1Log::Report::Message(3)User Contributed Perl DocumentatioLnog::Report::Message(3)
2
6 Log::Report::Message - a piece of text to be translated
7
9 Log::Report::Message is extended by
10 Dancer2::Plugin::LogReport::Message
11
13 # Objects created by Log::Report's __ functions
14 # Full feature description in the DETAILS section
15 # no interpolation
17 __"Hello, World";
18 # with interpolation
20 __x"age {years}", years => 12;
21 # interpolation for one or many
23 my $nr_files = @files;
24 __nx"one file", "{_count} files", $nr_files;
25 __nx"one file", "{_count} files", \@files;
26 # interpolation of arrays
28 __x"price-list: {prices%.2f}", prices => \@prices, _join => ', ';
29 # white-spacing on msgid preserved
31 print __"\tCongratulations,\n";
32 print "\t", __("Congratulations,"), "\n"; # same
33
35 Any use of a translation function exported by Log::Report, like "__()"
36 (the function is named underscore-underscore) or "__x()" (underscore-
37 underscore-x) will result in this object. It will capture some
38 environmental information, and delay the translation until it is
39 needed.
40 Creating an object first and translating it later, is slower than
42 translating it immediately. However, on the location where the message
43 is produced, we do not yet know in what language to translate it to:
44 that depends on the front-end, the log dispatcher.
45
47 Constructors
48 $obj->clone(%options, $variables)
49 Returns a new object which copies info from original, and updates
50 it with the specified %options and $variables. The advantage is
51 that the cached translations are shared between the objects.
52 example: use of clone()
54 my $s = __x "found {nr} files", nr => 5;
56 my $t = $s->clone(nr => 3);
57 my $t = $s->(nr => 3); # equivalent
58 print $s; # found 5 files
59 print $t; # found 3 files
60 Log::Report::Message->fromTemplateToolkit($domain, $msgid, $params)
62 See Log::Report::Extract::Template on the details how to integrate
63 Log::Report translations with Template::Toolkit (version 1 and 2)
64 Log::Report::Message->new(%options)
66 End-users: do not use this method directly, but use
67 Log::Report::__() and friends. The %options is a mixed list of
68 object initiation parameters (all with a leading underscore) and
69 variables to be filled in into the translated "_msgid" string.
70 -Option --Default
72 _append undef
73 _category undef
74 _class []
75 _classes []
76 _context undef
77 _count undef
78 _domain <from "use Log::Report">
79 _expand false
80 _join $" $LIST_SEPARATOR
81 _lang <from locale>
82 _msgctxt undef
83 _msgid undef
84 _plural undef
85 _prepend undef
86 _to <undef>
87 _append => STRING|MESSAGE
89 Text as STRING or MESSAGE object to be displayed after the
90 display of this message.
91 _category => INTEGER
93 The category when the real gettext library is used, for instance
94 LC_MESSAGES.
95 _class => STRING|ARRAY
97 When messages are used for exception based programming, you add
98 "_class" parameters to the argument list. Later, with for
99 instance Log::Report::Dispatcher::Try::wasFatal(class), you can
100 check the category of the message.
101 One message can be part of multiple classes. The STRING is used
103 as comma- and/or blank separated list of class tokens
104 (barewords), the ARRAY lists all tokens separately. See
105 classes().
106 _classes => STRING|ARRAY
108 Alternative for "_class", which cannot be used at the same time.
109 _context => WORDS|ARRAY
111 [1.00] Set keywords which can be used to select alternatives
112 between translations. Read the DETAILS section in
113 Log::Report::Translator::Context
114 _count => INTEGER|ARRAY|HASH
116 When defined, the "_plural" need to be defined as well. When an
117 ARRAY is provided, the length of the ARRAY is taken. When a HASH
118 is given, the number of keys in the HASH is used.
119 _domain => STRING
121 The text-domain (translation table) to which this "_msgid"
122 belongs.
