templatefuncs: declare resource requirements for future use

mercurial/registrar.py

@@ -1,439 +1,444
 # registrar.py - utilities to register function for specific purpose
 #
 #  Copyright FUJIWARA Katsunori <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 from . import (
     configitems,
     error,
     pycompat,
     util,
 )
 
 # unlike the other registered items, config options are neither functions or
 # classes. Registering the option is just small function call.
 #
 # We still add the official API to the registrar module for consistency with
 # the other items extensions want might to register.
 configitem = configitems.getitemregister
 
 class _funcregistrarbase(object):
     """Base of decorator to register a function for specific purpose
 
     This decorator stores decorated functions into own dict 'table'.
 
     The least derived class can be defined by overriding 'formatdoc',
     for example::
 
         class keyword(_funcregistrarbase):
             _docformat = ":%s: %s"
 
     This should be used as below:
 
         keyword = registrar.keyword()
 
         @keyword('bar')
         def barfunc(*args, **kwargs):
             '''Explanation of bar keyword ....
             '''
             pass
 
     In this case:
 
     - 'barfunc' is stored as 'bar' in '_table' of an instance 'keyword' above
     - 'barfunc.__doc__' becomes ":bar: Explanation of bar keyword"
     """
     def __init__(self, table=None):
         if table is None:
             self._table = {}
         else:
             self._table = table
 
     def __call__(self, decl, *args, **kwargs):
         return lambda func: self._doregister(func, decl, *args, **kwargs)
 
     def _doregister(self, func, decl, *args, **kwargs):
         name = self._getname(decl)
 
         if name in self._table:
             msg = 'duplicate registration for name: "%s"' % name
             raise error.ProgrammingError(msg)
 
         if func.__doc__ and not util.safehasattr(func, '_origdoc'):
             doc = pycompat.sysbytes(func.__doc__).strip()
             func._origdoc = doc
             func.__doc__ = pycompat.sysstr(self._formatdoc(decl, doc))
 
         self._table[name] = func
         self._extrasetup(name, func, *args, **kwargs)
 
         return func
 
     def _parsefuncdecl(self, decl):
         """Parse function declaration and return the name of function in it
         """
         i = decl.find('(')
         if i >= 0:
             return decl[:i]
         else:
             return decl
 
     def _getname(self, decl):
         """Return the name of the registered function from decl
 
         Derived class should override this, if it allows more
         descriptive 'decl' string than just a name.
         """
         return decl
 
     _docformat = None
 
     def _formatdoc(self, decl, doc):
         """Return formatted document of the registered function for help
 
         'doc' is '__doc__.strip()' of the registered function.
         """
         return self._docformat % (decl, doc)
 
     def _extrasetup(self, name, func):
         """Execute exra setup for registered function, if needed
         """
 
 class command(_funcregistrarbase):
     """Decorator to register a command function to table
 
     This class receives a command table as its argument. The table should
     be a dict.
 
     The created object can be used as a decorator for adding commands to
     that command table. This accepts multiple arguments to define a command.
 
     The first argument is the command name (as bytes).
 
     The `options` keyword argument is an iterable of tuples defining command
     arguments. See ``mercurial.fancyopts.fancyopts()`` for the format of each
     tuple.
 
     The `synopsis` argument defines a short, one line summary of how to use the
     command. This shows up in the help output.
 
     There are three arguments that control what repository (if any) is found
     and passed to the decorated function: `norepo`, `optionalrepo`, and
     `inferrepo`.
 
     The `norepo` argument defines whether the command does not require a
     local repository. Most commands operate against a repository, thus the
     default is False. When True, no repository will be passed.
 
     The `optionalrepo` argument defines whether the command optionally requires
     a local repository. If no repository can be found, None will be passed
     to the decorated function.
 
     The `inferrepo` argument defines whether to try to find a repository from
     the command line arguments. If True, arguments will be examined for
     potential repository locations. See ``findrepo()``. If a repository is
     found, it will be used and passed to the decorated function.
 
     The `intents` argument defines a set of intended actions or capabilities
     the command is taking. These intents can be used to affect the construction
     of the repository object passed to the command. For example, commands
     declaring that they are read-only could receive a repository that doesn't
     have any methods allowing repository mutation. Other intents could be used
     to prevent the command from running if the requested intent could not be
     fulfilled.
 
     The following intents are defined:
 
     readonly
        The command is read-only
 
     The signature of the decorated function looks like this:
         def cmd(ui[, repo] [, <args>] [, <options>])
 
       `repo` is required if `norepo` is False.
       `<args>` are positional args (or `*args`) arguments, of non-option
       arguments from the command line.
       `<options>` are keyword arguments (or `**options`) of option arguments
       from the command line.
 
