ref: d68f4adeba6ef0db7590cf7c4e1518f4d4bdedff
dir: /sys/lib/python/mercurial/templater.py/
# 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, incorporated herein by reference.
from i18n import _
import re, sys, os
import util, config, templatefilters
path = ['templates', '../templates']
stringify = templatefilters.stringify
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|...}.'''
template_re = re.compile(r'{([\w\|%]+)}|#([\w\|%]+)#')
def __init__(self, loader, filters={}, defaults={}):
self.loader = loader
self.filters = filters
self.defaults = defaults
self.cache = {}
def process(self, t, map):
'''Perform expansion. t is name of map element to expand. map contains
added elements for use during expansion. Is a generator.'''
tmpl = self.loader(t)
iters = [self._process(tmpl, map)]
while iters:
try:
item = iters[0].next()
except StopIteration:
iters.pop(0)
continue
if isinstance(item, str):
yield item
elif item is None:
yield ''
elif hasattr(item, '__iter__'):
iters.insert(0, iter(item))
else:
yield str(item)
def _format(self, expr, get, map):
key, format = expr.split('%')
v = get(key)
if not hasattr(v, '__iter__'):
raise SyntaxError(_("error expanding '%s%%%s'") % (key, format))
lm = map.copy()
for i in v:
lm.update(i)
yield self.process(format, lm)
def _filter(self, expr, get, map):
if expr not in self.cache:
parts = expr.split('|')
val = parts[0]
try:
filters = [self.filters[f] for f in parts[1:]]
except KeyError, i:
raise SyntaxError(_("unknown filter '%s'") % i[0])
def apply(get):
x = get(val)
for f in filters:
x = f(x)
return x
self.cache[expr] = apply
return self.cache[expr](get)
def _process(self, tmpl, map):
'''Render a template. Returns a generator.'''
def get(key):
v = map.get(key)
if v is None:
v = self.defaults.get(key, '')
if hasattr(v, '__call__'):
v = v(**map)
return v
while tmpl:
m = self.template_re.search(tmpl)
if not m:
yield tmpl
break
start, end = m.span(0)
variants = m.groups()
expr = variants[0] or variants[1]
if start:
yield tmpl[:start]
tmpl = tmpl[end:]
if '%' in expr:
yield self._format(expr, get, map)
elif '|' in expr:
yield self._filter(expr, get, map)
else:
yield get(expr)
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, **map):
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, map)
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(style, 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]
locations = style and [os.path.join(style, "map"), "map-" + style] or []
locations.append("map")
for path in paths:
for location in locations:
mapfile = os.path.join(path, location)
if os.path.isfile(mapfile):
return mapfile
raise RuntimeError("No hgweb templates found in %r" % paths)