# templater.py - template expansion for output
#
# 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 i18n import _
import sys, os
import util, config, templatefilters
path = ['templates', '../templates']
stringify = templatefilters.stringify
def _flatten(thing):
'''yield a single stream from a possibly nested set of iterators'''
if isinstance(thing, str):
yield thing
elif not hasattr(thing, '__iter__'):
if thing is not None:
yield str(thing)
else:
for i in thing:
if isinstance(i, str):
yield i
elif not hasattr(i, '__iter__'):
if i is not None:
yield str(i)
elif i is not None:
for j in _flatten(i):
yield j
def parsestring(s, quoted=True):
'''parse a string using simple c-like syntax.
string must be in quotes if quoted is True.'''
if quoted:
if len(s) < 2 or s[0] != s[-1]:
raise SyntaxError(_('unmatched quotes'))
return s[1:-1].decode('string_escape')
return s.decode('string_escape')
class engine(object):
'''template expansion engine.
template expansion works like this. a map file contains key=value
pairs. if value is quoted, it is treated as string. otherwise, it
is treated as name of template file.
templater is asked to expand a key in map. it looks up key, and
looks for strings like this: {foo}. it expands {foo} by looking up
foo in map, and substituting it. expansion is recursive: it stops
when there is no more {foo} to replace.
expansion also allows formatting and filtering.
format uses key to expand each item in list. syntax is
{key%format}.
filter uses function to transform value. syntax is
{key|filter1|filter2|...}.'''
def __init__(self, loader, filters={}, defaults={}):
self._loader = loader
self._filters = filters
self._defaults = defaults
self._cache = {}
def process(self, t, mapping):
'''Perform expansion. t is name of map element to expand.
mapping contains added elements for use during expansion. Is a
generator.'''
return _flatten(self._process(self._load(t), mapping))
def _load(self, t):
'''load, parse, and cache a template'''
if t not in self._cache:
self._cache[t] = self._parse(self._loader(t))
return self._cache[t]
def _get(self, mapping, key):
v = mapping.get(key)
if v is None:
v = self._defaults.get(key, '')
if hasattr(v, '__call__'):
v = v(**mapping)
return v
def _filter(self, mapping, parts):
filters, val = parts
x = self._get(mapping, val)
for f in filters:
x = f(x)
return x
def _format(self, mapping, args):
key, parsed = args
v = self._get(mapping, key)
if not hasattr(v, '__iter__'):
raise SyntaxError(_("error expanding '%s%%%s'")
% (key, format))
lm = mapping.copy()
for i in v:
if isinstance(i, dict):
lm.update(i)
yield self._process(parsed, lm)
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 i
def _parse(self, tmpl):
'''preparse a template'''
parsed = []
pos, stop = 0, len(tmpl)
while pos < stop:
n = tmpl.find('{', pos)
if n < 0:
parsed.append((None, tmpl[pos:stop]))
break
if n > 0 and tmpl[n - 1] == '\\':
# escaped
parsed.append((None, tmpl[pos:n - 1] + "{"))
pos = n + 1
continue
if n > pos:
parsed.append((None, tmpl[pos:n]))
pos = n
n = tmpl.find('}', pos)
if n < 0:
# no closing
parsed.append((None, tmpl[pos:stop]))
break
expr = tmpl[pos + 1:n]
pos = n + 1
if '%' in expr:
key, t = expr.split('%')
parsed.append((self._format, (key.strip(),
self._load(t.strip()))))
elif '|' in expr:
parts = expr.split('|')
val = parts[0].strip()
try:
filters = [self._filters[f.strip()] for f in parts[1:]]
except KeyError, i:
raise SyntaxError(_("unknown filter '%s'") % i[0])
parsed.append((self._filter, (filters, val)))
else:
parsed.append((self._get, expr.strip()))
return parsed
def _process(self, parsed, mapping):
'''Render a template. Returns a generator.'''
for f, e in parsed:
if f:
yield f(mapping, e)
else:
yield e
engines = {'default': engine}
class templater(object):
def __init__(self, mapfile, filters={}, defaults={}, cache={},
minchunk=1024, maxchunk=65536):
'''set up template engine.
mapfile is name of file to read map definitions from.
filters is dict of functions. each transforms a value into another.
defaults is dict of default map definitions.'''
self.mapfile = mapfile or 'template'
self.cache = cache.copy()
self.map = {}
self.base = (mapfile and os.path.dirname(mapfile)) or ''
self.filters = templatefilters.filters.copy()
self.filters.update(filters)
self.defaults = defaults
self.minchunk, self.maxchunk = minchunk, maxchunk
self.engines = {}
if not mapfile:
return
if not os.path.exists(mapfile):
raise util.Abort(_('style not found: %s') % mapfile)
conf = config.config()
conf.read(mapfile)
for key, val in conf[''].items():
if val[0] in "'\"":
try:
self.cache[key] = parsestring(val)
except SyntaxError, inst:
raise SyntaxError('%s: %s' %
(conf.source('', key), inst.args[0]))
else:
val = 'default', val
if ':' in val[1]:
val = val[1].split(':', 1)
self.map[key] = val[0], os.path.join(self.base, val[1])
def __contains__(self, key):
return key in self.cache or key in self.map
def load(self, t):
'''Get the template for the given template name. Use a local cache.'''
if not t in self.cache:
try:
self.cache[t] = open(self.map[t][1]).read()
except IOError, inst:
raise IOError(inst.args[0], _('template file %s: %s') %
(self.map[t][1], inst.args[1]))
return self.cache[t]
def __call__(self, t, **mapping):
ttype = t in self.map and self.map[t][0] or 'default'
proc = self.engines.get(ttype)
if proc is None:
proc = engines[ttype](self.load, self.filters, self.defaults)
self.engines[ttype] = proc
stream = proc.process(t, mapping)
if self.minchunk:
stream = util.increasingchunks(stream, min=self.minchunk,
max=self.maxchunk)
return stream
def templatepath(name=None):
'''return location of template file or directory (if no name).
returns None if not found.'''
normpaths = []
# executable version (py2exe) doesn't support __file__
if hasattr(sys, 'frozen'):
module = sys.executable
else:
module = __file__
for f in path:
if f.startswith('/'):
p = f
else:
fl = f.split('/')
p = os.path.join(os.path.dirname(module), *fl)
if name:
p = os.path.join(p, name)
if name and os.path.exists(p):
return os.path.normpath(p)
elif os.path.isdir(p):
normpaths.append(os.path.normpath(p))
return normpaths
def stylemap(styles, paths=None):
"""Return path to mapfile for a given style.
Searches mapfile in the following locations:
1. templatepath/style/map
2. templatepath/map-style
3. templatepath/map
"""
if paths is None:
paths = templatepath()
elif isinstance(paths, str):
paths = [paths]
if isinstance(styles, str):
styles = [styles]
for style in styles:
if not style:
continue
locations = [os.path.join(style, 'map'), 'map-' + style]
locations.append('map')
for path in paths:
for location in locations:
mapfile = os.path.join(path, location)
if os.path.isfile(mapfile):
return style, mapfile
raise RuntimeError("No hgweb templates found in %r" % paths)