annotate mercurial/help/extensions.txt @ 22304:5678b0e3608f

templater: enable alias predicates to be used in "revset()" function

Before this patch, predicates defined in "[revsetalias]" can't be used
in the query specified to template function "revset()", because:

  - "revset()" uses "localrepository.revs()" to get query result, but
  - "localrepository.revs()" passes "None" as "ui" to "revset.match()", then
  - "revset.match()" can't recognize any alias predicates

To enable alias predicates to be used in "revset()" function, this
patch invokes "revset.match()" directly with "repo.ui".

This patch doesn't make "localrepository.revs()" pass "self.ui" to
"revset.match()", because this may be intentional implementation to
prevent alias predicates from shadowing built-in ones and breaking
functions internally using "localrepository.revs()".

Even if it isn't intentional one, the check for shadowing should be
implemented (maybe on default branch) before fixing it for safety.

Mercurial has the ability to add new features through the use of
extensions. Extensions may add new commands, add options to
existing commands, change the default behavior of commands, or
implement hooks.

To enable the "foo" extension, either shipped with Mercurial or in the
Python search path, create an entry for it in your configuration file,
like this::

  [extensions]
  foo =

You may also specify the full path to an extension::

  [extensions]
  myfeature = ~/.hgext/myfeature.py

See :hg:`help config` for more information on configuration files.

Extensions are not loaded by default for a variety of reasons:
they can increase startup overhead; they may be meant for advanced
usage only; they may provide potentially dangerous abilities (such
as letting you destroy or modify history); they might not be ready
for prime time; or they may alter some usual behaviors of stock
Mercurial. It is thus up to the user to activate extensions as
needed.

To explicitly disable an extension enabled in a configuration file of
broader scope, prepend its path with !::

  [extensions]
  # disabling extension bar residing in /path/to/extension/bar.py
  bar = !/path/to/extension/bar.py
  # ditto, but no path was supplied for extension baz
  baz = !