1Locale::Po4a::TransTractor(3pm) Po4a Tools Locale::Po4a::TransTractor(3pm)
2
6 Locale::Po4a::TransTractor - generic trans(lator ex)tractor.
7
9 The po4a (PO for anything) project goal is to ease translations (and
10 more interestingly, the maintenance of translations) using gettext
11 tools on areas where they were not expected like documentation.
12 This class is the ancestor of every po4a parser used to parse a
14 document, to search translatable strings, to extract them to a PO file
15 and to replace them by their translation in the output document.
16 More formally, it takes the following arguments as input:
18 - a document to translate;
20 - a PO file containing the translations to use.
22 As output, it produces:
24 - another PO file, resulting of the extraction of translatable strings
26 from the input document;
27 - a translated document, with the same structure than the one in input,
29 but with all translatable strings replaced with the translations
30 found in the PO file provided in input.
31 Here is a graphical representation of this:
33 Input document --\ /---> Output document
35 \ / (translated)
36 +-> parse() function -----+
37 / \
38 Input PO --------/ \---> Output PO
39 (extracted)
40
42 parse()
43 This is where all the work takes place: the parsing of input
44 documents, the generation of output, and the extraction of the
45 translatable strings. This is pretty simple using the provided
46 functions presented in the section INTERNAL FUNCTIONS below. See
47 also the SYNOPSIS, which presents an example.
48 This function is called by the process() function below, but if you
50 choose to use the new() function, and to add content manually to
51 your document, you will have to call this function yourself.
52 docheader()
54 This function returns the header we should add to the produced
55 document, quoted properly to be a comment in the target language.
56 See the section Educating developers about translations, from
57 po4a(7), for what it is good for.
58
60 The following example parses a list of paragraphs beginning with "<p>".
61 For the sake of simplicity, we assume that the document is well
62 formatted, i.e. that '<p>' tags are the only tags present, and that
63 this tag is at the very beginning of each paragraph.
64 sub parse {
66 my $self = shift;
67 PARAGRAPH: while (1) {
69 my ($paragraph,$pararef)=("","");
70 my $first=1;
71 my ($line,$lref)=$self->shiftline();
72 while (defined($line)) {
73 if ($line =~ m/<p>/ && !$first--; ) {
74 # Not the first time we see <p>.
75 # Reput the current line in input,
76 # and put the built paragraph to output
77 $self->unshiftline($line,$lref);
78 # Now that the document is formed, translate it:
80 # - Remove the leading tag
81 $paragraph =~ s/^<p>//s;
82 # - push to output the leading tag (untranslated) and the
84 # rest of the paragraph (translated)
85 $self->pushline( "<p>"
86 . $self->translate($paragraph,$pararef)
87 );
88 next PARAGRAPH;
90 } else {
91 # Append to the paragraph
92 $paragraph .= $line;
93 $pararef = $lref unless(length($pararef));
94 }
95 # Reinit the loop
97 ($line,$lref)=$self->shiftline();
98 }
99 # Did not get a defined line? End of input file.
100 return;
101 }
102 }
103 Once you've implemented the parse function, you can use your document
105 class, using the public interface presented in the next section.
106
108 Constructor
109 process(%)
110 This function can do all you need to do with a po4a document in one
111 invocation. Its arguments must be packed as a hash. ACTIONS:
112 a. Reads all the PO files specified in po_in_name
114 b. Reads all original documents specified in file_in_name
116 c. Parses the document
118 d. Reads and applies all the addenda specified
120 e. Writes the translated document to file_out_name (if given)
122 f. Writes the extracted PO file to po_out_name (if given)
124 ARGUMENTS, beside the ones accepted by new() (with expected type):
126 file_in_name (@)
128 List of filenames where we should read the input document.
129 file_in_charset ($)
131 Charset used in the input document (if it isn't specified, it
132 will try to detect it from the input document).
133 file_out_name ($)
135 Filename where we should write the output document.
136 file_out_charset ($)
138 Charset used in the output document (if it isn't specified, it
139 will use the PO file charset).
140 po_in_name (@)
142 List of filenames where we should read the input PO files from,
143 containing the translation which will be used to translate the
144 document.
145 po_out_name ($)
147 Filename where we should write the output PO file, containing
148 the strings extracted from the input document.
149 addendum (@)
151 List of filenames where we should read the addenda from.
152 addendum_charset ($)
154 Charset for the addenda.
155 new(%)
157 Create a new po4a document. Accepted options (but be in a hash):
158 verbose ($)
160 Sets the verbosity.
161 debug ($)
163 Sets the debugging.
164 Manipulating document files
166 read($$)
167 Add another input document data at the end of the existing array
168 "@{$self->{TT}{doc_in}}". The argument is the filename to read. If
169 a second argument is provided, it is the filename to use in the
170 references.
171 This array "@{$self->{TT}{doc_in}}" holds this input document data
173 as an array of strings with alternating meanings.
174 * The string $textline holding each line of the input text data.
175 * The string "$filename:$linenum" holding its location and called
176 as
177 "reference" ("linenum" starts with 1).
178 Please note that it does not parse anything. You should use the
180 parse() function when you're done with packing input files into the
181 document.
182 write($)
184 Write the translated document to the given filename.
185 This translated document data are provided by:
187 * "$self->docheader()" holding the header text for the plugin, and
188 * "@{$self->{TT}{doc_out}}" holding each line of the main
189 translated text in the array.