     See the WritingExtensions and MercurialApi documentation for more exhaustive
     descriptions and examples.
     """
 
     def _doregister(self, func, name, options=(), synopsis=None,
                     norepo=False, optionalrepo=False, inferrepo=False,
                     intents=None):
 
         func.norepo = norepo
         func.optionalrepo = optionalrepo
         func.inferrepo = inferrepo
         func.intents = intents or set()
         if synopsis:
             self._table[name] = func, list(options), synopsis
         else:
             self._table[name] = func, list(options)
         return func
 
 INTENT_READONLY = b'readonly'
 
 class revsetpredicate(_funcregistrarbase):
     """Decorator to register revset predicate
 
     Usage::
 
         revsetpredicate = registrar.revsetpredicate()
 
         @revsetpredicate('mypredicate(arg1, arg2[, arg3])')
         def mypredicatefunc(repo, subset, x):
             '''Explanation of this revset predicate ....
             '''
             pass
 
     The first string argument is used also in online help.
 
     Optional argument 'safe' indicates whether a predicate is safe for
     DoS attack (False by default).
 
     Optional argument 'takeorder' indicates whether a predicate function
     takes ordering policy as the last argument.
 
     Optional argument 'weight' indicates the estimated run-time cost, useful
     for static optimization, default is 1. Higher weight means more expensive.
     Usually, revsets that are fast and return only one revision has a weight of
     0.5 (ex. a symbol); revsets with O(changelog) complexity and read only the
     changelog have weight 10 (ex. author); revsets reading manifest deltas have
     weight 30 (ex. adds); revset reading manifest contents have weight 100
     (ex. contains). Note: those values are flexible. If the revset has a
     same big-O time complexity as 'contains', but with a smaller constant, it
     might have a weight of 90.
 
     'revsetpredicate' instance in example above can be used to
     decorate multiple functions.
 
     Decorated functions are registered automatically at loading
     extension, if an instance named as 'revsetpredicate' is used for
     decorating in extension.
 
     Otherwise, explicit 'revset.loadpredicate()' is needed.
     """
     _getname = _funcregistrarbase._parsefuncdecl
     _docformat = "``%s``\n    %s"
 
     def _extrasetup(self, name, func, safe=False, takeorder=False, weight=1):
         func._safe = safe
         func._takeorder = takeorder
         func._weight = weight
 
 class filesetpredicate(_funcregistrarbase):
     """Decorator to register fileset predicate
 
     Usage::
 
         filesetpredicate = registrar.filesetpredicate()
 
         @filesetpredicate('mypredicate()')
         def mypredicatefunc(mctx, x):
             '''Explanation of this fileset predicate ....
             '''
             pass
 
     The first string argument is used also in online help.
 
     Optional argument 'callstatus' indicates whether a predicate
      implies 'matchctx.status()' at runtime or not (False, by
      default).
 
     Optional argument 'callexisting' indicates whether a predicate
     implies 'matchctx.existing()' at runtime or not (False, by
     default).
 
     'filesetpredicate' instance in example above can be used to
     decorate multiple functions.
 
     Decorated functions are registered automatically at loading
     extension, if an instance named as 'filesetpredicate' is used for
     decorating in extension.
 
     Otherwise, explicit 'fileset.loadpredicate()' is needed.
     """
     _getname = _funcregistrarbase._parsefuncdecl
     _docformat = "``%s``\n    %s"
 
     def _extrasetup(self, name, func, callstatus=False, callexisting=False):
         func._callstatus = callstatus
         func._callexisting = callexisting
 
 class _templateregistrarbase(_funcregistrarbase):
     """Base of decorator to register functions as template specific one
     """
     _docformat = ":%s: %s"
 
 class templatekeyword(_templateregistrarbase):
     """Decorator to register template keyword
 
     Usage::
 
         templatekeyword = registrar.templatekeyword()
 
         # new API (since Mercurial 4.6)
         @templatekeyword('mykeyword', requires={'repo', 'ctx'})
         def mykeywordfunc(context, mapping):
             '''Explanation of this template keyword ....
             '''
             pass
 
         # old API
         @templatekeyword('mykeyword')
         def mykeywordfunc(repo, ctx, templ, cache, revcache, **args):
             '''Explanation of this template keyword ....
             '''
             pass
 
     The first string argument is used also in online help.
 
     Optional argument 'requires' should be a collection of resource names
     which the template keyword depends on. This also serves as a flag to
     switch to the new API. If 'requires' is unspecified, all template
     keywords and resources are expanded to the function arguments.
 
     'templatekeyword' instance in example above can be used to
     decorate multiple functions.
 
     Decorated functions are registered automatically at loading
     extension, if an instance named as 'templatekeyword' is used for
     decorating in extension.
 
