1Locale::Po4a::TransTracUtsoerr(3C)ontributed Perl DocumeLnotcaatlieo:n:Po4a::TransTractor(3)
2
3
4

NAME

6       Po4a TransTractor - Generic trans(lator ex)tractor.
7

DESCRIPTION

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
13       This class is the ancestor of every po4a parsers used to parse a docu‐
14       ment to search translatable strings, extract them to a po file and
15       replace them by their translation in the output document.
16
17       More formally, it takes the following arguments as input:
18
19       - a document to translate ;
20
21       - a po file containing the translations to use.
22
23       As output, it produces:
24
25       - another po file, resulting of the extraction of translatable strings
26         from the input document ;
27
28       - 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
32       Here is a graphical representation of this:
33
34          Input document --\                             /---> Output document
35                            \                           /       (translated)
36                             +-> parse() function -----+
37                            /                           \
38          Input po --------/                             \---> Output po
39                                                                (extracted)
40

FUNCTIONS YOUR PARSER SHOULD OVERRIDE

42       parse()
43           This is where all the work takes place: the parsing of input docu‐
44           ments, the generation of output, and the extraction of the trans‐
45           latable strings. This is pretty simple using the provided functions
46           presented in the section "INTERNAL FUNCTIONS" below. See also the
47           synopsis, which present an example.
48
49           This function is called by the process() function bellow, but if
50           you choose to use the new() function, and to add content manually
51           to your document, you will have to call this function yourself.
52
53       docheader()
54           This function returns the header we should add to the produced doc‐
55           ument, quoted properly to be a comment in the target language.  See
56           the section "Educating developers about translations", from
57           po4a(7), for what it is good for.
58

SYNOPSIS

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 format‐
62       ted, i.e. that '<p>' tags are the only tags present, and that this tag
63       is at the very beginning of each paragraph.
64
65        sub parse {
66          my $self = shift;
67
68          PARAGRAPH: while (1) {
69              my ($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
79                      # Now that the document is formed, translate it:
80                      #   - Remove the leading tag
81                      $paragraph =~ s/^<p>//s;
82
83                      #   - push to output the leading tag (untranslated) and the
84                      #     rest of the paragraph (translated)
85                      $self->pushline(  "<p>"
86                                      . $document->translate($paragraph,$pararef)
87                                      );
88
89                      next PARAGRAPH;
90                  } else {
91                      # Append to the paragraph
92                      $paragraph .= $line;
93                      $pararef = $lref unless(length($pararef));
94                  }
95
96                  # 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
104       Once you've implemented the parse function, you can use your document
105       class, using the public interface presented in the next section.
106

PUBLIC INTERFACE for scripts using your parser

108       Constructor
109
110       process(%)
111           This function can do all you need to do with a po4a document in one
112           invocation. Its arguments must be packed as a hash. ACTIONS:
113
114           a. Reads all the po files specified in po_in_name
115
116           b. Reads all original documents specified in file_in_name
117
118           c. Parses the document
119
120           d. Reads and applies all the addenda specified
121
122           e. Writes the translated document to file_out_name (if given)
123
124           f. Writes the extracted po file to po_out_name (if given)
125
126           ARGUMENTS, beside the ones accepted by new() (with expected type):
127
128           file_in_name (@)
129               List of filenames where we should read the input document.
130
131           file_in_charset ($)
132               Charset used in the input document (if it isn't specified, it
133               will try to detect it from the input document).
134
135           file_out_name ($)
136               Filename where we should write the output document.
137
138           file_out_charset ($)
139               Charset used in the output document (if it isn't specified, it
140               will use the po file charset).
141
142           po_in_name (@)
143               List of filenames where we should read the input po files from,
144               containing the translation which will be used to translate the
145               document.
146
147           po_out_name ($)
148               Filename where we should write the output po file, containing
149               the strings extracted from the input document.
150
151           addendum (@)
152               List of filenames where we should read the addenda from.
153
154           addendum_charset ($)
155               Charset for the addenda.
156
157       new(%)
158           Create a new Po4a document. Accepted options (but be in a hash):
159
160           verbose ($)
161               Sets the verbosity.
162
163           debug ($)
164               Sets the debugging.
165
166       Manipulating document files
167
168       read($)
169           Add another input document at the end of the existing one. The
170           argument is the filename to read.
171
172           Please note that it does not parse anything. You should use the
173           parse() function when you're done with packing input files into the
174           document.
175
176       write($)
177           Write the translated document to the given filename.
178
179       Manipulating po files
180
181       readpo($)
182           Add the content of a file (which name is passed in argument) to the
183           existing input po. The old content is not discarded.
184
185       writepo($)
186           Write the extracted po file to the given filename.
187
188       stats()
189           Returns some statistics about the translation done so far. Please
190           note that it's not the same statistics than the one printed by
191           msgfmt --statistic. Here, it's stats about recent usage of the po
192           file, while msgfmt reports the status of the file. It is a wrapper
193           to the Locale::Po4a::Po::stats_get function applied to the input po
194           file. Example of use:
195
196               [normal use of the po4a document...]
197
198               ($percent,$hit,$queries) = $document->stats();
199               print "We found translations for $percent\%  ($hit from $queries) of strings.\n";
200
201       Manipulating addenda
202
203       addendum($)
204           Please refer to po4a(7) for more information on what addenda are,
205           and how translators should write them. To apply an addendum to the
206           translated document, simply pass its filename to this function and
207           you are done ;)
208
209           This function returns a non-null integer on error.
210

