1 ##############################################################################
2 #
3 # Copyright (c) 2001, 2002 Zope Corporation and Contributors.
4 # All Rights Reserved.
5 #
6 # This software is subject to the provisions of the Zope Public License,
7 # Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
8 # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
9 # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
10 # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
11 # FOR A PARTICULAR PURPOSE
12 #
13 ##############################################################################
14 """
15 Interpreter for a pre-compiled TAL program.
16 """
18 import sys
19 import getopt
21 from cgi import escape
22 from string import join, lower, rfind
23 try:
24 from strop import lower, rfind
25 except ImportError:
26 pass
28 try:
29 from cStringIO import StringIO
30 except ImportError:
31 from StringIO import StringIO
33 from TALDefs import quote, TAL_VERSION, TALError, METALError
34 from TALDefs import isCurrentVersion, getProgramVersion, getProgramMode
35 from TALGenerator import TALGenerator
37 BOOLEAN_HTML_ATTRS = [
38 # List of Boolean attributes in HTML that should be rendered in
39 # minimized form (e.g. <img ismap> rather than <img ismap="">)
40 # From http://www.w3.org/TR/xhtml1/#guidelines (C.10)
41 # XXX The problem with this is that this is not valid XML and
42 # can't be parsed back!
43 "compact", "nowrap", "ismap", "declare", "noshade", "checked",
44 "disabled", "readonly", "multiple", "selected", "noresize",
45 "defer"
46 ]
48 EMPTY_HTML_TAGS = [
49 # List of HTML tags with an empty content model; these are
50 # rendered in minimized form, e.g. <img />.
51 # From http://www.w3.org/TR/xhtml1/#dtds
52 "base", "meta", "link", "hr", "br", "param", "img", "area",
53 "input", "col", "basefont", "isindex", "frame",
54 ]
56 class AltTALGenerator(TALGenerator):
58 def __init__(self, repldict, expressionCompiler=None, xml=0):
59 self.repldict = repldict
60 self.enabled = 1
61 TALGenerator.__init__(self, expressionCompiler, xml)
63 def enable(self, enabled):
64 self.enabled = enabled
66 def emit(self, *args):
67 if self.enabled:
68 apply(TALGenerator.emit, (self,) + args)
70 def emitStartElement(self, name, attrlist, taldict, metaldict,
71 position=(None, None), isend=0):
72 metaldict = {}
73 taldict = {}
74 if self.enabled and self.repldict:
75 taldict["attributes"] = "x x"
76 TALGenerator.emitStartElement(self, name, attrlist,
77 taldict, metaldict, position, isend)
79 def replaceAttrs(self, attrlist, repldict):
80 if self.enabled and self.repldict:
81 repldict = self.repldict
82 self.repldict = None
83 return TALGenerator.replaceAttrs(self, attrlist, repldict)
86 class TALInterpreter:
88 def __init__(self, program, macros, engine, stream=None,
89 debug=0, wrap=60, metal=1, tal=1, showtal=-1,
90 strictinsert=1, stackLimit=100):
91 self.program = program
92 self.macros = macros
93 self.engine = engine
94 self.Default = engine.getDefault()
95 self.stream = stream or sys.stdout
96 self._stream_write = self.stream.write
97 self.debug = debug
98 self.wrap = wrap
99 self.metal = metal
100 self.tal = tal
101 if tal:
102 self.dispatch = self.bytecode_handlers_tal
103 else:
104 self.dispatch = self.bytecode_handlers
105 assert showtal in (-1, 0, 1)
106 if showtal == -1:
107 showtal = (not tal)
108 self.showtal = showtal
109 self.strictinsert = strictinsert
110 self.stackLimit = stackLimit
111 self.html = 0
112 self.endsep = "/>"
113 self.endlen = len(self.endsep)
114 self.macroStack = []
115 self.popMacro = self.macroStack.pop
116 self.position = None, None # (lineno, offset)
117 self.col = 0
118 self.level = 0
119 self.scopeLevel = 0
120 self.sourceFile = None
122 def saveState(self):
123 return (self.position, self.col, self.stream,
124 self.scopeLevel, self.level)
126 def restoreState(self, state):
127 (self.position, self.col, self.stream, scopeLevel, level) = state
128 self._stream_write = self.stream.write
129 assert self.level == level
