[PATCH RFC] HGPLAIN: allow exceptions to plain mode, like i18n, via HGPLAINEXCEPT

[Erik Zielke]

Den 04-01-2011 14:21, Brodie Rao skrev:
> # HG changeset patch
> # User Brodie Rao<brodie at bitheap.org>
> # Date 1294147116 -39600
> # Node ID b653ec8e753a01653d46c70c56e72a37f5906f58
> # Parent  f3058dd052819de75908599d93a29241ba69318f
> HGPLAIN: allow exceptions to plain mode, like i18n, via HGPLAINEXCEPT
>
> This makes it possible to gain the benefits of HGPLAIN for scripting
> while preserving different behaviors like internationalization.
I can definitiely see that people writing tools and scripts on top of 
Mercurial can use feature like this.

> diff --git a/mercurial/help/environment.txt b/mercurial/help/environment.txt
> --- a/mercurial/help/environment.txt
> +++ b/mercurial/help/environment.txt
> @@ -59,6 +59,14 @@ HGPLAIN
>       Equivalent options set via command line flags or environment
>       variables are not overridden.
>
> +HGPLAINEXCEPT
> +    This is a comma-separated list of features to preserve when
> +    HGPLAIN is enabled. Currently the only value supported is "i18n",
> +    which preserves internationalization in plain mode.
> +
> +    Setting HGPLAINEXCEPT to anything (even an empty string) will
> +    enable plain mode.
> +
Wouldn't it make sense to issue a warning, if an unsupported value is in 
HGPLAINEXCEPT? This would of course mean that there should be a way of 
specifying supported values.

>   HGUSER
>       This is the string used as the author of a commit. If not set,
>       available values will be considered in this order:
> diff --git a/mercurial/i18n.py b/mercurial/i18n.py
> --- a/mercurial/i18n.py
> +++ b/mercurial/i18n.py
> @@ -51,7 +51,13 @@ def gettext(message):
>           # An unknown encoding results in a LookupError.
>           return message
>
> -if 'HGPLAIN' in os.environ:
> +def _plain():
> +    if 'HGPLAIN' not in os.environ and 'HGPLAINEXCEPT' not in os.environ:
> +        return False
> +    exceptions = os.environ.get('HGPLAINEXCEPT', '').strip().split(',')
> +    return 'i18n' not in exceptions
> +
> +if _plain():
>       _ = lambda message: message
>   else:
>       _ = gettext
> diff --git a/mercurial/ui.py b/mercurial/ui.py
> --- a/mercurial/ui.py
> +++ b/mercurial/ui.py
> @@ -268,15 +268,22 @@ class ui(object):
>       def plain(self):
>           '''is plain mode active?
>
> -        Plain mode means that all configuration variables which affect the
> -        behavior and output of Mercurial should be ignored. Additionally, the
> -        output should be stable, reproducible and suitable for use in scripts or
> -        applications.
> +        Plain mode means that all configuration variables which affect
> +        the behavior and output of Mercurial should be
> +        ignored. Additionally, the output should be stable,
> +        reproducible and suitable for use in scripts or applications.
>
> -        The only way to trigger plain mode is by setting the `HGPLAIN'
> -        environment variable.
> +        The only way to trigger plain mode is by setting either the
> +        `HGPLAIN' or `HGPLAINEXCEPT' environment variables.
> +
> +        The return value can either be False, True, or a list of
> +        features that plain mode should not apply to (e.g., i18n,
> +        progress, etc).
>           '''
> -        return 'HGPLAIN' in os.environ
> +        if 'HGPLAIN' not in os.environ and 'HGPLAINEXCEPT' not in os.environ:
> +            return False
> +        exceptions = os.environ.get('HGPLAINEXCEPT', '').strip().split(',')
> +        return exceptions or True
>
>       def username(self):
>           """Return default username to be used in commits.
> diff --git a/tests/test-hgrc.t b/tests/test-hgrc.t
> --- a/tests/test-hgrc.t
> +++ b/tests/test-hgrc.t
> @@ -133,3 +133,39 @@ plain hgrc
>     none: ui.verbose=False
>     none: ui.debug=True
>     none: ui.quiet=False
> +
> +plain mode with exceptions
> +
> +  $ cat>  plain.py<<EOF
> +>  def uisetup(ui):
> +>      ui.write('plain: %r\n' % ui.plain())
> +>  EOF
> +  $ echo "[extensions]">>  $HGRCPATH
> +  $ echo "plain=./plain.py">>  $HGRCPATH
> +  $ HGPLAINEXCEPT=; export HGPLAINEXCEPT
> +  $ hg showconfig --config ui.traceback=True --debug
> +  plain: ['']
> +  read config from: $TESTTMP/hgrc
> +  $TESTTMP/hgrc:15: extensions.plain=./plain.py
> +  none: ui.traceback=True
> +  none: ui.verbose=False
> +  none: ui.debug=True
> +  none: ui.quiet=False
> +  $ unset HGPLAIN
> +  $ hg showconfig --config ui.traceback=True --debug
> +  plain: ['']
> +  read config from: $TESTTMP/hgrc
> +  $TESTTMP/hgrc:15: extensions.plain=./plain.py
> +  none: ui.traceback=True
> +  none: ui.verbose=False
> +  none: ui.debug=True
> +  none: ui.quiet=False
> +  $ HGPLAINEXCEPT=i18n; export HGPLAINEXCEPT
> +  $ hg showconfig --config ui.traceback=True --debug
> +  plain: ['i18n']
> +  read config from: $TESTTMP/hgrc
> +  $TESTTMP/hgrc:15: extensions.plain=./plain.py
> +  none: ui.traceback=True
> +  none: ui.verbose=False
> +  none: ui.debug=True
> +  none: ui.quiet=False
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-- 
Erik Zielke
aragost Trifork ag
http://aragost.com/mercurial/