and
  539. len(self.compiler.pagetag.filter_args.args)
  540. ) or \
  541. len(self.compiler.default_filters):
  542. s = self.create_filter_callable(node.escapes_code.args, "%s" % node.text, True)
  543. self.printer.writeline("__M_writer(%s)" % s)
  544. else:
  545. self.printer.writeline("__M_writer(%s)" % node.text)
  546. def visitControlLine(self, node):
  547. if node.isend:
  548. if not node.get_children():
  549. self.printer.writeline("pass")
  550. self.printer.writeline(None)
  551. else:
  552. self.write_source_comment(node)
  553. self.printer.writeline(node.text)
  554. def visitText(self, node):
  555. self.write_source_comment(node)
  556. self.printer.writeline("__M_writer(%s)" % repr(node.content))
  557. def visitTextTag(self, node):
  558. filtered = len(node.filter_args.args) > 0
  559. if filtered:
  560. self.printer.writelines(
  561. "__M_writer = context._push_writer()",
  562. "try:",
  563. )
  564. for n in node.nodes:
  565. n.accept_visitor(self)
  566. if filtered:
  567. self.printer.writelines(
  568. "finally:",
  569. "__M_buf, __M_writer = context._pop_buffer_and_writer()",
  570. "__M_writer(%s)" %
  571. self.create_filter_callable(
  572. node.filter_args.args,
  573. "__M_buf.getvalue()",
  574. False),
  575. None
  576. )
  577. def visitCode(self, node):
  578. if not node.ismodule:
  579. self.write_source_comment(node)
  580. self.printer.write_indented_block(node.text)
  581. if not self.in_def and len(self.identifiers.locally_assigned) > 0:
  582. # if we are the "template" def, fudge locally
  583. # declared/modified variables into the "__M_locals" dictionary,
  584. # which is used for def calls within the same template,
  585. # to simulate "enclosing scope"
  586. self.printer.writeline('__M_locals_builtin_stored = __M_locals_builtin()')
  587. self.printer.writeline(
  588. '__M_locals.update(__M_dict_builtin([(__M_key,'
  589. ' __M_locals_builtin_stored[__M_key]) for '
  590. '__M_key in [%s] if __M_key in __M_locals_builtin_stored]))' %
  591. ','.join([repr(x) for x in node.declared_identifiers()]))
  592. def visitIncludeTag(self, node):
  593. self.write_source_comment(node)
  594. args = node.attributes.get('args')
  595. if args:
  596. self.printer.writeline(
  597. "runtime._include_file(context, %s, _template_uri, %s)" %
  598. (node.parsed_attributes['file'], args))
  599. else:
  600. self.printer.writeline(
  601. "runtime._include_file(context, %s, _template_uri)" %
  602. (node.parsed_attributes['file']))
  603. def visitNamespaceTag(self, node):
  604. pass
  605. def visitDefTag(self, node):
  606. pass
  607. def visitCallNamespaceTag(self, node):
  608. # TODO: we can put namespace-specific checks here, such
  609. # as ensure the given namespace will be imported,
  610. # pre-import the namespace, etc.
  611. self.visitCallTag(node)
  612. def visitCallTag(self, node):
  613. self.printer.writeline("def ccall(caller):")
  614. export = ['body']
  615. callable_identifiers = self.identifiers.branch(node, nested=True)
  616. body_identifiers = callable_identifiers.branch(node, nested=False)
  617. # we want the 'caller' passed to ccall to be used
  618. # for the body() function, but for other non-body()
  619. # <%def>s within <%call> we want the current caller
  620. # off the call stack (if any)
  621. body_identifiers.add_declared('caller')
  622. self.identifier_stack.append(body_identifiers)
  623. class DefVisitor(object):
  624. def visitDefTag(s, node):
  625. self.write_inline_def(node, callable_identifiers, nested=False)
  626. export.append(node.name)
  627. # remove defs that are within the <%call> from the "closuredefs" defined
  628. # in the body, so they dont render twice
  629. if node.name in body_identifiers.closuredefs:
  630. del body_identifiers.closuredefs[node.name]
  631. vis = DefVisitor()
  632. for n in node.nodes:
  633. n.accept_visitor(vis)
  634. self.identifier_stack.pop()
  635. bodyargs = node.body_decl.get_argument_expressions()
  636. self.printer.writeline("def body(%s):" % ','.join(bodyargs))
  637. # TODO: figure out best way to specify
  638. # buffering/nonbuffering (at call time would be better)
  639. buffered = False
  640. if buffered:
  641. self.printer.writelines(
  642. "context._push_buffer()",
  643. "try:"
  644. )
  645. self.write_variable_declares(body_identifiers)
  646. self.identifier_stack.append(body_identifiers)
  647. for n in node.nodes:
  648. n.accept_visitor(self)
  649. self.identifier_stack.pop()
  650. self.write_def_finish(node, buffered, False, False, callstack=False)
  651. self.printer.writelines(
  652. None,
  653. "return [%s]" % (','.join(export)),
  654. None
  655. )
  656. self.printer.writelines(
  657. # get local reference to current caller, if any
  658. "caller = context.caller_stack._get_caller()",
  659. # push on caller for nested call
  660. "context.caller_stack.nextcaller = "
  661. "runtime.Namespace('caller', context, callables=ccall(caller))",
  662. "try:")
  663. self.write_source_comment(node)
  664. self.printer.writelines(
  665. "__M_writer(%s)" % self.create_filter_callable([], node.expression, True),
  666. "finally:",
  667. "context.caller_stack.nextcaller = None",
  668. None
  669. )
  670. class _Identifiers(object):
  671. """tracks the status of identifier names as template code is rendered."""
