Merges PO/POT files with PO files.

This task is used when messages in the source code change: when they do, mix gettext.extract is usually used to extract the new messages to POT files. At this point, developers or translators can use this task to "sync" the newly-updated POT files with the existing locale-specific PO files. All the metadata for each message (like position in the source code, comments, and so on) is taken from the newly-updated POT file; the only things taken from the PO file are the actual translated strings.

Fuzzy Matching

Messages in the updated PO/POT file that have an exact match (a message with the same msgid) in the old PO file are merged as described above. When a message in the updated PO/POT files has no match in the old PO file, Gettext attemps a fuzzy match for that message. For example, imagine we have this POT file:

msgid "hello, world!"
msgstr ""

and we merge it with this PO file:

# No exclamation point here in the msgid
msgid "hello, world"
msgstr "ciao, mondo"

Since the two messages are similar, Gettext takes the msgstr from the existing message over to the new message, which it however marks as fuzzy:

#, fuzzy
msgid "hello, world!"
msgstr "ciao, mondo"

Generally, a fuzzy flag calls for review from a translator.

Fuzzy matching can be configured (for example, the threshold for message similarity can be tweaked) or disabled entirely. Look at the "Options" section.

Usage

mix gettext.merge OLD_FILE UPDATED_FILE [OPTIONS]
mix gettext.merge DIR [OPTIONS]

If two files are given as arguments, OLD_FILE must be a .po file and UPDATE_FILE must be a .po/.pot file. The first one is the old PO file, while the second one is the last generated one. They are merged and written over the first file. For example:

mix gettext.merge priv/gettext/en/LC_MESSAGES/default.po priv/gettext/default.pot

If only one argument is given, then that argument must be a directory containing Gettext messages (with .pot files at the root level alongside locale directories - this is usually a "backend" directory used by a Gettext backend, see Gettext.Backend). For example:

mix gettext.merge priv/gettext

If the --locale LOCALE option is given, then only the PO files in <DIR>/<LOCALE>/LC_MESSAGES will be merged with the POT files in DIR. If no options are given, then all the PO files for all locales under DIR are merged with the POT files in DIR.

Plural Forms

By default, Gettext will determine the number of plural forms for newly-generated messages by checking the value of nplurals in the Plural-Forms header in the existing .po file. If a .po file doesn't already exist and Gettext is creating a new one or if the Plural-Forms header is not in the .po file, Gettext will use the number of plural forms that the plural module (see Gettext.Plural) returns for the locale of the file being created. The content of the Plural-Forms header can be forced through the --plural-forms-header option (see below).

Options

• --locale - a string representing a locale. If this is provided, then only the PO files in <DIR>/<LOCALE>/LC_MESSAGES will be merged with the POT files in DIR. This option can only be given when a single argument is passed to the task (a directory).

• --no-fuzzy - don't perform fuzzy matching when merging files.

• --fuzzy-threshold - a float between 0 and 1 which represents the minimum Jaro distance needed for two messages to be considered a fuzzy match. Overrides the global :fuzzy_threshold option (see the docs for Gettext for more information on this option).

• --plural-forms - (deprecated in v0.22.0) an integer strictly greater than 0. If this is passed, new messages in the target PO files will have this number of empty plural forms. This is deprecated in favor of passing the --plural-forms-header, which contains the whole plural-forms specification. See the "Plural forms" section above.

• --plural-forms-header - the content of the Plural-Forms header as a string. If this is passed, new messages in the target PO files will use this content to determine the number of plurals. See the "Plural Forms" section.

• --on-obsolete - controls what happens when obsolete messages are found. If mark_as_obsolete, messages are kept and marked as obsolete. If delete, obsolete messages are deleted. Defaults to delete.

• --store-previous-message-on-fuzzy-match - controls if the previous messages are recorded on fuzzy matches. Is off by default.