     Otherwise, explicit 'templatekw.loadkeyword()' is needed.
     """
 
     def _extrasetup(self, name, func, requires=None):
         func._requires = requires
 
 class templatefilter(_templateregistrarbase):
     """Decorator to register template filer
 
     Usage::
 
         templatefilter = registrar.templatefilter()
 
         @templatefilter('myfilter', intype=bytes)
         def myfilterfunc(text):
             '''Explanation of this template filter ....
             '''
             pass
 
     The first string argument is used also in online help.
 
     Optional argument 'intype' defines the type of the input argument,
     which should be (bytes, int, templateutil.date, or None for any.)
 
     'templatefilter' instance in example above can be used to
     decorate multiple functions.
 
     Decorated functions are registered automatically at loading
     extension, if an instance named as 'templatefilter' is used for
     decorating in extension.
 
     Otherwise, explicit 'templatefilters.loadkeyword()' is needed.
     """
 
     def _extrasetup(self, name, func, intype=None):
         func._intype = intype
 
 class templatefunc(_templateregistrarbase):
     """Decorator to register template function
 
     Usage::
 
         templatefunc = registrar.templatefunc()
 
-        @templatefunc('myfunc(arg1, arg2[, arg3])', argspec='arg1 arg2 arg3')
+        @templatefunc('myfunc(arg1, arg2[, arg3])', argspec='arg1 arg2 arg3',
+                      requires={'ctx'})
         def myfuncfunc(context, mapping, args):
             '''Explanation of this template function ....
             '''
             pass
 
     The first string argument is used also in online help.
 
     If optional 'argspec' is defined, the function will receive 'args' as
     a dict of named arguments. Otherwise 'args' is a list of positional
     arguments.
 
+    Optional argument 'requires' should be a collection of resource names
+    which the template function depends on.
+
     'templatefunc' instance in example above can be used to
     decorate multiple functions.
 
     Decorated functions are registered automatically at loading
     extension, if an instance named as 'templatefunc' is used for
     decorating in extension.
 
     Otherwise, explicit 'templatefuncs.loadfunction()' is needed.
     """
     _getname = _funcregistrarbase._parsefuncdecl
 
-    def _extrasetup(self, name, func, argspec=None):
+    def _extrasetup(self, name, func, argspec=None, requires=()):
         func._argspec = argspec
+        func._requires = requires
 
 class internalmerge(_funcregistrarbase):
     """Decorator to register in-process merge tool
 
     Usage::
 
         internalmerge = registrar.internalmerge()
 
         @internalmerge('mymerge', internalmerge.mergeonly,
                        onfailure=None, precheck=None):
         def mymergefunc(repo, mynode, orig, fcd, fco, fca,
                         toolconf, files, labels=None):
             '''Explanation of this internal merge tool ....
             '''
             return 1, False # means "conflicted", "no deletion needed"
 
     The first string argument is used to compose actual merge tool name,
     ":name" and "internal:name" (the latter is historical one).
 
     The second argument is one of merge types below:
 
     ========== ======== ======== =========
     merge type precheck premerge fullmerge
     ========== ======== ======== =========
     nomerge     x        x        x
     mergeonly   o        x        o
     fullmerge   o        o        o
     ========== ======== ======== =========
 
     Optional argument 'onfailure' is the format of warning message
     to be used at failure of merging (target filename is specified
     at formatting). Or, None or so, if warning message should be
     suppressed.
 
     Optional argument 'precheck' is the function to be used
     before actual invocation of internal merge tool itself.
     It takes as same arguments as internal merge tool does, other than
     'files' and 'labels'. If it returns false value, merging is aborted
     immediately (and file is marked as "unresolved").
 
     'internalmerge' instance in example above can be used to
     decorate multiple functions.
 
     Decorated functions are registered automatically at loading
     extension, if an instance named as 'internalmerge' is used for
     decorating in extension.
 
     Otherwise, explicit 'filemerge.loadinternalmerge()' is needed.
     """
     _docformat = "``:%s``\n    %s"
 
     # merge type definitions:
     nomerge = None
     mergeonly = 'mergeonly'  # just the full merge, no premerge
     fullmerge = 'fullmerge'  # both premerge and merge
 
     def _extrasetup(self, name, func, mergetype,
                     onfailure=None, precheck=None):
         func.mergetype = mergetype
         func.onfailure = onfailure
         func.precheck = precheck

mercurial/templatefuncs.py

@@ -1,698 +1,698
 # templatefuncs.py - common template functions
 #
 # 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 or any later version.
 
 from __future__ import absolute_import
 
 import re
 
 from .i18n import _
 from .node import (
     bin,
     wdirid,
 )
 from . import (
     color,
     encoding,
     error,
     minirst,
     obsutil,
     registrar,
     revset as revsetmod,
     revsetlang,
     scmutil,
     templatefilters,
     templatekw,
     templateutil,
     util,
 )
 from .utils import (
     dateutil,
     stringutil,
 )
 
 evalrawexp = templateutil.evalrawexp
 evalwrapped = templateutil.evalwrapped
 evalfuncarg = templateutil.evalfuncarg
 evalboolean = templateutil.evalboolean
 evaldate = templateutil.evaldate
 evalinteger = templateutil.evalinteger
 evalstring = templateutil.evalstring
 evalstringliteral = templateutil.evalstringliteral
 
