Mercurial > hg
view mercurial/templateutil.py @ 37163:0fb28899e81a
templater: factor out unwrapastype() from evalastype()
So ParseError of unwrapastype() can be caught reliably.
author | Yuya Nishihara <yuya@tcha.org> |
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date | Fri, 23 Mar 2018 20:43:55 +0900 |
parents | 9ab3491f84c2 |
children | 54355c243042 |
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# templateutil.py - utility for template evaluation # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import types from .i18n import _ from . import ( error, pycompat, util, ) from .utils import ( stringutil, ) class ResourceUnavailable(error.Abort): pass class TemplateNotFound(error.Abort): pass class hybrid(object): """Wrapper for list or dict to support legacy template This class allows us to handle both: - "{files}" (legacy command-line-specific list hack) and - "{files % '{file}\n'}" (hgweb-style with inlining and function support) and to access raw values: - "{ifcontains(file, files, ...)}", "{ifcontains(key, extras, ...)}" - "{get(extras, key)}" - "{files|json}" """ def __init__(self, gen, values, makemap, joinfmt, keytype=None): if gen is not None: self.gen = gen # generator or function returning generator self._values = values self._makemap = makemap self.joinfmt = joinfmt self.keytype = keytype # hint for 'x in y' where type(x) is unresolved def gen(self): """Default generator to stringify this as {join(self, ' ')}""" for i, x in enumerate(self._values): if i > 0: yield ' ' yield self.joinfmt(x) def itermaps(self): makemap = self._makemap for x in self._values: yield makemap(x) def __contains__(self, x): return x in self._values def __getitem__(self, key): return self._values[key] def __len__(self): return len(self._values) def __iter__(self): return iter(self._values) def __getattr__(self, name): if name not in (r'get', r'items', r'iteritems', r'iterkeys', r'itervalues', r'keys', r'values'): raise AttributeError(name) return getattr(self._values, name) class mappable(object): """Wrapper for non-list/dict object to support map operation This class allows us to handle both: - "{manifest}" - "{manifest % '{rev}:{node}'}" - "{manifest.rev}" Unlike a hybrid, this does not simulate the behavior of the underling value. Use unwrapvalue(), unwrapastype(), or unwraphybrid() to obtain the inner object. """ def __init__(self, gen, key, value, makemap): if gen is not None: self.gen = gen # generator or function returning generator self._key = key self._value = value # may be generator of strings self._makemap = makemap def gen(self): yield pycompat.bytestr(self._value) def tomap(self): return self._makemap(self._key) def itermaps(self): yield self.tomap() def hybriddict(data, key='key', value='value', fmt=None, gen=None): """Wrap data to support both dict-like and string-like operations""" prefmt = pycompat.identity if fmt is None: fmt = '%s=%s' prefmt = pycompat.bytestr return hybrid(gen, data, lambda k: {key: k, value: data[k]}, lambda k: fmt % (prefmt(k), prefmt(data[k]))) def hybridlist(data, name, fmt=None, gen=None): """Wrap data to support both list-like and string-like operations""" prefmt = pycompat.identity if fmt is None: fmt = '%s' prefmt = pycompat.bytestr return hybrid(gen, data, lambda x: {name: x}, lambda x: fmt % prefmt(x)) def unwraphybrid(thing): """Return an object which can be stringified possibly by using a legacy template""" gen = getattr(thing, 'gen', None) if gen is None: return thing if callable(gen): return gen() return gen def unwrapvalue(thing): """Move the inner value object out of the wrapper""" if not util.safehasattr(thing, '_value'): return thing return thing._value def wraphybridvalue(container, key, value): """Wrap an element of hybrid container to be mappable The key is passed to the makemap function of the given container, which should be an item generated by iter(container). """ makemap = getattr(container, '_makemap', None) if makemap is None: return value if util.safehasattr(value, '_makemap'): # a nested hybrid list/dict, which has its own way of map operation return value return mappable(None, key, value, makemap) def compatdict(context, mapping, name, data, key='key', value='value', fmt=None, plural=None, separator=' '): """Wrap data like hybriddict(), but also supports old-style list template This exists for backward compatibility with the old-style template. Use hybriddict() for new template keywords. """ c = [{key: k, value: v} for k, v in data.iteritems()] f = _showcompatlist(context, mapping, name, c, plural, separator) return hybriddict(data, key=key, value=value, fmt=fmt, gen=f) def