INTERNAL FUNCTIONS used to write derivated parsers

212       Getting input, providing output
213
214       Four functions are provided to get input and return output. They are
215       very similar to shift/unshift and push/pop. The first pair is about
216       input, while the second is about output. Mnemonic: in input, you are
217       interested in the first line, what shift gives, and in output you want
218       to add your result at the end, like push does.
219
220       shiftline()
221           This function returns the next line of the doc_in to be parsed and
222           its reference (packed as an array).
223
224       unshiftline($$)
225           Unshifts a line of the input document and its reference.
226
227       pushline($)
228           Push a new line to the doc_out.
229
230       popline()
231           Pop the last pushed line from the doc_out.
232
233       Marking strings as translatable
234
235       One function is provided to handle the text which should be translated.
236
237       translate($$$)
238           Mandatory arguments:
239
240           - A string to translate
241
242           - The reference of this string (ie, position in inputfile)
243
244           - The type of this string (ie, the textual description of its
245             structural role ; used in Locale::Po4a::Po::gettextization() ;
246             see also po4a(7), section Gettextization: how does it work?)
247
248           This function can also take some extra arguments. They must be
249           organized as a hash. For example:
250
251             $self->translate("string","ref","type",
252                              'wrap' => 1);
253
254           wrap
255               boolean indicating whether we can consider that whitespaces in
256               string are not important. If yes, the function canonizes the
257               string before looking for a translation or extracting it, and
258               wraps the translation.
259
260           wrapcol
261               The column at which we should wrap (default: 76).
262
263           comment
264               An extra comment to add to the entry.
265
266           Actions:
267
268           - Pushes the string, reference and type to po_out.
269
270           - Returns the translation of the string (as found in po_in) so that
271             the parser can build the doc_out.
272
273           - Handles the charsets to recode the strings before sending them to
274             po_out and before returning the translations.
275
276       Misc functions
277
278       verbose()
279           Returns if the verbose option was passed during the creation of the
280           TransTractor.
281
282       debug()
283           Returns if the debug option was passed during the creation of the
284           TransTractor.
285
286       detected_charset($)
287           This tells TransTractor that a new charset (the first argument) has
288           been detected from the input document. It can usually be read from
289           the document header. Only the first charset will remain, coming
290           either from the process() arguments or detected from the document.
291
292       get_out_charset()
293           This function will return the charset that should be used in the
294           output document (usually useful to substitute the input document's
295           detected charset where it has been found).
296
297           It will use the output charset specified in the command line. If it
298           wasn't specified, it will use the input po's charset, and if the
299           input po has the default "CHARSET", it will return the input docu‐
300           ment's charset, so that no encoding is performed.
301
302       recode_skipped_text($)
303           This function returns the recoded text passed as argument, from the
304           input document's charset to the output document's one. This isn't
305           needed when translating a string (translate() recodes everything
306           itself), but it is when you skip a string from the input document
307           and you want the output document to be consistent with the global
308           encoding.
309

FUTURE DIRECTIONS

311       One shortcoming of the current TransTractor is that it can't handle
312       translated document containing all languages, like debconf templates,
313       or .desktop files.
314
315       To address this problem, the only interface changes needed are:
316
317       - take a hash as po_in_name (a list per language)
318
319       - add an argument to translate to indicate the target language
320
321       - make a pushline_all function, which would make pushline of its con‐
322         tent for all language, using a map-like syntax:
323
324             $self->pushline_all({ "Description[".$langcode."]=".
325                                   $self->translate($line,$ref,$langcode)
326                                 });
327
328       Will see if it's enough ;)
329

AUTHORS

331        Denis Barbier <barbier@linuxfr.org>
332        Martin Quinson (mquinson#debian.org)
333        Jordi Vilalta <jvprat@gmail.com>
334
335
336
337perl v5.8.8                       2008-06-01     Locale::Po4a::TransTractor(3)
Impressum