190 Manipulating PO files
192 readpo($)
193 Add the content of a file (which name is passed as argument) to the
194 existing input PO. The old content is not discarded.
195 writepo($)
197 Write the extracted PO file to the given filename.
198 stats()
200 Returns some statistics about the translation done so far. Please
201 note that it's not the same statistics than the one printed by
202 msgfmt --statistic. Here, it's stats about recent usage of the PO
203 file, while msgfmt reports the status of the file. It is a wrapper
204 to the Locale::Po4a::Po::stats_get function applied to the input PO
205 file. Example of use:
206 [normal use of the po4a document...]
208 ($percent,$hit,$queries) = $document->stats();
210 print "We found translations for $percent\% ($hit from $queries) of strings.\n";
211 is_po_uptodate()
213 Returns ($uptodate, $diagnostic) where $uptodate is whether the
214 input po and the output po match (if not, it means that the input
215 po should be updated) and $diagnostic is a string explaining why
216 the po file is not uptodate, when this happens.
217 Manipulating addenda
219 addendum($)
220 Please refer to po4a(7) for more information on what addenda are,
221 and how translators should write them. To apply an addendum to the
222 translated document, simply pass its filename to this function and
223 you are done ;)
224 This function returns a non-null integer on error.
226
228 Getting input, providing output
229 Four functions are provided to get input and return output. They are
230 very similar to shift/unshift and push/pop of Perl.
231 * Perl shift returns the first array item and drop it from the array.
233 * Perl unshift prepends an item to the array as the first array item.
234 * Perl pop returns the last array item and drop it from the array.
235 * Perl push appends an item to the array as the last array item.
236 The first pair is about input, while the second is about output.
238 Mnemonic: in input, you are interested in the first line, what shift
239 gives, and in output you want to add your result at the end, like push
240 does.
241 shiftline()
243 This function returns the first line to be parsed and its
244 corresponding reference (packed as an array) from the array
245 "@{$self->{TT}{doc_in}}" and drop these first 2 array items. Here,
246 the reference is provided by a string "$filename:$linenum".
247 unshiftline($$)
249 Unshifts the last shifted line of the input document and its
250 corresponding reference back to the head of
251 "{$self->{TT}{doc_in}}".
252 pushline($)
254 Push a new line to the end of "{$self->{TT}{doc_out}}".
255 popline()
257 Pop the last pushed line from the end of "{$self->{TT}{doc_out}}".
258 Marking strings as translatable
260 One function is provided to handle the text which should be translated.
261 translate($$$)
263 Mandatory arguments:
264 - A string to translate
266 - The reference of this string (i.e. position in inputfile)
268 - The type of this string (i.e. the textual description of its
270 structural role; used in Locale::Po4a::Po::gettextization(); see
271 also po4a(7), section Gettextization: how does it work?)
272 This function can also take some extra arguments. They must be
274 organized as a hash. For example:
275 $self->translate("string","ref","type",
277 'wrap' => 1);
278 wrap
280 boolean indicating whether we can consider that whitespaces in
281 string are not important. If yes, the function canonizes the
282 string before looking for a translation or extracting it, and
283 wraps the translation.
284 wrapcol
286 the column at which we should wrap (default: 76).
287 comment
289 an extra comment to add to the entry.
290 Actions:
292 - Pushes the string, reference and type to po_out.
294 - Returns the translation of the string (as found in po_in) so that
296 the parser can build the doc_out.
297 - Handles the charsets to recode the strings before sending them to
299 po_out and before returning the translations.
300 Misc functions
302 verbose()
303 Returns if the verbose option was passed during the creation of the
304 TransTractor.
305 debug()
307 Returns if the debug option was passed during the creation of the
308 TransTractor.
309 detected_charset($)
311 This tells TransTractor that a new charset (the first argument) has
312 been detected from the input document. It can usually be read from
313 the document header. Only the first charset will remain, coming
314 either from the process() arguments or detected from the document.
315 get_out_charset()
317 This function will return the charset that should be used in the
318 output document (usually useful to substitute the input document's
319 detected charset where it has been found).
320 It will use the output charset specified in the command line. If it
322 wasn't specified, it will use the input PO's charset, and if the
323 input PO has the default "CHARSET", it will return the input
324 document's charset, so that no encoding is performed.
325 recode_skipped_text($)
327 This function returns the recoded text passed as argument, from the
328 input document's charset to the output document's one. This isn't
329 needed when translating a string (translate() recodes everything
330 itself), but it is when you skip a string from the input document
331 and you want the output document to be consistent with the global
332 encoding.
333
335 One shortcoming of the current TransTractor is that it can't handle
336 translated document containing all languages, like debconf templates,
337 or .desktop files.
338 To address this problem, the only interface changes needed are:
340 - take a hash as po_in_name (a list per language)
342 - add an argument to translate to indicate the target language
344 - make a pushline_all function, which would make pushline of its
346 content for all languages, using a map-like syntax:
347 $self->pushline_all({ "Description[".$langcode."]=".
349 $self->translate($line,$ref,$langcode)
350 });
351 Will see if it's enough ;)
353
355 Denis Barbier <barbier@linuxfr.org>
356 Martin Quinson (mquinson#debian.org)
357 Jordi Vilalta <jvprat@gmail.com>
358Po4a Tools 2021-02-23 Locale::Po4a::TransTractor(3pm)