130 while self.scopeLevel > scopeLevel:
131 self.engine.endScope()
132 self.scopeLevel = self.scopeLevel - 1
133 self.engine.setPosition(self.position)
135 def restoreOutputState(self, state):
136 (dummy, self.col, self.stream, scopeLevel, level) = state
137 self._stream_write = self.stream.write
138 assert self.level == level
139 assert self.scopeLevel == scopeLevel
141 def pushMacro(self, macroName, slots, entering=1):
142 if len(self.macroStack) >= self.stackLimit:
143 raise METALError("macro nesting limit (%d) exceeded "
144 "by %s" % (self.stackLimit, `macroName`))
145 self.macroStack.append([macroName, slots, entering])
147 def macroContext(self, what):
148 macroStack = self.macroStack
149 i = len(macroStack)
150 while i > 0:
151 i = i-1
152 if macroStack[i][0] == what:
153 return i
154 return -1
156 def __call__(self):
157 assert self.level == 0
158 assert self.scopeLevel == 0
159 self.interpret(self.program)
160 assert self.level == 0
161 assert self.scopeLevel == 0
162 if self.col > 0:
163 self._stream_write("\n")
164 self.col = 0
166 def stream_write(self, s,
167 len=len, rfind=rfind):
168 self._stream_write(s)
169 i = rfind(s, '\n')
170 if i < 0:
171 self.col = self.col + len(s)
172 else:
173 self.col = len(s) - (i + 1)
175 bytecode_handlers = {}
177 def interpret(self, program, None=None):
178 oldlevel = self.level
179 self.level = oldlevel + 1
180 handlers = self.dispatch
181 try:
182 if self.debug:
183 for (opcode, args) in program:
184 s = "%sdo_%s%s\n" % (" "*self.level, opcode,
185 repr(args))
186 if len(s) > 80:
187 s = s[:76] + "...\n"
188 sys.stderr.write(s)
189 handlers[opcode](self, args)
190 else:
191 for (opcode, args) in program:
192 handlers[opcode](self, args)
193 finally:
194 self.level = oldlevel
196 def do_version(self, version):
197 assert version == TAL_VERSION
198 bytecode_handlers["version"] = do_version
200 def do_mode(self, mode):
201 assert mode in ("html", "xml")
202 self.html = (mode == "html")
203 if self.html:
204 self.endsep = " />"
205 else:
206 self.endsep = "/>"
207 self.endlen = len(self.endsep)
208 bytecode_handlers["mode"] = do_mode
210 def do_setSourceFile(self, source_file):
211 self.sourceFile = source_file
212 self.engine.setSourceFile(source_file)
213 bytecode_handlers["setSourceFile"] = do_setSourceFile
215 def do_setPosition(self, position):
216 self.position = position
217 self.engine.setPosition(position)
218 bytecode_handlers["setPosition"] = do_setPosition
220 def do_startEndTag(self, stuff):
221 self.do_startTag(stuff, self.endsep, self.endlen)
222 bytecode_handlers["startEndTag"] = do_startEndTag
224 def do_startTag(self, (name, attrList),
225 end=">", endlen=1, _len=len):
226 # The bytecode generator does not cause calls to this method
227 # for start tags with no attributes; those are optimized down
228 # to rawtext events. Hence, there is no special "fast path"
229 # for that case.
230 _stream_write = self._stream_write
231 _stream_write("<" + name)
232 namelen = _len(name)
233 col = self.col + namelen + 1
234 wrap = self.wrap
235 align = col + 1
236 if align >= wrap/2:
237 align = 4 # Avoid a narrow column far to the right
238 attrAction = self.dispatch["<attrAction>"]
239 try:
240 for item in attrList:
241 if _len(item) == 2:
242 name, s = item
243 else:
244 ok, name, s = attrAction(self, item)
245 if not ok:
246 continue
247 slen = _len(s)
248 if (wrap and
249 col >= align and
250 col + 1 + slen > wrap):
251 _stream_write("\n" + " "*align)
252 col = align + slen
253 else:
254 s = " " + s
255 col = col + 1 + slen
256 _stream_write(s)
257 _stream_write(end)
258 col = col + endlen
259 finally:
260 self.col = col
261 bytecode_handlers["startTag"] = do_startTag
263 def attrAction(self, item):
264 name, value, action = item[:3]
265 if action == 1 or (action > 1 and not self.showtal):
266 return 0, name, value
267 macs = self.macroStack
268 if action == 2 and self.metal and macs:
269 if len(macs) > 1 or not macs[-1][2]:
270 # Drop all METAL attributes at a use-depth above one.
