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