view mercurial/templater.py @ 5197:55860a45bbf2

Enable demandimport only in scripts, not in importable modules (issue605)

This way other applications can choose if and when they want this feature,
because it might be problematic if those applications rely on ImportError.

# 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, incorporated herein by reference.

from i18n import _
from node import *
import cgi, re, sys, os, time, urllib, util, textwrap

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 templater(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\|%]+})))"
                             r"(\w+)(?:(?:%(\w+))|((?:\|\w+)*))[#}]")

    def __init__(self, mapfile, filters={}, defaults={}, cache={}):
        '''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 = filters
        self.defaults = defaults

        if not mapfile:
            return
        i = 0
        for l in file(mapfile):
            l = l.strip()
            i += 1
            if not l or l[0] in '#;': continue
            m = re.match(r'([a-zA-Z_][a-zA-Z0-9_]*)\s*=\s*(.+)$', l)
            if m:
                key, val = m.groups()
                if val[0] in "'\"":
                    try:
                        self.cache[key] = parsestring(val)
                    except SyntaxError, inst:
                        raise SyntaxError('%s:%s: %s' %
                                          (mapfile, i, inst.args[0]))
                else:
                    self.map[key] = os.path.join(self.base, val)
            else:
                raise SyntaxError(_("%s:%s: parse error") % (mapfile, i))

    def __contains__(self, key):
        return key in self.cache or key in self.map

    def __call__(self, t, **map):
        '''perform expansion.
        t is name of map element to expand.
        map is added elements to use during expansion.'''
        if not self.cache.has_key(t):
            try:
                self.cache[t] = file(self.map[t]).read()
            except IOError, inst:
                raise IOError(inst.args[0], _('template file %s: %s') %
                              (self.map[t], inst.args[1]))
        tmpl = self.cache[t]

        while tmpl:
            m = self.template_re.search(tmpl)
            if not m:
                yield tmpl
                break

            start, end = m.span(0)
            key, format, fl = m.groups()

            if start:
                yield tmpl[:start]
            tmpl = tmpl[end:]

            if key in map:
                v = map[key]
            else:
                v = self.defaults.get(key, "")
            if callable(v):
                v = v(**map)
            if format:
                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(format, **lm)
            else:
                if fl:
                    for f in fl.split("|")[1:]:
                        v = self.filters[f](v)
                yield v

agescales = [("second", 1),
             ("minute", 60),
             ("hour", 3600),
             ("day", 3600 * 24),
             ("week", 3600 * 24 * 7),
             ("month", 3600 * 24 * 30),
             ("year", 3600 * 24 * 365)]

agescales.reverse()

def age(date):
    '''turn a (timestamp, tzoff) tuple into an age string.'''

    def plural(t, c):
        if c == 1:
            return t
        return t + "s"
    def fmt(t, c):
        return "%d %s" % (c, plural(t, c))

    now = time.time()
    then = date[0]
    delta = max(1, int(now - then))

    for t, s in agescales:
        n = delta / s
        if n >= 2 or s == 1:
            return fmt(t, n)

def stringify(thing):
    '''turn nested template iterator into string.'''
    if hasattr(thing, '__iter__'):
        return "".join([stringify(t) for t in thing if t is not None])
    return str(thing)

para_re = None
space_re = None

def fill(text, width):
    '''fill many paragraphs.'''
    global para_re, space_re
    if para_re is None:
        para_re = re.compile('(\n\n|\n\\s*[-*]\\s*)', re.M)
        space_re = re.compile(r'  +')

    def findparas():
        start = 0
        while True:
            m = para_re.search(text, start)
            if not m:
                w = len(text)
                while w > start and text[w-1].isspace(): w -= 1
                yield text[start:w], text[w:]
                break
            yield text[start:m.start(0)], m.group(1)
            start = m.end(1)

    return "".join([space_re.sub(' ', textwrap.fill(para, width)) + rest
                    for para, rest in findparas()])

def firstline(text):
    '''return the first line of text'''
    try:
        return text.splitlines(1)[0].rstrip('\r\n')
    except IndexError:
        return ''

def isodate(date):
    '''turn a (timestamp, tzoff) tuple into an iso 8631 date and time.'''
    return util.datestr(date, format='%Y-%m-%d %H:%M')

def hgdate(date):
    '''turn a (timestamp, tzoff) tuple into an hg cset timestamp.'''
    return "%d %d" % date

def nl2br(text):
    '''replace raw newlines with xhtml line breaks.'''
    return text.replace('\n', '<br/>\n')

def obfuscate(text):
    text = unicode(text, util._encoding, 'replace')
    return ''.join(['&#%d;' % ord(c) for c in text])

def domain(author):
    '''get domain of author, or empty string if none.'''
    f = author.find('@')
    if f == -1: return ''
    author = author[f+1:]
    f = author.find('>')
    if f >= 0: author = author[:f]
    return author

def email(author):
    '''get email of author.'''
    r = author.find('>')
    if r == -1: r = None
    return author[author.find('<')+1:r]

def person(author):
    '''get name of author, or else username.'''
    f = author.find('<')
    if f == -1: return util.shortuser(author)
    return author[:f].rstrip()

def shortdate(date):
    '''turn (timestamp, tzoff) tuple into iso 8631 date.'''
    return util.datestr(date, format='%Y-%m-%d', timezone=False)

def indent(text, prefix):
    '''indent each non-empty line of text after first with prefix.'''
    lines = text.splitlines()
    num_lines = len(lines)
    def indenter():
        for i in xrange(num_lines):
            l = lines[i]
            if i and l.strip():
                yield prefix
            yield l
            if i < num_lines - 1 or text.endswith('\n'):
                yield '\n'
    return "".join(indenter())

def permissions(flags):
    if "l" in flags:
        return "lrwxrwxrwx"
    if "x" in flags:
        return "-rwxr-xr-x"
    return "-rw-r--r--"

common_filters = {
    "addbreaks": nl2br,
    "basename": os.path.basename,
    "age": age,
    "date": lambda x: util.datestr(x),
    "domain": domain,
    "email": email,
    "escape": lambda x: cgi.escape(x, True),
    "fill68": lambda x: fill(x, width=68),
    "fill76": lambda x: fill(x, width=76),
    "firstline": firstline,
    "tabindent": lambda x: indent(x, '\t'),
    "hgdate": hgdate,
    "isodate": isodate,
    "obfuscate": obfuscate,
    "permissions": permissions,
    "person": person,
    "rfc822date": lambda x: util.datestr(x, "%a, %d %b %Y %H:%M:%S"),
    "short": lambda x: x[:12],
    "shortdate": shortdate,
    "stringify": stringify,
    "strip": lambda x: x.strip(),
    "urlescape": lambda x: urllib.quote(x),
    "user": lambda x: util.shortuser(x),
    "stringescape": lambda x: x.encode('string_escape'),
    }

def templatepath(name=None):
    '''return location of template file or directory (if no name).
    returns None if not found.'''

    # executable version (py2exe) doesn't support __file__
    if hasattr(sys, 'frozen'):
        module = sys.executable
    else:
        module = __file__
    for f in 'templates', '../templates':
        fl = f.split('/')
        if name: fl.append(name)
        p = os.path.join(os.path.dirname(module), *fl)
        if (name and os.path.exists(p)) or os.path.isdir(p):
            return os.path.normpath(p)