 # dict of template built-in functions
 funcs = {}
 templatefunc = registrar.templatefunc(funcs)
 
 @templatefunc('date(date[, fmt])')
 def date(context, mapping, args):
     """Format a date. See :hg:`help dates` for formatting
     strings. The default is a Unix date format, including the timezone:
     "Mon Sep 04 15:13:13 2006 0700"."""
     if not (1 <= len(args) <= 2):
         # i18n: "date" is a keyword
         raise error.ParseError(_("date expects one or two arguments"))
 
     date = evaldate(context, mapping, args[0],
                     # i18n: "date" is a keyword
                     _("date expects a date information"))
     fmt = None
     if len(args) == 2:
         fmt = evalstring(context, mapping, args[1])
     if fmt is None:
         return dateutil.datestr(date)
     else:
         return dateutil.datestr(date, fmt)
 
 @templatefunc('dict([[key=]value...])', argspec='*args **kwargs')
 def dict_(context, mapping, args):
     """Construct a dict from key-value pairs. A key may be omitted if
     a value expression can provide an unambiguous name."""
     data = util.sortdict()
 
     for v in args['args']:
         k = templateutil.findsymbolicname(v)
         if not k:
             raise error.ParseError(_('dict key cannot be inferred'))
         if k in data or k in args['kwargs']:
             raise error.ParseError(_("duplicated dict key '%s' inferred") % k)
         data[k] = evalfuncarg(context, mapping, v)
 
     data.update((k, evalfuncarg(context, mapping, v))
                 for k, v in args['kwargs'].iteritems())
     return templateutil.hybriddict(data)
 
-@templatefunc('diff([includepattern [, excludepattern]])')
+@templatefunc('diff([includepattern [, excludepattern]])', requires={'ctx'})
 def diff(context, mapping, args):
     """Show a diff, optionally
     specifying files to include or exclude."""
     if len(args) > 2:
         # i18n: "diff" is a keyword
         raise error.ParseError(_("diff expects zero, one, or two arguments"))
 
     def getpatterns(i):
         if i < len(args):
             s = evalstring(context, mapping, args[i]).strip()
             if s:
                 return [s]
         return []
 
     ctx = context.resource(mapping, 'ctx')
     chunks = ctx.diff(match=ctx.match([], getpatterns(0), getpatterns(1)))
 
     return ''.join(chunks)
 
-@templatefunc('extdata(source)', argspec='source')
+@templatefunc('extdata(source)', argspec='source', requires={'ctx', 'cache'})
 def extdata(context, mapping, args):
     """Show a text read from the specified extdata source. (EXPERIMENTAL)"""
     if 'source' not in args:
         # i18n: "extdata" is a keyword
         raise error.ParseError(_('extdata expects one argument'))
 
     source = evalstring(context, mapping, args['source'])
     if not source:
         sym = templateutil.findsymbolicname(args['source'])
         if sym:
             raise error.ParseError(_('empty data source specified'),
                                    hint=_("did you mean extdata('%s')?") % sym)
         else:
             raise error.ParseError(_('empty data source specified'))
     cache = context.resource(mapping, 'cache').setdefault('extdata', {})
     ctx = context.resource(mapping, 'ctx')
     if source in cache:
         data = cache[source]
     else:
         data = cache[source] = scmutil.extdatasource(ctx.repo(), source)
     return data.get(ctx.rev(), '')
 
-@templatefunc('files(pattern)')
+@templatefunc('files(pattern)', requires={'ctx'})
 def files(context, mapping, args):
     """All files of the current changeset matching the pattern. See
     :hg:`help patterns`."""
     if not len(args) == 1:
         # i18n: "files" is a keyword
         raise error.ParseError(_("files expects one argument"))
 
     raw = evalstring(context, mapping, args[0])
     ctx = context.resource(mapping, 'ctx')
     m = ctx.match([raw])
     files = list(ctx.matches(m))
     return templateutil.compatlist(context, mapping, "file", files)
 
 @templatefunc('fill(text[, width[, initialident[, hangindent]]])')
 def fill(context, mapping, args):
     """Fill many
     paragraphs with optional indentation. See the "fill" filter."""
     if not (1 <= len(args) <= 4):
         # i18n: "fill" is a keyword
         raise error.ParseError(_("fill expects one to four arguments"))
 
     text = evalstring(context, mapping, args[0])
     width = 76
     initindent = ''
     hangindent = ''
     if 2 <= len(args) <= 4:
         width = evalinteger(context, mapping, args[1],
                             # i18n: "fill" is a keyword
                             _("fill expects an integer width"))
         try:
             initindent = evalstring(context, mapping, args[2])
             hangindent = evalstring(context, mapping, args[3])
         except IndexError:
             pass
 
     return templatefilters.fill(text, width, initindent, hangindent)
 
