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Diffstat (limited to 'doc/source')
| -rw-r--r-- | doc/source/devref/il8n.rst | 34 | ||||
| -rw-r--r-- | doc/source/devref/index.rst | 1 |
2 files changed, 35 insertions, 0 deletions
diff --git a/doc/source/devref/il8n.rst b/doc/source/devref/il8n.rst new file mode 100644 index 000000000..2264630be --- /dev/null +++ b/doc/source/devref/il8n.rst @@ -0,0 +1,34 @@ +Internationalization +==================== +nova uses `gettext <http://docs.python.org/library/gettext.html>`_ so that +user-facing strings such as log messages appear in the appropriate +language in different locales. + +To use gettext, make sure that the strings passed to the logger are wrapped +in a ``_()`` function call. For example:: + + LOG.debug(_("block_device_mapping %s"), block_device_mapping) + +If you have multiple arguments, the convention is to use named parameters. +It's common to use the ``locals()`` dict (which contains the names and values +of the local variables in the current scope) to do the string interpolation. +For example:: + + label = ... + sr_ref = ... + LOG.debug(_('Introduced %(label)s as %(sr_ref)s.') % locals()) + +If you do not follow the project conventions, your code may cause the +LocalizationTestCase.test_multiple_positional_format_placeholders test to fail +in nova/tests/test_localization.py. + +The ``_()`` function is brought into the global scope by doing:: + + import gettext + gettext.install("nova", unicode=1) + +In general, you shouldn't need to add these to any nova files, since the lines +are present in ``nova/__init__.py``. However, if this code is missing, it may +result in an error that looks like like:: + + NameError: name '_' is not defined diff --git a/doc/source/devref/index.rst b/doc/source/devref/index.rst index 6a22b0e74..be1188b78 100644 --- a/doc/source/devref/index.rst +++ b/doc/source/devref/index.rst @@ -36,6 +36,7 @@ Background Concepts for Nova :maxdepth: 3 threading + il8n distributed_scheduler multinic zone |