templater: convert resources to a table of callables for future extension
I'm going to add a full templating support to the annotate command. As the
annotate is a filectx-oriented command, we'll need a way to look up a ctx
from a bounded fctx only when necessary.
This is the minimal change to support that. I'm thinking of defining a proper
interface to look up template resources to fix other issues, but that isn't
ready yet.
(Changes from V1: just updated tests and patch descriptions.)
# 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,
)
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() 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()]
t = context.resource(mapping, 'templ')
f = _showlist(name, c, t, mapping, 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.
"""
t = context.resource(mapping, 'templ')
f = _showlist(name, data, t, mapping, plural, separator)
return hybridlist(data, name=element or name, fmt=fmt, gen=f)
def _showlist(name, values, templ, mapping, plural=None, separator=' '):
'''expand set of values.
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'.
'''
strmapping = pycompat.strkwargs(mapping)
if not plural:
plural = name + 's'
if not values:
noname = 'no_' + plural
if noname in templ:
yield templ(noname, **strmapping)
return
if name not in templ:
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 startname in templ:
yield templ(startname, **strmapping)
vmapping = mapping.copy()
def one(v, tag=name):
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
return templ(tag, **pycompat.strkwargs(vmapping))
lastname = 'last_' + name
if lastname in templ:
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 endname in templ:
yield templ(endname, **strmapping)
def stringify(thing):
"""Turn values into bytes by converting into text and concatenating them"""
thing = unwraphybrid(thing)
if util.safehasattr(thing, '__iter__') and not isinstance(thing, bytes):
if isinstance(thing, str):
# This is only reachable on Python 3 (otherwise
# isinstance(thing, bytes) would have been true), and is
# here to prevent infinite recursion bugs on Python 3.
raise error.ProgrammingError(
'stringify got unexpected unicode string: %r' % thing)
return "".join([stringify(t) for t in thing if t is not None])
if thing is None:
return ""
return pycompat.bytestr(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"""
thing = evalrawexp(context, mapping, arg)
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 = util.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):
v = evalfuncarg(context, mapping, arg)
try:
return int(v)
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)
_evalfuncbytype = {
bool: evalboolean,
bytes: evalstring,
int: evalinteger,
}
def evalastype(context, mapping, arg, typ):
"""Evaluate given argument and coerce its type"""
try:
f = _evalfuncbytype[typ]
except KeyError:
raise error.ProgrammingError('invalid type specified: %r' % typ)
return f(context, mapping, arg)
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
props = {k: f(context, mapping, k)
for k, f in context._resources.items()}
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):
lm = mapping.copy()
lm['index'] = i
if isinstance(v, dict):
lm.update(v)
lm['originalnode'] = mapping.get('node')
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 = mapping.copy()
lm.update(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)