-@templatefunc('formatnode(node)')
+@templatefunc('formatnode(node)', requires={'ui'})
 def formatnode(context, mapping, args):
     """Obtain the preferred form of a changeset hash. (DEPRECATED)"""
     if len(args) != 1:
         # i18n: "formatnode" is a keyword
         raise error.ParseError(_("formatnode expects one argument"))
 
     ui = context.resource(mapping, 'ui')
     node = evalstring(context, mapping, args[0])
     if ui.debugflag:
         return node
     return templatefilters.short(node)
 
-@templatefunc('mailmap(author)')
+@templatefunc('mailmap(author)', requires={'repo', 'cache'})
 def mailmap(context, mapping, args):
     """Return the author, updated according to the value
     set in the .mailmap file"""
     if len(args) != 1:
         raise error.ParseError(_("mailmap expects one argument"))
 
     author = evalstring(context, mapping, args[0])
 
     cache = context.resource(mapping, 'cache')
     repo = context.resource(mapping, 'repo')
 
     if 'mailmap' not in cache:
         data = repo.wvfs.tryread('.mailmap')
         cache['mailmap'] = stringutil.parsemailmap(data)
 
     return stringutil.mapname(cache['mailmap'], author)
 
 @templatefunc('pad(text, width[, fillchar=\' \'[, left=False]])',
               argspec='text width fillchar left')
 def pad(context, mapping, args):
     """Pad text with a
     fill character."""
     if 'text' not in args or 'width' not in args:
         # i18n: "pad" is a keyword
         raise error.ParseError(_("pad() expects two to four arguments"))
 
     width = evalinteger(context, mapping, args['width'],
                         # i18n: "pad" is a keyword
                         _("pad() expects an integer width"))
 
     text = evalstring(context, mapping, args['text'])
 
     left = False
     fillchar = ' '
     if 'fillchar' in args:
         fillchar = evalstring(context, mapping, args['fillchar'])
         if len(color.stripeffects(fillchar)) != 1:
             # i18n: "pad" is a keyword
             raise error.ParseError(_("pad() expects a single fill character"))
     if 'left' in args:
         left = evalboolean(context, mapping, args['left'])
 
     fillwidth = width - encoding.colwidth(color.stripeffects(text))
     if fillwidth <= 0:
         return text
     if left:
         return fillchar * fillwidth + text
     else:
         return text + fillchar * fillwidth
 
 @templatefunc('indent(text, indentchars[, firstline])')
 def indent(context, mapping, args):
     """Indents all non-empty lines
     with the characters given in the indentchars string. An optional
     third parameter will override the indent for the first line only
     if present."""
     if not (2 <= len(args) <= 3):
         # i18n: "indent" is a keyword
         raise error.ParseError(_("indent() expects two or three arguments"))
 
     text = evalstring(context, mapping, args[0])
     indent = evalstring(context, mapping, args[1])
 
     if len(args) == 3:
         firstline = evalstring(context, mapping, args[2])
     else:
         firstline = indent
 
     # the indent function doesn't indent the first line, so we do it here
     return templatefilters.indent(firstline + text, indent)
 
 @templatefunc('get(dict, key)')
 def get(context, mapping, args):
     """Get an attribute/key from an object. Some keywords
     are complex types. This function allows you to obtain the value of an
     attribute on these types."""
     if len(args) != 2:
         # i18n: "get" is a keyword
         raise error.ParseError(_("get() expects two arguments"))
 
     dictarg = evalwrapped(context, mapping, args[0])
     key = evalrawexp(context, mapping, args[1])
     try:
         return dictarg.getmember(context, mapping, key)
     except error.ParseError as err:
         # i18n: "get" is a keyword
         hint = _("get() expects a dict as first argument")
         raise error.ParseError(bytes(err), hint=hint)
 
 @templatefunc('if(expr, then[, else])')
 def if_(context, mapping, args):
     """Conditionally execute based on the result of
     an expression."""
     if not (2 <= len(args) <= 3):
         # i18n: "if" is a keyword
         raise error.ParseError(_("if expects two or three arguments"))
 
     test = evalboolean(context, mapping, args[0])
     if test:
         return evalrawexp(context, mapping, args[1])
     elif len(args) == 3:
         return evalrawexp(context, mapping, args[2])
 
