# templater.py - template expansion for output # # Copyright 2005, 2006 Matt Mackall # # 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, parsed)) 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: # the keyword should be formatted with a template key, t = expr.split('%') parsed.append((self._format, (key.strip(), self._load(t.strip())))) elif '|' in expr: # process the keyword value with one or more filters 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: # just get the keyword 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)