123 With this parameter, your can "borrow" translations from other
125 textdomains. Be very careful with this (although there are good
126 use-cases) The xgettext msgid extractor may add the used msgid
127 to this namespace as well. To avoid that, add a harmless '+':
128 print __x(+"errors", _domain => 'global');
130 The extractor will not take the msgid when it is an expression.
132 The '+' has no effect on the string at runtime.
133 _expand => BOOLEAN
135 Indicates whether variables are to be filled-in.
136 _join => STRING
138 Which STRING to be used then an ARRAY is being filled-in.
139 _lang => ISO
141 [1.00] Override language setting from locale, for instance
142 because that is not configured correctly (yet). This does not
143 extend to prepended or appended translated message object.
144 _msgctxt => STRING
146 [1.22] Message context in the translation file, the traditional
147 use. Cannot be combined with "_context" on the same msgids.
148 _msgid => MSGID
150 The message label, which refers to some translation information.
151 Usually a string which is close the English version of the
152 message. This will also be used if there is no translation
153 possible/known.
154 Leading white-space "\s" will be added to "_prepend". Trailing
156 white-space will be added before "_append".
157 _plural => MSGID
159 Can be used together with "_count". This plural form of the
160 "_msgid" text is used to simplify the work of translators, and as
161 fallback when no translation is possible: therefore, this can
162 best resemble an English message.
163 White-space at the beginning and end of the string are stripped
165 off. The white-space provided by the "_msgid" will be used.
166 _prepend => STRING|MESSAGE
168 Text as STRING or MESSAGE object to be displayed before the
169 display of this message.
170 _to => NAME
172 Specify the NAME of a dispatcher as destination explicitly. Short
173 for "report {to => NAME}, ..." See to()
174 Accessors
176 $obj->append()
177 Returns the string or Log::Report::Message object which is appended
178 after this one. Usually "undef".
179 $obj->classes()
181 Returns the LIST of classes which are defined for this message;
182 message group indicators, as often found in exception-based
183 programming.
184 $obj->context()
186 Returns an HASH if there is a context defined for this message.
187 $obj->count()
189 Returns the count, which is used to select the translation
190 alternatives.
191 $obj->domain()
193 Returns the domain of the first translatable string in the
194 structure.
195 $obj->msgctxt()
197 The message context for the translation table lookup.
198 $obj->msgid()
200 Returns the msgid which will later be translated.
201 $obj->prepend()
203 Returns the string which is prepended to this one. Usually
204 "undef".
205 $obj->to( [$name] )
207 Returns the $name of a dispatcher if explicitly specified with the
208 '_to' key. Can also be used to set it. Usually, this will return
209 undef, because usually all dispatchers get all messages.
210 $obj->valueOf($parameter)
212 Lookup the named $parameter for the message. All pre-defined names
213 have their own method which should be used with preference.
214 example:
216 When the message was produced with
218 my @files = qw/one two three/;
220 my $msg = __xn "found one file: {file}"
221 , "found {nrfiles} files: {files}"
222 , scalar @files
223 , file => $files[0]
224 , files => \@files
225 , nrfiles => @files+0
226 , _class => 'IO, files'
227 , _join => ', ';
228 then the values can be takes from the produced message as
230 my $files = $msg->valueOf('files'); # returns ARRAY reference
232 print @$files; # 3
233 my $count = $msg->count; # 3
234 my @class = $msg->classes; # 'IO', 'files'
235 if($msg->inClass('files')) # true
236 Simplified, the above example can also be written as:
238 local $" = ', ';
240 my $msg = __xn "found one file: {files}"
241 , "found {_count} files: {files}"
242 , @files # has scalar context
243 , files => \@files
244 , _class => 'IO, files';
245 Processing
247 $obj->concat( STRING|$object, [$prepend] )
248 This method implements the overloading of concatenation, which is
249 needed to delay translations even longer. When $prepend is true,
250 the STRING or $object (other "Log::Report::Message") needs to
251 prepended, otherwise it is appended.