compatlist(context, mapping, name, data, element=None, fmt=None, plural=None, separator=' '): """Wrap data like hybridlist(), but also supports old-style list template This exists for backward compatibility with the old-style template. Use hybridlist() for new template keywords. """ f = _showcompatlist(context, mapping, name, data, plural, separator) return hybridlist(data, name=element or name, fmt=fmt, gen=f) def _showcompatlist(context, mapping, name, values, plural=None, separator=' '): """Return a generator that renders old-style list template name is name of key in template map. values is list of strings or dicts. plural is plural of name, if not simply name + 's'. separator is used to join values as a string expansion works like this, given name 'foo'. if values is empty, expand 'no_foos'. if 'foo' not in template map, return values as a string, joined by 'separator'. expand 'start_foos'. for each value, expand 'foo'. if 'last_foo' in template map, expand it instead of 'foo' for last key. expand 'end_foos'. """ if not plural: plural = name + 's' if not values: noname = 'no_' + plural if context.preload(noname): yield context.process(noname, mapping) return if not context.preload(name): if isinstance(values[0], bytes): yield separator.join(values) else: for v in values: r = dict(v) r.update(mapping) yield r return startname = 'start_' + plural if context.preload(startname): yield context.process(startname, mapping) def one(v, tag=name): vmapping = {} try: vmapping.update(v) # Python 2 raises ValueError if the type of v is wrong. Python # 3 raises TypeError. except (AttributeError, TypeError, ValueError): try: # Python 2 raises ValueError trying to destructure an e.g. # bytes. Python 3 raises TypeError. for a, b in v: vmapping[a] = b except (TypeError, ValueError): vmapping[name] = v vmapping = context.overlaymap(mapping, vmapping) return context.process(tag, vmapping) lastname = 'last_' + name if context.preload(lastname): last = values.pop() else: last = None for v in values: yield one(v) if last is not None: yield one(last, tag=lastname) endname = 'end_' + plural if context.preload(endname): yield context.process(endname, mapping) def flatten(thing): """Yield a single stream from a possibly nested set of iterators""" thing = unwraphybrid(thing) if isinstance(thing, bytes): yield thing elif isinstance(thing, str): # We can only hit this on Python 3, and it's here to guard # against infinite recursion. raise error.ProgrammingError('Mercurial IO including templates is done' ' with bytes, not strings, got %r' % thing) elif thing is None: pass elif not util.safehasattr(thing, '__iter__'): yield pycompat.bytestr(thing) else: for i in thing: i = unwraphybrid(i) if isinstance(i, bytes): yield i elif i is None: pass elif not util.safehasattr(i, '__iter__'): yield pycompat.bytestr(i) else: for j in flatten(i): yield j def stringify(thing): """Turn values into bytes by converting into text and concatenating them""" if isinstance(thing, bytes): return thing # retain localstr to be round-tripped return b''.join(flatten(thing)) def findsymbolicname(arg): """Find symbolic name for the given compiled expression; returns None if nothing found reliably""" while True: func, data = arg if func is runsymbol: return data elif func is runfilter: arg = data[0] else: return None def evalrawexp(context, mapping, arg): """Evaluate given argument as a bare template object which may require further processing (such as folding generator of strings)""" func, data = arg return func(context, mapping, data) def evalfuncarg(context, mapping, arg): """Evaluate given argument as value type""" return _unwrapvalue(evalrawexp(context, mapping, arg)) # TODO: unify this with unwrapvalue() once the bug of templatefunc.join() # is fixed. we can't do that right now because join() has to take a generator # of byte strings as it is, not a lazy byte string. def _unwrapvalue(thing): thing = unwrapvalue(thing) # evalrawexp() may return string, generator of strings or arbitrary object # such as date tuple, but filter does not want generator. if isinstance(thing, types.GeneratorType): thing = stringify(thing) return thing def evalboolean(context, mapping, arg): """Evaluate given argument as boolean, but also takes boolean literals""" func, data = arg if func is runsymbol: thing = func(context, mapping, data, default=None) if thing is None: # not a template keyword, takes as a boolean literal thing = stringutil.parsebool(data) else: thing = func(context, mapping, data) thing = unwrapvalue(thing) if isinstance(thing, bool): return thing # other objects