271 return 0, name, value
272 # Clear 'entering' flag
273 macs[-1][2] = 0
274 # Convert or drop depth-one METAL attributes.
275 i = rfind(name, ":") + 1
276 prefix, suffix = name[:i], name[i:]
277 if suffix == "define-macro":
278 # Convert define-macro as we enter depth one.
279 name = prefix + "use-macro"
280 value = macs[-1][0] # Macro name
281 elif suffix == "define-slot":
282 name = prefix + "slot"
283 elif suffix == "fill-slot":
284 pass
285 else:
286 return 0, name, value
288 if value is None:
289 value = name
290 else:
291 value = "%s=%s" % (name, quote(value))
292 return 1, name, value
294 def attrAction_tal(self, item):
295 name, value, action = item[:3]
296 if action > 1:
297 return self.attrAction(item)
298 ok = 1
299 if self.html and lower(name) in BOOLEAN_HTML_ATTRS:
300 evalue = self.engine.evaluateBoolean(item[3])
301 if evalue is self.Default:
302 if action == 1: # Cancelled insert
303 ok = 0
304 elif evalue:
305 value = None
306 else:
307 ok = 0
308 else:
309 evalue = self.engine.evaluateText(item[3])
310 if evalue is self.Default:
311 if action == 1: # Cancelled insert
312 ok = 0
313 else:
314 if evalue is None:
315 ok = 0
316 value = evalue
317 if ok:
318 if value is None:
319 value = name
320 value = "%s=%s" % (name, quote(value))
321 return ok, name, value
323 bytecode_handlers["<attrAction>"] = attrAction
325 def no_tag(self, start, program):
326 state = self.saveState()
327 self.stream = stream = StringIO()
328 self._stream_write = stream.write
329 self.interpret(start)
330 self.restoreOutputState(state)
331 self.interpret(program)
333 def do_optTag(self, (name, cexpr, tag_ns, isend, start, program),
334 omit=0):
335 if tag_ns and not self.showtal:
336 return self.no_tag(start, program)
338 self.interpret(start)
339 if not isend:
340 self.interpret(program)
341 s = '</%s>' % name
342 self._stream_write(s)
343 self.col = self.col + len(s)
345 def do_optTag_tal(self, stuff):
346 cexpr = stuff[1]
347 if cexpr is not None and (cexpr == '' or
348 self.engine.evaluateBoolean(cexpr)):
349 self.no_tag(stuff[-2], stuff[-1])
350 else:
351 self.do_optTag(stuff)
352 bytecode_handlers["optTag"] = do_optTag
354 def dumpMacroStack(self, prefix, suffix, value):
355 sys.stderr.write("+---- %s%s = %s\n" % (prefix, suffix, value))
356 for i in range(len(self.macroStack)):
357 what, macroName, slots = self.macroStack[i]
358 sys.stderr.write("| %2d. %-12s %-12s %s\n" %
359 (i, what, macroName, slots and slots.keys()))
360 sys.stderr.write("+--------------------------------------\n")
362 def do_rawtextBeginScope(self, (s, col, position, closeprev, dict)):
363 self._stream_write(s)
364 self.col = col
365 self.do_setPosition(position)
366 if closeprev:
367 engine = self.engine
368 engine.endScope()
369 engine.beginScope()
370 else:
371 self.engine.beginScope()
372 self.scopeLevel = self.scopeLevel + 1
374 def do_rawtextBeginScope_tal(self, (s, col, position, closeprev, dict)):
375 self._stream_write(s)
376 self.col = col
377 self.do_setPosition(position)
378 engine = self.engine
379 if closeprev:
380 engine.endScope()
381 engine.beginScope()
382 else:
383 engine.beginScope()
384 self.scopeLevel = self.scopeLevel + 1
385 engine.setLocal("attrs", dict)
386 bytecode_handlers["rawtextBeginScope"] = do_rawtextBeginScope
388 def do_beginScope(self, dict):
389 self.engine.beginScope()
390 self.scopeLevel = self.scopeLevel + 1
392 def do_beginScope_tal(self, dict):
393 engine = self.engine
394 engine.beginScope()
395 engine.setLocal("attrs", dict)
396 self.scopeLevel = self.scopeLevel + 1
397 bytecode_handlers["beginScope"] = do_beginScope
399 def do_endScope(self, notused=None):
400 self.engine.endScope()
401 self.scopeLevel = self.scopeLevel - 1
402 bytecode_handlers["endScope"] = do_endScope
404 def do_setLocal(self, notused):
405 pass
407 def do_setLocal_tal(self, (name, expr)):
408 self.engine.setLocal(name, self.engine.evaluateValue(expr))
409 bytecode_handlers["setLocal"] = do_setLocal
411 def do_setGlobal_tal(self, (name, expr)):
412 self.engine.setGlobal(name, self.engine.evaluateValue(expr))
