comparison mercurial/templatekw.py @ 36445:e8d37838f5df

templatekw: add 'requires' flag to switch to exception-safe interface

The current templatekw interface, f(repo, ctx, templ, **args), is horrible
because it's quite easy to encounter TypeError, ValueError, etc. It's also
bad for Python 3 porting due to the **kwargs issue.

This patch introduces a flag to switch to new f(context, mapping) API seen
in templater functions. The requirement spec isn't verified (yet) because
context.resource() can gracefully raise a ResourceUnavailable exception,
but it's planned to be used as a filter in the help, such as "Revision
Keywords" (if 'ctx' in requires), "File Keywords" (if 'fctx' in requires),
etc.

showauthor() is ported to the new API as an example. 20 more follows.

36444:717a279c0c21

    'extra': '{key}={value|stringescape}'
}
# filecopy is preserved for compatibility reasons
defaulttempl['filecopy'] = defaulttempl['file_copy']

# keywords are callables like:
# fn(repo, ctx, templ, cache, revcache, **args)
# with:
# repo - current repository instance
# ctx - the changectx being displayed
# templ - the templater instance
# cache - a cache dictionary for the whole templater run
# revcache - a cache dictionary for the current revision
keywords = {}

templatekeyword = registrar.templatekeyword(keywords)

@templatekeyword('author')
def showauthor(repo, ctx, templ, **args):
    """String. The unmodified author of the changeset."""
    return ctx.user()

@templatekeyword('bisect')
def showbisect(repo, ctx, templ, **args):
    """String. The changeset bisection status."""

36445:e8d37838f5df

    'extra': '{key}={value|stringescape}'
}
# filecopy is preserved for compatibility reasons
defaulttempl['filecopy'] = defaulttempl['file_copy']

# keywords are callables (see registrar.templatekeyword for details)
keywords = {}
templatekeyword = registrar.templatekeyword(keywords)

@templatekeyword('author', requires={'ctx'})
def showauthor(context, mapping):
    """String. The unmodified author of the changeset."""
    ctx = context.resource(mapping, 'ctx')
    return ctx.user()

@templatekeyword('bisect')
def showbisect(repo, ctx, templ, **args):
    """String. The changeset bisection status."""