SYNOPSIS

 Used internally by Log::Report

DESCRIPTION

Any used of a translation function, like Log::Report::__() or Log::Report::__x() will result in this object. It will capture some environmental information, and delay the translation until it is needed.

Creating an object first, and translating it later, is slower than translating it immediately. However, on the location where the message is produced, we do not yet know to what language to translate: that depends on the front-end, the log dispatcher.

See DETAILS section below, for an in-depth description.

DETAILS

OPTIONS and VARIABLES

The Log::Report functions which define translation request can all have OPTIONS. Some can have VARIABLES to be interpolated in the string as well. To distinguish between the OPTIONS and VARIABLES (both a list of key-value pairs), the keys of the OPTIONS start with an underscore _. As result of this, please avoid the use of keys which start with an underscore in variable names. On the other hand, you are allowed to interpolate OPTION values in your strings.

Interpolating

With the __x() or __nx(), interpolation will take place on the translated MSGID string. The translation can contain the VARIABLE and OPTION names inbetween curly brackets. Text between curly brackets which is not a known parameter will be left untouched.

Next to the name, you can specify a format code. With gettext(), you often see this:

 printf gettext("approx pi: %.6f\n"), PI;

Locale::TextDomain has two ways.

 printf __"approx pi: %.6f\n", PI;
 print __x"approx pi: {approx}\n", approx => sprintf("%.6f", PI);

The first does not respect the wish to be able to reorder the arguments during translation. The second version is quite long. With Log::Report, above syntaxes do work, but you can also do

 print __x"approx pi: {pi%.6f}\n", pi => PI;

So: the interpolation syntax is { name [format] } . Other examples:

 print __x "{perms} {links%2d} {user%-8s} {size%10d} {fn}\n"
         , perms => '-rw-r--r--', links => 1, user => 'me'
         , size => '12345', fn => $filename;

An additional advantage is the fact that not all languages produce comparible length strings. Now, the translators can take care that the layout of tables is optimal.

Interpolation of OPTIONS

You are permitted the interpolate OPTION values in your string. This may simplify your coding. The useful names are:

» Example: using the _count

With Locale::TextDomain, you have to do

  use Locale::TextDomain;
  print __nx ( "One file has been deleted.\n"
             , "{num} files have been deleted.\n"
             , $num_files
             , num => $num_files
             );

With Log::Report, you can do

  use Log::Report;
  print __nx ( "One file has been deleted.\n"
             , "{_count} files have been deleted.\n"
             , $num_files
             );

Of course, you need to be aware that the name used to reference the counter is pixed to _count. The first example works as well, but is more verbose.

Interpolation of VARIABLES

There is no way of checking beforehand whether you have provided all required values, to be interpolated in the translated string. A translation could be specified like this:

 my @files = @ARGV;
 local $"  = ', ';
 my $s = __nx "One file specified ({files})"
            , "{_count} files specified ({files})"
            , scalar @files     # actually, 'scalar' is not needed
            , files => \@files;

For interpolating, the following rules apply:

» Example: reducing the number of translations

This way of translating is somewhat expensive, because an object to handle the __x() is created each time.

 for my $i (1..100_000)
 {   print __x "Hello World {i}\n", $i;
 }

The suggestion that Locale::TextDomain makes to improve performance, is to get the translation outside the loop, which only works without interpolation:

 use Locale::TextDomain;
 my $i = 42;
 my $s = __x("Hello World {i}\n", i => $i);
 foreach $i (1..100_000)
 {   print $s;
 }

Oops, not what you mean. With Log::Report, you can do

 use Log::Report;
 my $i;
 my $s = __x("Hello World {i}", i => \$i);
 foreach $i (1..100_000)
 {   print $s;
 }

Mind you not to write: for my $i in this case!!!! You can also write an incomplete translation:

 use Log::Report;
 my $s = __x "Hello World {i}";
 foreach my $i (1..100_000)
 {   print $s->(i => $i);
 }

In either case, the translation will be looked-up only once.