 @templatefunc('ifcontains(needle, haystack, then[, else])')
 def ifcontains(context, mapping, args):
     """Conditionally execute based
     on whether the item "needle" is in "haystack"."""
     if not (3 <= len(args) <= 4):
         # i18n: "ifcontains" is a keyword
         raise error.ParseError(_("ifcontains expects three or four arguments"))
 
     haystack = evalwrapped(context, mapping, args[1])
     try:
         needle = evalrawexp(context, mapping, args[0])
         found = haystack.contains(context, mapping, needle)
     except error.ParseError:
         found = False
 
     if found:
         return evalrawexp(context, mapping, args[2])
     elif len(args) == 4:
         return evalrawexp(context, mapping, args[3])
 
 @templatefunc('ifeq(expr1, expr2, then[, else])')
 def ifeq(context, mapping, args):
     """Conditionally execute based on
     whether 2 items are equivalent."""
     if not (3 <= len(args) <= 4):
         # i18n: "ifeq" is a keyword
         raise error.ParseError(_("ifeq expects three or four arguments"))
 
     test = evalstring(context, mapping, args[0])
     match = evalstring(context, mapping, args[1])
     if test == match:
         return evalrawexp(context, mapping, args[2])
     elif len(args) == 4:
         return evalrawexp(context, mapping, args[3])
 
 @templatefunc('join(list, sep)')
 def join(context, mapping, args):
     """Join items in a list with a delimiter."""
     if not (1 <= len(args) <= 2):
         # i18n: "join" is a keyword
         raise error.ParseError(_("join expects one or two arguments"))
 
     joinset = evalwrapped(context, mapping, args[0])
     joiner = " "
     if len(args) > 1:
         joiner = evalstring(context, mapping, args[1])
     return joinset.join(context, mapping, joiner)
 
-@templatefunc('label(label, expr)')
+@templatefunc('label(label, expr)', requires={'ui'})
 def label(context, mapping, args):
     """Apply a label to generated content. Content with
     a label applied can result in additional post-processing, such as
     automatic colorization."""
     if len(args) != 2:
         # i18n: "label" is a keyword
         raise error.ParseError(_("label expects two arguments"))
 
     ui = context.resource(mapping, 'ui')
     thing = evalstring(context, mapping, args[1])
     # preserve unknown symbol as literal so effects like 'red', 'bold',
     # etc. don't need to be quoted
     label = evalstringliteral(context, mapping, args[0])
 
     return ui.label(thing, label)
 
 @templatefunc('latesttag([pattern])')
 def latesttag(context, mapping, args):
     """The global tags matching the given pattern on the
     most recent globally tagged ancestor of this changeset.
     If no such tags exist, the "{tag}" template resolves to
     the string "null". See :hg:`help revisions.patterns` for the pattern
     syntax.
     """
     if len(args) > 1:
         # i18n: "latesttag" is a keyword
         raise error.ParseError(_("latesttag expects at most one argument"))
 
     pattern = None
     if len(args) == 1:
         pattern = evalstring(context, mapping, args[0])
     return templatekw.showlatesttags(context, mapping, pattern)
 
 @templatefunc('localdate(date[, tz])')
 def localdate(context, mapping, args):
     """Converts a date to the specified timezone.
     The default is local date."""
     if not (1 <= len(args) <= 2):
         # i18n: "localdate" is a keyword
         raise error.ParseError(_("localdate expects one or two arguments"))
 
     date = evaldate(context, mapping, args[0],
                     # i18n: "localdate" is a keyword
                     _("localdate expects a date information"))
     if len(args) >= 2:
         tzoffset = None
         tz = evalfuncarg(context, mapping, args[1])
         if isinstance(tz, bytes):
             tzoffset, remainder = dateutil.parsetimezone(tz)
             if remainder:
                 tzoffset = None
         if tzoffset is None:
             try:
                 tzoffset = int(tz)
             except (TypeError, ValueError):
                 # i18n: "localdate" is a keyword
                 raise error.ParseError(_("localdate expects a timezone"))
     else:
         tzoffset = dateutil.makedate()[1]
     return templateutil.date((date[0], tzoffset))
 
 @templatefunc('max(iterable)')
 def max_(context, mapping, args, **kwargs):
     """Return the max of an iterable"""
     if len(args) != 1:
         # i18n: "max" is a keyword
         raise error.ParseError(_("max expects one argument"))
 
     iterable = evalwrapped(context, mapping, args[0])
     try:
         return iterable.getmax(context, mapping)
     except error.ParseError as err:
         # i18n: "max" is a keyword
         hint = _("max first argument should be an iterable")
         raise error.ParseError(bytes(err), hint=hint)
 
 @templatefunc('min(iterable)')
 def min_(context, mapping, args, **kwargs):
     """Return the min of an iterable"""
     if len(args) != 1:
         # i18n: "min" is a keyword
         raise error.ParseError(_("min expects one argument"))
 
     iterable = evalwrapped(context, mapping, args[0])
     try:
         return iterable.getmin(context, mapping)
     except error.ParseError as err:
         # i18n: "min" is a keyword
         hint = _("min first argument should be an iterable")
         raise error.ParseError(bytes(err), hint=hint)
 