413 bytecode_handlers["setGlobal"] = do_setLocal
415 def do_insertText(self, stuff):
416 self.interpret(stuff[1])
418 def do_insertText_tal(self, stuff):
419 text = self.engine.evaluateText(stuff[0])
420 if text is None:
421 return
422 if text is self.Default:
423 self.interpret(stuff[1])
424 return
425 s = escape(text)
426 self._stream_write(s)
427 i = rfind(s, '\n')
428 if i < 0:
429 self.col = self.col + len(s)
430 else:
431 self.col = len(s) - (i + 1)
432 bytecode_handlers["insertText"] = do_insertText
434 def do_insertStructure(self, stuff):
435 self.interpret(stuff[2])
437 def do_insertStructure_tal(self, (expr, repldict, block)):
438 structure = self.engine.evaluateStructure(expr)
439 if structure is None:
440 return
441 if structure is self.Default:
442 self.interpret(block)
443 return
444 text = str(structure)
445 if not (repldict or self.strictinsert):
446 # Take a shortcut, no error checking
447 self.stream_write(text)
448 return
449 if self.html:
450 self.insertHTMLStructure(text, repldict)
451 else:
452 self.insertXMLStructure(text, repldict)
453 bytecode_handlers["insertStructure"] = do_insertStructure
455 def insertHTMLStructure(self, text, repldict):
456 from HTMLTALParser import HTMLTALParser
457 gen = AltTALGenerator(repldict, self.engine, 0)
458 p = HTMLTALParser(gen) # Raises an exception if text is invalid
459 p.parseString(text)
460 program, macros = p.getCode()
461 self.interpret(program)
463 def insertXMLStructure(self, text, repldict):
464 from TALParser import TALParser
465 gen = AltTALGenerator(repldict, self.engine, 0)
466 p = TALParser(gen)
467 gen.enable(0)
468 p.parseFragment('<!DOCTYPE foo PUBLIC "foo" "bar"><foo>')
469 gen.enable(1)
470 p.parseFragment(text) # Raises an exception if text is invalid
471 gen.enable(0)
472 p.parseFragment('</foo>', 1)
473 program, macros = gen.getCode()
474 self.interpret(program)
476 def do_loop(self, (name, expr, block)):
477 self.interpret(block)
479 def do_loop_tal(self, (name, expr, block)):
480 iterator = self.engine.setRepeat(name, expr)
481 while iterator.next():
482 self.interpret(block)
483 bytecode_handlers["loop"] = do_loop
485 def do_rawtextColumn(self, (s, col)):
486 self._stream_write(s)
487 self.col = col
488 bytecode_handlers["rawtextColumn"] = do_rawtextColumn
490 def do_rawtextOffset(self, (s, offset)):
491 self._stream_write(s)
492 self.col = self.col + offset
493 bytecode_handlers["rawtextOffset"] = do_rawtextOffset
495 def do_condition(self, (condition, block)):
496 if not self.tal or self.engine.evaluateBoolean(condition):
497 self.interpret(block)
498 bytecode_handlers["condition"] = do_condition
500 def do_defineMacro(self, (macroName, macro)):
501 macs = self.macroStack
502 if len(macs) == 1:
503 entering = macs[-1][2]
504 if not entering:
505 macs.append(None)
506 self.interpret(macro)
507 macs.pop()
508 return
509 self.interpret(macro)
510 bytecode_handlers["defineMacro"] = do_defineMacro
512 def do_useMacro(self, (macroName, macroExpr, compiledSlots, block)):
513 if not self.metal:
514 self.interpret(block)
515 return
516 macro = self.engine.evaluateMacro(macroExpr)
517 if macro is self.Default:
518 macro = block
519 else:
520 if not isCurrentVersion(macro):
521 raise METALError("macro %s has incompatible version %s" %
522 (`macroName`, `getProgramVersion(macro)`),
523 self.position)
524 mode = getProgramMode(macro)
525 if mode != (self.html and "html" or "xml"):
526 raise METALError("macro %s has incompatible mode %s" %
527 (`macroName`, `mode`), self.position)
528 self.pushMacro(macroName, compiledSlots)
529 saved_source = self.sourceFile
530 saved_position = self.position # Used by Boa Constructor
531 self.interpret(macro)
532 if self.sourceFile != saved_source:
533 self.engine.setSourceFile(saved_source)
534 self.sourceFile = saved_source
535 self.popMacro()
536 bytecode_handlers["useMacro"] = do_useMacro
538 def do_fillSlot(self, (slotName, block)):
539 # This is only executed if the enclosing 'use-macro' evaluates
540 # to 'default'.