are evaluated as strings, which means 0 is True, but # empty dict/list should be False as they are expected to be '' return bool(stringify(thing)) def evalinteger(context, mapping, arg, err=None): return unwrapinteger(evalrawexp(context, mapping, arg), err) def unwrapinteger(thing, err=None): thing = _unwrapvalue(thing) try: return int(thing) except (TypeError, ValueError): raise error.ParseError(err or _('not an integer')) def evalstring(context, mapping, arg): return stringify(evalrawexp(context, mapping, arg)) def evalstringliteral(context, mapping, arg): """Evaluate given argument as string template, but returns symbol name if it is unknown""" func, data = arg if func is runsymbol: thing = func(context, mapping, data, default=data) else: thing = func(context, mapping, data) return stringify(thing) _unwrapfuncbytype = { bytes: stringify, int: unwrapinteger, } def unwrapastype(thing, typ): """Move the inner value object out of the wrapper and coerce its type""" try: f = _unwrapfuncbytype[typ] except KeyError: raise error.ProgrammingError('invalid type specified: %r' % typ) return f(thing) def runinteger(context, mapping, data): return int(data) def runstring(context, mapping, data): return data def _recursivesymbolblocker(key): def showrecursion(**args): raise error.Abort(_("recursive reference '%s' in template") % key) return showrecursion def runsymbol(context, mapping, key, default=''): v = context.symbol(mapping, key) if v is None: # put poison to cut recursion. we can't move this to parsing phase # because "x = {x}" is allowed if "x" is a keyword. (issue4758) safemapping = mapping.copy() safemapping[key] = _recursivesymbolblocker(key) try: v = context.process(key, safemapping) except TemplateNotFound: v = default if callable(v) and getattr(v, '_requires', None) is None: # old templatekw: expand all keywords and resources # (TODO: deprecate this after porting web template keywords to new API) props = {k: context._resources.lookup(context, mapping, k) for k in context._resources.knownkeys()} # pass context to _showcompatlist() through templatekw._showlist() props['templ'] = context props.update(mapping) return v(**pycompat.strkwargs(props)) if callable(v): # new templatekw try: return v(context, mapping) except ResourceUnavailable: # unsupported keyword is mapped to empty just like unknown keyword return None return v def runtemplate(context, mapping, template): for arg in template: yield evalrawexp(context, mapping, arg) def runfilter(context, mapping, data): arg, filt = data thing = evalfuncarg(context, mapping, arg) try: return filt(thing) except (ValueError, AttributeError, TypeError): sym = findsymbolicname(arg) if sym: msg = (_("template filter '%s' is not compatible with keyword '%s'") % (pycompat.sysbytes(filt.__name__), sym)) else: msg = (_("incompatible use of template filter '%s'") % pycompat.sysbytes(filt.__name__)) raise error.Abort(msg) def runmap(context, mapping, data): darg, targ = data d = evalrawexp(context, mapping, darg) if util.safehasattr(d, 'itermaps'): diter = d.itermaps() else: try: diter = iter(d) except TypeError: sym = findsymbolicname(darg) if sym: raise error.ParseError(_("keyword '%s' is not iterable") % sym) else: raise error.ParseError(_("%r is not iterable") % d) for i, v in enumerate(diter): if isinstance(v, dict): lm = context.overlaymap(mapping, v) lm['index'] = i yield evalrawexp(context, lm, targ) else: # v is not an iterable of dicts, this happen when 'key' # has been fully expanded already and format is useless. # If so, return the expanded value. yield v def runmember(context, mapping, data): darg, memb = data d = evalrawexp(context, mapping, darg) if util.safehasattr(d, 'tomap'): lm = context.overlaymap(mapping, d.tomap()) return runsymbol(context, lm, memb) if util.safehasattr(d, 'get'): return getdictitem(d, memb) sym = findsymbolicname(darg) if sym: raise error.ParseError(_("keyword '%s' has no member") % sym) else: raise error.ParseError(_("%r has no member") % pycompat.bytestr(d)) def runnegate(context, mapping, data): data = evalinteger(context, mapping, data, _('negation needs an integer argument')) return -data def runarithmetic(context, mapping, data): func, left, right = data left = evalinteger(context, mapping, left, _('arithmetic only defined on integers')) right = evalinteger(context, mapping, right, _('arithmetic only defined on integers')) try: return func(left, right) except ZeroDivisionError: raise error.Abort(_('division by zero is not defined')) def getdictitem(dictarg, key): val = dictarg.get(key) if val is None: return return wraphybridvalue(dictarg, key, val)