 @templatefunc('mod(a, b)')
 def mod(context, mapping, args):
     """Calculate a mod b such that a / b + a mod b == a"""
     if not len(args) == 2:
         # i18n: "mod" is a keyword
         raise error.ParseError(_("mod expects two arguments"))
 
     func = lambda a, b: a % b
     return templateutil.runarithmetic(context, mapping,
                                       (func, args[0], args[1]))
 
 @templatefunc('obsfateoperations(markers)')
 def obsfateoperations(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfateoperations" is a keyword
         raise error.ParseError(_("obsfateoperations expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersoperations(markers)
         return templateutil.hybridlist(data, name='operation')
     except (TypeError, KeyError):
         # i18n: "obsfateoperations" is a keyword
         errmsg = _("obsfateoperations first argument should be an iterable")
         raise error.ParseError(errmsg)
 
 @templatefunc('obsfatedate(markers)')
 def obsfatedate(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfatedate" is a keyword
         raise error.ParseError(_("obsfatedate expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         # TODO: maybe this has to be a wrapped list of date wrappers?
         data = obsutil.markersdates(markers)
         return templateutil.hybridlist(data, name='date', fmt='%d %d')
     except (TypeError, KeyError):
         # i18n: "obsfatedate" is a keyword
         errmsg = _("obsfatedate first argument should be an iterable")
         raise error.ParseError(errmsg)
 
 @templatefunc('obsfateusers(markers)')
 def obsfateusers(context, mapping, args):
     """Compute obsfate related information based on markers (EXPERIMENTAL)"""
     if len(args) != 1:
         # i18n: "obsfateusers" is a keyword
         raise error.ParseError(_("obsfateusers expects one argument"))
 
     markers = evalfuncarg(context, mapping, args[0])
 
     try:
         data = obsutil.markersusers(markers)
         return templateutil.hybridlist(data, name='user')
     except (TypeError, KeyError, ValueError):
         # i18n: "obsfateusers" is a keyword
         msg = _("obsfateusers first argument should be an iterable of "
                 "obsmakers")
         raise error.ParseError(msg)
 
 @templatefunc('obsfateverb(successors, markers)')
 def obsfateverb(context, mapping, args):
     """Compute obsfate related information based on successors (EXPERIMENTAL)"""
     if len(args) != 2:
         # i18n: "obsfateverb" is a keyword
         raise error.ParseError(_("obsfateverb expects two arguments"))
 
     successors = evalfuncarg(context, mapping, args[0])
     markers = evalfuncarg(context, mapping, args[1])
 
     try:
         return obsutil.obsfateverb(successors, markers)
     except TypeError:
         # i18n: "obsfateverb" is a keyword
         errmsg = _("obsfateverb first argument should be countable")
         raise error.ParseError(errmsg)
 
-@templatefunc('relpath(path)')
+@templatefunc('relpath(path)', requires={'repo'})
 def relpath(context, mapping, args):
     """Convert a repository-absolute path into a filesystem path relative to
     the current working directory."""
     if len(args) != 1:
         # i18n: "relpath" is a keyword
         raise error.ParseError(_("relpath expects one argument"))
 
     repo = context.resource(mapping, 'repo')
     path = evalstring(context, mapping, args[0])
     return repo.pathto(path)
 
-@templatefunc('revset(query[, formatargs...])')
+@templatefunc('revset(query[, formatargs...])', requires={'repo', 'cache'})
 def revset(context, mapping, args):
     """Execute a revision set query. See
     :hg:`help revset`."""
     if not len(args) > 0:
         # i18n: "revset" is a keyword
         raise error.ParseError(_("revset expects one or more arguments"))
 
     raw = evalstring(context, mapping, args[0])
     repo = context.resource(mapping, 'repo')
 
     def query(expr):
         m = revsetmod.match(repo.ui, expr, lookup=revsetmod.lookupfn(repo))
         return m(repo)
 
     if len(args) > 1:
         formatargs = [evalfuncarg(context, mapping, a) for a in args[1:]]
         revs = query(revsetlang.formatspec(raw, *formatargs))
         revs = list(revs)
     else:
         cache = context.resource(mapping, 'cache')
         revsetcache = cache.setdefault("revsetcache", {})
         if raw in revsetcache:
             revs = revsetcache[raw]
         else:
             revs = query(raw)
             revs = list(revs)
             revsetcache[raw] = revs
     return templatekw.showrevslist(context, mapping, "revision", revs)
 