541 self.interpret(block)
542 bytecode_handlers["fillSlot"] = do_fillSlot
544 def do_defineSlot(self, (slotName, block)):
545 if not self.metal:
546 self.interpret(block)
547 return
548 macs = self.macroStack
549 if macs and macs[-1] is not None:
550 saved_source = self.sourceFile
551 saved_position = self.position # Used by Boa Constructor
552 macroName, slots = self.popMacro()[:2]
553 slot = slots.get(slotName)
554 if slot is not None:
555 self.interpret(slot)
556 if self.sourceFile != saved_source:
557 self.engine.setSourceFile(saved_source)
558 self.sourceFile = saved_source
559 self.pushMacro(macroName, slots, entering=0)
560 return
561 self.pushMacro(macroName, slots)
562 if len(macs) == 1:
563 self.interpret(block)
564 return
565 self.interpret(block)
566 bytecode_handlers["defineSlot"] = do_defineSlot
568 def do_onError(self, (block, handler)):
569 self.interpret(block)
571 def do_onError_tal(self, (block, handler)):
572 state = self.saveState()
573 self.stream = stream = StringIO()
574 self._stream_write = stream.write
575 try:
576 self.interpret(block)
577 except:
578 exc = sys.exc_info()[1]
579 self.restoreState(state)
580 engine = self.engine
581 engine.beginScope()
582 error = engine.createErrorInfo(exc, self.position)
583 engine.setLocal('error', error)
584 try:
585 self.interpret(handler)
586 finally:
587 engine.endScope()
588 else:
589 self.restoreOutputState(state)
590 self.stream_write(stream.getvalue())
591 bytecode_handlers["onError"] = do_onError
593 bytecode_handlers_tal = bytecode_handlers.copy()
594 bytecode_handlers_tal["rawtextBeginScope"] = do_rawtextBeginScope_tal
595 bytecode_handlers_tal["beginScope"] = do_beginScope_tal
596 bytecode_handlers_tal["setLocal"] = do_setLocal_tal
597 bytecode_handlers_tal["setGlobal"] = do_setGlobal_tal
598 bytecode_handlers_tal["insertStructure"] = do_insertStructure_tal
599 bytecode_handlers_tal["insertText"] = do_insertText_tal
600 bytecode_handlers_tal["loop"] = do_loop_tal
601 bytecode_handlers_tal["onError"] = do_onError_tal
602 bytecode_handlers_tal["<attrAction>"] = attrAction_tal
603 bytecode_handlers_tal["optTag"] = do_optTag_tal
606 def test():
607 from driver import FILE, parsefile
608 from DummyEngine import DummyEngine
609 try:
610 opts, args = getopt.getopt(sys.argv[1:], "")
611 except getopt.error, msg:
612 print msg
613 sys.exit(2)
614 if args:
615 file = args[0]
616 else:
617 file = FILE
618 doc = parsefile(file)
619 compiler = TALCompiler(doc)
620 program, macros = compiler()
621 engine = DummyEngine()
622 interpreter = TALInterpreter(program, macros, engine)
623 interpreter()
625 if __name__ == "__main__":
626 test()