view mercurial/help.py @ 13950:14d0553bd48b

help: do not show full help text for command on option errors

Example

  $ hg clone --jump foo bar
  hg clone: option --jump not recognized
  hg clone [OPTION]... SOURCE [DEST]

  make a copy of an existing repository

  options:

   -U --noupdate           the clone will include an empty working copy (only a
                           repository)
   -u --updaterev REV      revision, tag or branch to check out
   -r --rev REV [+]        include the specified changeset
   -b --branch BRANCH [+]  clone only the specified branch
      --pull               use pull protocol to copy metadata
      --uncompressed       use uncompressed transfer (fast over LAN)
   -e --ssh CMD            specify ssh command to use
      --remotecmd CMD      specify hg command to run on the remote side
      --insecure           do not verify server certificate (ignoring
                           web.cacerts config)

  [+] marked option can be specified multiple times

  use "hg help clone" to show the full help text

Motivation for this change

  If the user already has specified the command, he probably already knows
  the command to some extent. Apparently, he has a problem with the options,
  so we show him just the synopsis with the short help and the details about
  the options, with a hint on the last line how to get the full help text.

Why is Mercurial better with this change?

  Experts who just forgot about the details of an option don't get that
  much text thrown at them, while the newbies still get a hint on the last
  line how to get the full help text.

# help.py - help data for mercurial
#
# Copyright 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 i18n import gettext, _
import sys, os
import extensions


def moduledoc(file):
    '''return the top-level python documentation for the given file

    Loosely inspired by pydoc.source_synopsis(), but rewritten to
    handle triple quotes and to return the whole text instead of just
    the synopsis'''
    result = []

    line = file.readline()
    while line[:1] == '#' or not line.strip():
        line = file.readline()
        if not line:
            break

    start = line[:3]
    if start == '"""' or start == "'''":
        line = line[3:]
        while line:
            if line.rstrip().endswith(start):
                line = line.split(start)[0]
                if line:
                    result.append(line)
                break
            elif not line:
                return None # unmatched delimiter
            result.append(line)
            line = file.readline()
    else:
        return None

    return ''.join(result)

def listexts(header, exts, maxlength, indent=1):
    '''return a text listing of the given extensions'''
    if not exts:
        return ''
    result = '\n%s\n\n' % header
    for name, desc in sorted(exts.iteritems()):
        result += '%s%-*s %s\n' % (' ' * indent, maxlength + 2,
                                   ':%s:' % name, desc)
    return result

def extshelp():
    doc = loaddoc('extensions')()

    exts, maxlength = extensions.enabled()
    doc += listexts(_('enabled extensions:'), exts, maxlength)

    exts, maxlength = extensions.disabled()
    doc += listexts(_('disabled extensions:'), exts, maxlength)

    return doc

def loaddoc(topic):
    """Return a delayed loader for help/topic.txt."""

    def loader():
        if hasattr(sys, 'frozen'):
            module = sys.executable
        else:
            module = __file__
        base = os.path.dirname(module)

        for dir in ('.', '..'):
            docdir = os.path.join(base, dir, 'help')
            if os.path.isdir(docdir):
                break

        path = os.path.join(docdir, topic + ".txt")
        doc = gettext(open(path).read())
        for rewriter in helphooks.get(topic, []):
            doc = rewriter(topic, doc)
        return doc

    return loader

helptable = sorted([
    (["config", "hgrc"], _("Configuration Files"), loaddoc('config')),
    (["dates"], _("Date Formats"), loaddoc('dates')),
    (["patterns"], _("File Name Patterns"), loaddoc('patterns')),
    (['environment', 'env'], _('Environment Variables'),
     loaddoc('environment')),
    (['revs', 'revisions'], _('Specifying Single Revisions'),
     loaddoc('revisions')),
    (['mrevs', 'multirevs'], _('Specifying Multiple Revisions'),
     loaddoc('multirevs')),
    (['revset', 'revsets'], _("Specifying Revision Sets"), loaddoc('revsets')),
    (['diffs'], _('Diff Formats'), loaddoc('diffs')),
    (['merge-tools'], _('Merge Tools'), loaddoc('merge-tools')),
    (['templating', 'templates'], _('Template Usage'),
     loaddoc('templates')),
    (['urls'], _('URL Paths'), loaddoc('urls')),
    (["extensions"], _("Using additional features"), extshelp),
    (["subrepo", "subrepos"], _("Subrepositories"), loaddoc('subrepos')),
    (["hgweb"], _("Configuring hgweb"), loaddoc('hgweb')),
    (["glossary"], _("Glossary"), loaddoc('glossary')),
])

# Map topics to lists of callable taking the current topic help and
# returning the updated version
helphooks = {
}

def addtopichook(topic, rewriter):
    helphooks.setdefault(topic, []).append(rewriter)

def makeitemsdoc(topic, doc, marker, items):
    """Extract docstring from the items key to function mapping, build a
    .single documentation block and use it to overwrite the marker in doc
    """
    entries = []
    for name in sorted(items):
        text = (items[name].__doc__ or '').rstrip()
        if not text:
            continue
        text = gettext(text)
        lines = text.splitlines()
        lines[1:] = [('  ' + l.strip()) for l in lines[1:]]
        entries.append('\n'.join(lines))
    entries = '\n\n'.join(entries)
    return doc.replace(marker, entries)