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Coding for translation

12,837 bytes added, 17:55, 5 October 2021
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Textual reports
Coding guidelines to enable easy and correct translation of strings on the User Interface.
[[Category:Translators/Categories]][[Category:Developers/Tutorials]][[Category:Developers/General]]
==Introduction==
Gramps has always been internationalized (seehttp: https://gramps-project.org/introduction-WP/2006/04/looking-back-over-5-years/ ).Therefore, all strings meantfor the user should always be flagged for translation.
In order to be considered for inclusion in the offical official Gramps release, any piece of code must support internationalization. What this means is that the Python module must support [[Translating Gramps|translations]] into different languages. Gramps provides support to make this as easy as possible for the developer. For enabling, a language code must be set on the ''configure.in'' file into ''[[Template:Gramps_translations#ALL_LINGUAS |ALL_LINGUAS]]'' section.
==How to allow translations==
Example 1:
print ("Hello world!")
In this example, the string will always be printed as specified.
=== More complicated translations ===
 
In addition to <tt>gettext</tt>, GrampsTranslation offers two more specialized retrieval functions, <tt>ngettext</tt> and <tt>sgettext</tt>.
In some strings, it's necessary to specify different translations depending upon the number of an argument. For example,
We'd code that in python as follows:
_ = glocale.get_translation()translation.gettextngettext
_(George Smith and Annie Jones have %(num)d child, George Smith and Annie Jones have %(num)d children, n) % {num : n}
In other cases, it's necessary to provide a hint to translators, <abbr title="exempli gratia - Latin phrase meaning 'for example'">e.g.</abbr>,
_(Remaining names | rest)
We're making sure that the translators know that this message id means "what's left" rather than "take a nap". When the file is translated, this is no problem, because the translation doesn't include the hint -- but if the user is working in English, we don't want him to see the hint, so we need to alias _ to sgettext:
_ = glocale.get_translation()translation.sgettext Often you need to combine them. While <tt>ngettext</tt> and <tt>sgettext</tt> can each handle plain strings, neither can handle the other's strings. Fortunately the <tt>intltool</tt> message extractor is pretty stupid, so any function name that ends in either <tt>_</tt> or <tt>gettext</tt> will work. This will work pretty well:  _ = glocale.translation.gettext N_ = glocale.translation.ngettext S_ = glocale.translation.sgettext Obviously you would pass the translatable string to the right function. 
=== Encoding ===
String handling can be a bit tricky in a localized environment. Grampsso it's translation facility will always return Unicode-encoded strings. For as long as it is necessary to support both Python2 and Python3, important that developers will need to understand Unicode string handling in both versions of the language.
If you This is mostly a problem for Microsoft Windows™: Mac OSX and Linux use non ASCII characters in UTF8 for just about everything if the locale is set up correctly (and we try to do that when Gramps starts up), so one can get away with a string literal lot of encoding mistakes on those platforms. Windows™ on the string must other hand uses a slightly modified version of UTF16 for file names and retains the old DOS [http://en.wikipedia.org/wiki/Code_page code page] system for encoding output to cmd.exe. The take-away is that if you need to mess with input or output encoding, be Unicodesure to test on both Linux and Windows before deciding that you're done. If you're not set up for multiple-platform testing arrange with someone,, who can test for you on the platform you don't have.
====Python 2====Python 2.7 has two text classes, <tt>[https://docs.python.org/2.7/library/functions.html#str str]</tt> and <tt>[https://docs.python.org/2.7/library/functions.html#unicode unicode]</tt>. <tt>Unicode</tt> objects are encoded in UTF16 internally on most platforms, and most python '''output''Don't functions will do thisthe right thing with them. One caveat here:''' print _passing both <tt>unicodes</tt> and <tt>strs</tt> to <tt>os.path.join(u"Eg)</tt> will return a <tt>str</tt>, valid values so either make sure when constructing a path that all arguments are 12<tt>unicodes</tt> or convert the result.0154, 50° 52′ 21.92″N")
Because The bsddb module that ships with Python2 is stupid about paths and requires that they be encoded in the <tt>u</tt> prefix was removed for Python 3file system encoding.0-3.2. (It was restored This is handled in 3gramps/gen/db/write.3 for compatibility py with 2.7, but it's not necessary._encode()Instead, put in the first line of the module # *-* coding: utf-u *-*then and independently in the imports section from __future__ import unicode_literalswhich makes all of the literals unicodea few other places. Make sure that your editor is set up to save utf-8!