252 example: of concatenation
254 print __"Hello" . ' ' . __"World!";
256 print __("Hello")->concat(' ')->concat(__"World!")->concat("\n");
257 $obj->inClass($class|Regexp)
259 Returns true if the message is in the specified $class (string) or
260 matches the Regexp. The trueth value is the (first matching)
261 class.
262 $obj->toHTML( [$locale] )
264 [1.11] Translate the message, and then entity encode HTML volatile
265 characters.
266 [1.20] When used in combination with a templating system, you may
268 want to use "<content_for =" 'HTML'>> in
269 Log::Report::Domain::configure(formatter).
270 example:
272 print $msg->toHTML('NL');
274 $obj->toString( [$locale] )
276 Translate a message. If not specified, the default locale is used.
277 $obj->untranslated()
279 Return the concatenation of the prepend, msgid, and append strings.
280 Variable expansions within the msgid is not performed.
281
283 OPTIONS and VARIABLES
284 The Log::Report functions which define translation request can all have
285 OPTIONS. Some can have VARIABLES to be interpolated in the string as
286 well. To distinguish between the OPTIONS and VARIABLES (both a list of
287 key-value pairs), the keys of the OPTIONS start with an underscore "_".
288 As result of this, please avoid the use of keys which start with an
289 underscore in variable names. On the other hand, you are allowed to
290 interpolate OPTION values in your strings.
291 Interpolating
293 With the "__x()" or "__nx()", interpolation will take place on the
295 translated MSGID string. The translation can contain the VARIABLE and
296 OPTION names between curly brackets. Text between curly brackets which
297 is not a known parameter will be left untouched.
298 fault __x"cannot open open {filename}", filename => $fn;
300 print __xn"directory {dir} contains one file"
302 ,"directory {dir} contains {nr_files} files"
303 , scalar(@files) # (1) (2)
304 , nr_files => scalar @files # (3)
305 , dir => $dir;
306 (1) this required third parameter is used to switch between the
308 different plural forms. English has only two forms, but some languages
309 have many more.
310 (2) the "scalar" keyword is not needed, because the third parameter is
312 in SCALAR context. You may also pass " \@files " there, because ARRAYs
313 will be converted into their length. A HASH will be converted into the
314 number of keys in the HASH.
315 (3) the "scalar" keyword is required here, because it is LIST context:
317 otherwise all filenames will be filled-in as parameters to "__xn()".
318 See below for the available "_count" valure, to see how the "nr_files"
319 parameter can disappear.
320 Interpolation of VARIABLES
322 "Log::Report" uses String::Print to interpolate values in(translated)
324 messages. This is a very powerful syntax, and you should certainly
325 read that manual-page. Here, we only described additional features,
326 specific to the usage of "String::Print" in "Log::Report::Message"
327 objects.
328 There is no way of checking beforehand whether you have provided all
330 required values, to be interpolated in the translated string.
331 For interpolating, the following rules apply:
333 • Simple scalar values are interpolated "as is"
335 • References to SCALARs will collect the value on the moment that the
337 output is made. The "Log::Report::Message" object which is created
338 with the "__xn" can be seen as a closure. The translation can be
339 reused. See example below.
340 • Code references can be used to create the data "under fly". The
342 "Log::Report::Message" object which is being handled is passed as
343 only argument. This is a hash in which all OPTIONS and VARIABLES
344 can be found.
345 • When the value is an ARRAY, all members will be interpolated with
347 $" between the elements. Alternatively (maybe nicer), you can pass
348 an interpolation parameter via the "_join" OPTION.
