view mercurial/templater.py @ 9469:7f0f882af23d

config: abort on indented non-continuation lines (issue1829)

Previously, as soon as a continuation would be met, "cont" would stay
forever set to True, but "item" was set back to "None".
This caused the continuation code bits to run every time, until the next
"self.get(section, item) + '\n'" which would crash.

# templater.py - template expansion for output
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# 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)