  672. def __init__(self, node=None, parent=None, nested=False):
  673. if parent is not None:
  674. # if we are the branch created in write_namespaces(),
  675. # we don't share any context from the main body().
  676. if isinstance(node, parsetree.NamespaceTag):
  677. self.declared = set()
  678. self.topleveldefs = util.SetLikeDict()
  679. else:
  680. # things that have already been declared
  681. # in an enclosing namespace (i.e. names we can just use)
  682. self.declared = set(parent.declared).\
  683. union([c.name for c in parent.closuredefs.values()]).\
  684. union(parent.locally_declared).\
  685. union(parent.argument_declared)
  686. # if these identifiers correspond to a "nested"
  687. # scope, it means whatever the parent identifiers
  688. # had as undeclared will have been declared by that parent,
  689. # and therefore we have them in our scope.
  690. if nested:
  691. self.declared = self.declared.union(parent.undeclared)
  692. # top level defs that are available
  693. self.topleveldefs = util.SetLikeDict(**parent.topleveldefs)
  694. else:
  695. self.declared = set()
  696. self.topleveldefs = util.SetLikeDict()
  697. # things within this level that are referenced before they
  698. # are declared (e.g. assigned to)
  699. self.undeclared = set()
  700. # things that are declared locally. some of these things
  701. # could be in the "undeclared" list as well if they are
  702. # referenced before declared
  703. self.locally_declared = set()
  704. # assignments made in explicit python blocks.
  705. # these will be propagated to
  706. # the context of local def calls.
  707. self.locally_assigned = set()
  708. # things that are declared in the argument
  709. # signature of the def callable
  710. self.argument_declared = set()
  711. # closure defs that are defined in this level
  712. self.closuredefs = util.SetLikeDict()
  713. self.node = node
  714. if node is not None:
  715. node.accept_visitor(self)
  716. def branch(self, node, **kwargs):
  717. """create a new Identifiers for a new Node, with
  718. this Identifiers as the parent."""
  719. return _Identifiers(node, self, **kwargs)
  720. @property
  721. def defs(self):
  722. return set(self.topleveldefs.union(self.closuredefs).values())
  723. def __repr__(self):
  724. return "Identifiers(declared=%r, locally_declared=%r, "\
  725. "undeclared=%r, topleveldefs=%r, closuredefs=%r, argumentdeclared=%r)" %\
  726. (
  727. list(self.declared),
  728. list(self.locally_declared),
  729. list(self.undeclared),
  730. [c.name for c in self.topleveldefs.values()],
  731. [c.name for c in self.closuredefs.values()],
  732. self.argument_declared)
  733. def check_declared(self, node):
  734. """update the state of this Identifiers with the undeclared
  735. and declared identifiers of the given node."""
  736. for ident in node.undeclared_identifiers():
  737. if ident != 'context' and ident not in self.declared.union(self.locally_declared):
  738. self.undeclared.add(ident)
  739. for ident in node.declared_identifiers():
  740. self.locally_declared.add(ident)
  741. def add_declared(self, ident):
  742. self.declared.add(ident)
  743. if ident in self.undeclared:
  744. self.undeclared.remove(ident)
  745. def visitExpression(self, node):
  746. self.check_declared(node)
  747. def visitControlLine(self, node):
  748. self.check_declared(node)
  749. def visitCode(self, node):
  750. if not node.ismodule:
  751. self.check_declared(node)
  752. self.locally_assigned = self.locally_assigned.union(node.declared_identifiers())
  753. def visitNamespaceTag(self, node):
  754. # only traverse into the sub-elements of a
  755. # <%namespace> tag if we are the branch created in
  756. # write_namespaces()
  757. if self.node is node:
  758. for n in node.nodes:
  759. n.accept_visitor(self)
  760. def visitDefTag(self, node):
  761. if node.is_root():
  762. self.topleveldefs[node.name] = node
  763. elif node is not self.node:
  764. self.closuredefs[node.name] = node
  765. for ident in node.undeclared_identifiers():
  766. if ident != 'context' and ident not in self.declared.union(self.locally_declared):
  767. self.undeclared.add(ident)
  768. # visit defs only one level deep
  769. if node is self.node:
  770. for ident in node.declared_identifiers():
  771. self.argument_declared.add(ident)
  772. for n in node.nodes:
  773. n.accept_visitor(self)
  774. def visitIncludeTag(self, node):
  775. self.check_declared(node)
  776. def visitPageTag(self, node):
  777. for ident in node.declared_identifiers():
  778. self.argument_declared.add(ident)
  779. self.check_declared(node)
  780. def visitCallNamespaceTag(self, node):
  781. self.visitCallTag(node)
  782. def visitCallTag(self, node):
  783. if node is self.node:
  784. for ident in node.undeclared_identifiers():
  785. if ident != 'context' and ident not in self.declared.union(self.locally_declared):
  786. self.undeclared.add(ident)
  787. for ident in node.declared_identifiers():
  788. self.argument_declared.add(ident)
  789. for n in node.nodes:
  790. n.accept_visitor(self)
  791. else:
  792. for ident in node.undeclared_identifiers():
  793. if ident != 'context' and ident not in self.declared.union(self.locally_declared):
  794. self.undeclared.add(ident)