 @templatefunc('rstdoc(text, style)')
 def rstdoc(context, mapping, args):
     """Format reStructuredText."""
     if len(args) != 2:
         # i18n: "rstdoc" is a keyword
         raise error.ParseError(_("rstdoc expects two arguments"))
 
     text = evalstring(context, mapping, args[0])
     style = evalstring(context, mapping, args[1])
 
     return minirst.format(text, style=style, keep=['verbose'])[0]
 
 @templatefunc('separate(sep, args...)', argspec='sep *args')
 def separate(context, mapping, args):
     """Add a separator between non-empty arguments."""
     if 'sep' not in args:
         # i18n: "separate" is a keyword
         raise error.ParseError(_("separate expects at least one argument"))
 
     sep = evalstring(context, mapping, args['sep'])
     first = True
     for arg in args['args']:
         argstr = evalstring(context, mapping, arg)
         if not argstr:
             continue
         if first:
             first = False
         else:
             yield sep
         yield argstr
 
-@templatefunc('shortest(node, minlength=4)')
+@templatefunc('shortest(node, minlength=4)', requires={'repo'})
 def shortest(context, mapping, args):
     """Obtain the shortest representation of
     a node."""
     if not (1 <= len(args) <= 2):
         # i18n: "shortest" is a keyword
         raise error.ParseError(_("shortest() expects one or two arguments"))
 
     hexnode = evalstring(context, mapping, args[0])
 
     minlength = 4
     if len(args) > 1:
         minlength = evalinteger(context, mapping, args[1],
                                 # i18n: "shortest" is a keyword
                                 _("shortest() expects an integer minlength"))
 
     repo = context.resource(mapping, 'repo')
     if len(hexnode) > 40:
         return hexnode
     elif len(hexnode) == 40:
         try:
             node = bin(hexnode)
         except TypeError:
             return hexnode
     else:
         try:
             node = scmutil.resolvehexnodeidprefix(repo, hexnode)
         except error.WdirUnsupported:
             node = wdirid
         except error.LookupError:
             return hexnode
         if not node:
             return hexnode
     try:
         return scmutil.shortesthexnodeidprefix(repo, node, minlength)
     except error.RepoLookupError:
         return hexnode
 
 @templatefunc('strip(text[, chars])')
 def strip(context, mapping, args):
     """Strip characters from a string. By default,
     strips all leading and trailing whitespace."""
     if not (1 <= len(args) <= 2):
         # i18n: "strip" is a keyword
         raise error.ParseError(_("strip expects one or two arguments"))
 
     text = evalstring(context, mapping, args[0])
     if len(args) == 2:
         chars = evalstring(context, mapping, args[1])
         return text.strip(chars)
     return text.strip()
 
 @templatefunc('sub(pattern, replacement, expression)')
 def sub(context, mapping, args):
     """Perform text substitution
     using regular expressions."""
     if len(args) != 3:
         # i18n: "sub" is a keyword
         raise error.ParseError(_("sub expects three arguments"))
 
     pat = evalstring(context, mapping, args[0])
     rpl = evalstring(context, mapping, args[1])
     src = evalstring(context, mapping, args[2])
     try:
         patre = re.compile(pat)
     except re.error:
         # i18n: "sub" is a keyword
         raise error.ParseError(_("sub got an invalid pattern: %s") % pat)
     try:
         yield patre.sub(rpl, src)
     except re.error:
         # i18n: "sub" is a keyword
         raise error.ParseError(_("sub got an invalid replacement: %s") % rpl)
 
 @templatefunc('startswith(pattern, text)')
 def startswith(context, mapping, args):
     """Returns the value from the "text" argument
     if it begins with the content from the "pattern" argument."""
     if len(args) != 2:
         # i18n: "startswith" is a keyword
         raise error.ParseError(_("startswith expects two arguments"))
 
     patn = evalstring(context, mapping, args[0])
     text = evalstring(context, mapping, args[1])
     if text.startswith(patn):
         return text
     return ''
 
 @templatefunc('word(number, text[, separator])')
 def word(context, mapping, args):
     """Return the nth word from a string."""
     if not (2 <= len(args) <= 3):
         # i18n: "word" is a keyword
         raise error.ParseError(_("word expects two or three arguments, got %d")
                                % len(args))
 
     num = evalinteger(context, mapping, args[0],
                       # i18n: "word" is a keyword
                       _("word expects an integer index"))
     text = evalstring(context, mapping, args[1])
     if len(args) == 3:
         splitter = evalstring(context, mapping, args[2])
     else:
         splitter = None
 
     tokens = text.split(splitter)
     if num >= len(tokens) or num < -len(tokens):
         return ''
     else:
         return tokens[num]
 
 def loadfunction(ui, extname, registrarobj):
     """Load template function from specified registrarobj
     """
     for name, func in registrarobj._table.iteritems():
         funcs[name] = func
 
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = funcs.values()