349 local $" = ', ';
351 error __x"matching files: {files}", files => \@files;
352 error __x"matching files: {files}", files => \@files, _join => ', ';
354 Interpolation of OPTIONS
356 You are permitted the interpolate OPTION values in your string. This
358 may simplify your coding. The useful names are:
359 _msgid
361 The MSGID as provided with Log::Report::__() and Log::Report::__x()
362 _plural, _count
364 The PLURAL MSGIDs, respectively the COUNT as used with
365 Log::Report::__n() and Log::Report::__nx()
366 _textdomain
368 The label of the textdomain in which the translation takes place.
369 _class or _classes
371 Are to be used to group reports, and can be queried with inClass(),
372 Log::Report::Exception::inClass(), or
373 Log::Report::Dispatcher::Try::wasFatal().
374 . Example: using the _count
376 With Locale::TextDomain, you have to do
378 use Locale::TextDomain;
380 print __nx ( "One file has been deleted.\n"
381 , "{num} files have been deleted.\n"
382 , $num_files
383 , num => $num_files
384 );
385 With "Log::Report", you can do
387 use Log::Report;
389 print __nx ( "One file has been deleted.\n"
390 , "{_count} files have been deleted.\n"
391 , $num_files
392 );
393 Of course, you need to be aware that the name used to reference the
395 counter is fixed to "_count". The first example works as well, but is
396 more verbose.
397 Handling white-spaces
399 In above examples, the msgid and plural form have a trailing new-line.
401 In general, it is much easier to write
402 print __x"Hello, World!\n";
404 than
406 print __x("Hello, World!") . "\n";
408 For the translation tables, however, that trailing new-line is "over
410 information"; it is an layout issue, not a translation issue.
411 Therefore, the first form will automatically be translated into the
413 second. All leading and trailing white-space (blanks, new-lines, tabs,
414 ...) are removed from the msgid before the look-up, and then added to
415 the translated string.
416 Leading and trailing white-space on the plural form will also be
418 removed. However, after translation the spacing of the msgid will be
419 used.
420 Avoiding repetative translations
422 This way of translating is somewhat expensive, because an object to
424 handle the "__x()" is created each time.
425 for my $i (1..100_000)
427 { print __x "Hello World {i}\n", i => $i;
428 }
429 The suggestion that Locale::TextDomain makes to improve performance, is
431 to get the translation outside the loop, which only works without
432 interpolation:
433 use Locale::TextDomain;
435 my $i = 42;
436 my $s = __x("Hello World {i}\n", i => $i);
437 foreach $i (1..100_000)
438 { print $s;
439 }
440 Oops, not what you mean because the first value of $i is captured in
442 the initial message object. With Log::Report, you can do it (except
443 when you use contexts)
444 use Log::Report;
446 my $i;
447 my $s = __x("Hello World {i}\n", i => \$i);
448 foreach $i (1..100_000)
449 { print $s;
450 }
451 Mind you not to write: "for my $i" in above case!!!!
453 You can also write an incomplete translation:
455 use Log::Report;
457 my $s = __x "Hello World {i}\n";
458 foreach my $i (1..100_000)
459 { print $s->(i => $i);
460 }
461 In either case, the translation will be looked-up only once.
463
465 overload: as $function
466 When the object is used to call as $function, a new object is
467 created with the data from the original one but updated with the
468 new parameters. Implemented in "clone()".
469 overload: concatenation
471 An (accidental) use of concatenation (a dot where a comma should be
472 used) would immediately stringify the object. This is avoided by
473 overloading that operation.
474 overload: stringification
476 When the object is used in string context, it will get translated.
477 Implemented as toString().
478
480 This module is part of Log-Report distribution version 1.33, built on
481 July 17, 2021. Website: http://perl.overmeer.net/CPAN/
482
484 Copyrights 2007-2021 by [Mark Overmeer <markov@cpan.org>]. For other
485 contributors see ChangeLog.
486 This program is free software; you can redistribute it and/or modify it
488 under the same terms as Perl itself. See http://dev.perl.org/licenses/
489perl v5.34.0 2021-07-22 Log::Report::Message(3)