Perl::Critic::Policy::Miscellanea::TextDomainPlaceholders - check placeholder names in Locale::TextDomain calls
This policy is part of the Perl::Critic::Pulp addon. It checks the placeholder arguments in format strings to the following functions from Locale::TextDomain.
Perl::Critic::Pulp
Locale::TextDomain
__x __nx __xn __px __npx
Calls with a key missing from the args or args unused by the format are reported.
print __x('Searching for {data}', # bad datum => 123); print __nx('Read one file', 'Read {num} files', # bad $n, count => 123);
This is normally a mistake, so this policy is under the bugs theme (see "POLICY THEMES" in Perl::Critic). An error can easily go unnoticed because (as of Locale::TextDomain version 1.16) a placeholder without a corresponding arg goes through unexpanded and any extra args are ignored.
bugs
The way Locale::TextDomain parses the format string allows anything between { } as a key, but for the purposes of this policy only symbols (alphanumeric plus "_") are taken to be a key. This is almost certainly what you'll want to use, and it's then possible to include literal braces in a format string without tickling this policy all the time. (Symbol characters are per Perl \w, so non-ASCII is supported, though the Gettext manual in node "Charset conversion" recommends message-IDs should be ASCII-only.)
{ }
\w
If the format string is not a literal then it might use any args, so all are considered used.
# ok, 'datum' might be used __x($my_format, datum => 123);
Literal portions of the format are still checked.
# bad, 'foo' not present in args __x("{foo} $bar", datum => 123);
Conversely if the args have some non-literals then they could be anything, so everything in the format string is considered present.
# ok, $something might be 'world' __x('hello {world}', $something => 123);
But again if some args are literals they can be checked.
# bad, 'blah' is not used __x('hello {world}', $something => 123, blah => 456);
If there's non-literals both in the format and in the args then nothing is checked, since it could all match up fine at runtime.
__nx
A missing count argument to __nx, __xn and __npx is sometimes noticed by this policy. For example,
__xn
__npx
print __nx('Read one file', 'Read {numfiles} files', numfiles => $numfiles); # bad
If the count argument looks like a key then it's reported as a probable mistake. This is not the main aim of this policy but it's done because otherwise no violations would be reported at all. (The next argument would be the key, and normally being an expression it would be assumed to fulfil the format strings at runtime.)
Perl::Critic::Pulp, Perl::Critic, Locale::TextDomain, Perl::Critic::Policy::Miscellanea::TextDomainUnused
http://user42.tuxfamily.org/perl-critic-pulp/index.html
Copyright 2008, 2009, 2010, 2011 Kevin Ryde
Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
Perl-Critic-Pulp is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Perl-Critic-Pulp. If not, see <http://www.gnu.org/licenses/>.
To install Perl::Critic::Pulp, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Perl::Critic::Pulp
CPAN shell
perl -MCPAN -e shell install Perl::Critic::Pulp
For more information on module installation, please visit the detailed CPAN module installation guide.