Strings from the operating system, including environment variables, are a problem on Windows™; The os module uses for input the [http://msdn.microsoft.com/en-us/library/windows/desktop/dd317766%28v=vs.85%29.aspx ANSI API] to the Windows SDK, which interprets the value of the environment variable according to the active code page and produces a <tt>str</tt>, converting any codepoints > 0xff to ? and often misinterpreting those between 0x0f and 0xff if the encoding of the input happens to be something other than the active system codepage. Once this is done it is quite difficult to get non-ASCII pathnames back into a useable form, so gramps/gen/constfunc.py provides a get_env_var() function that uses the [http://msdn.microsoft.com/en-us/library/windows/desktop/dd374081(v=vs.85).aspx Unicode API] to instead. Always use that function to read environment variables which might include non-ASCII characters and avoid using os-module functions for reading paths. By default string constants in Python 2 are <tt>str</tt>. =Into glade ===Python 3====Python 3 also provides two test classes, <tt>[https://docs.python.org/3/library/stdtypes.html#text-sequence-type-str str]</tt> and <tt>[https://docs.python.org/3/library/stdtypes.html#binary-sequence-types-bytes-bytearray-memoryview bytes]</tt>. In Python 3, <tt>str</tt> is the unicode type and <tt>bytes</tt> is text encoded some other way. Everything pretty much "just works". ====Portability Functions and constants====We've provided a couple of functions in gramps/gen/constfunc.py to ease conversion of <tt>strs</tt> to <tt>unicodes</tt>; these include the necessary tests to portably do the right thing regardless of what's passed to them and according to which version of Python is in use:* <tt>cuni</tt> is an alias for [https://docs.python.org/2.7/library/functions.html#unicode unicode] in Python 2 and for [https://docs.python.org/3/library/functions.html#func-str str] in Python 3. This has no protective checks so use it with care.* <tt>conv_to_unicode(string, encoding='utf8')</tt>: This ensures that its return value is a Unicode string which has been converted from a non-Unicode in the <tt>encoding</tt>, which defaults to UTF8 for ease of use with the GUI.* <tt>get_env_var(string, default=None)</tt>: On Windows™ in Python2, uses the <tt>ctypes</tt> module to invoke the Microsoft Unicode API to read the value of an environment variable and return a Unicode; otherwise returns the value from the <tt>os.environ</tt> array.There are also two constants:* <tt>STRTYPE</tt> is an alias for [https://docs.python.org/2.7/library/functions.html#basestring basestring] in Python 2 and for [https://docs.python.org/3/library/stdtypes.html#text-sequence-type-str str] in Python 3. It can be used to test whether an object is a text-type.* <tt>UNITYPE</tt> is an alias for [https://docs.python.org/2.7/library/functions.html#unicode unicode] in Python 2 and for [https://docs.python.org/3/library/stdtypes.html#text-sequence-type-str str] in Python 3. It can be used to test whether an object is already encoded in Unicode. ====For portable string handling on all platforms and for all locales====* Localized strings returned from gettext, ngettext, <abbr title="et cetera - Latin phrase meaning 'and so on'">etc.</abbr> are always unicode* Text files should always be encoded in UTF8. The easy and portable way to do this is to:*: <pre>import io</pre>*: <pre>fh = io.open(filepath, mode, encoding='utf8')</pre>*: where ''mode'' is one of r, rw, r+, or w+. ''Don't open these files in binary mode!'' Pass unicode-type strings to fh.write() and expect the same from fh.read().* Always read environment variables with <tt>constfuncs.get_env_var()</tt> if there's any chance that it will contain a non-ASCII character.* Use <tt>from __future__ import unicode_literals</tt> in any source filewhich might present strings to the user or to the operating system.*:When creating string literals, '''don't do this:'''*:<pre>print _(u"Eg, valid values are 12.0154, 50° 52′ 21.92″N")</pre>*:Because the <tt>u</tt> prefix was removed for Python 3.0-3.2. (It was restored in 3.3 for compatibility with 2.7, but it's not necessary.)*:Instead, put in the first line of the module*:<pre># *-* coding: utf-8 *-*</pre>*:then in the imports section*:<pre>from __future__ import unicode_literals</pre>*:which makes all of the literals unicode. '''Make sure that your editor is set up to save utf-8!''' ===Glade files===
Just enable the translatable attribute on an XML element.
See [[Accessibility]].
===Into addons pluginsAddons===
External addons often need to provide their own message catalogs. To pull one in, usethis instead of the usual. from gramps.gen.const import import GRAMPS_LOCALE as glocale
_ = glocale.get_addon_translator(__file__).gettext
or if you need more than one retrieval function:
_translation = glocale.get_addon_translator(__file__)
_ = _translation.gettext
S_ = _translation.sgettext
The addon translator is another instance of GrampsTranslation, so the rules for creatingtranslatable strings and for retrieving the translated values are the same as for internal modules. See [[Addons_DevelopmentAddons_development#Localization|Addons development]] for more details.
==How it works==
* [[Translation_environment20|2.0.x]]
* [[Translation_environment22|2.2.x to Gramps 3.4.x]]
* [[Translation_environment4|TrunkGramps 4.0.x to 5.1.x]]
There are two stages to getting a translation to work.
* [[Translation_environment22#Files_and_directory|2.2.x to Gramps 3.4.x]]
* [[Translation_environment4#Files_and_directory|TrunkGramps 4.0.x, 5.1.x]]
==Tips for writing a translatable Python module==
===Use complete sentences===
Don't build up a sentence from phrases. Because a sentence is ordered in a particular way in your language does not mean that it is ordered the same way in another. Providing the entire sentence as a single unit allows the translator to make a meaningful translation. Do not concatenate phrases or terms as they will then show up as separate phrases or terms to be translated and the complete sentence may then show up incorrectly, especially in right-to-left languages (Arabic, Hebrew, <abbr title="et cetera - Latin phrase meaning 'and so on'">etc.</abbr>).
===Use named %s/%d values===
Python provides a powerful mechanism that allows the reordering of %s values in a string. A translator may need to rearrange the structure of a sentence, and it may not match the order you chose. For example:
===Provide support for plural forms.===
Plurals are handled differently in various languages. Whilst English or German have a singular and a plural form, other languages like Turkish don't distinguish between plural or singular and there are languages which use different plurals for different numbers, <abbr title="exempli gratia - Latin phrase meaning 'for example'">e.g. </abbr>, Polish.
Gramps provides a [[Translating_Gramps#Plural_forms|plural forms]] support, useful for locales with multiples plurals according to a number (''often slavic based languages'') or for Asian family languages (''singular = plural'').
===Object classes===
Gramps often displays names of primary objects (''Person, Family, Event, <abbr title="et cetera - Latin phrase meaning 'and so on'">etc .</abbr> ...''), for being consistent on displayed strings (also in english!), there is a ''trans_objclass(objclass_str)'' function on TransUtils module.
So, when we need to display the primary object name in lower case into a sentence, we can use this function.
will display:
See ''the person'' details # or See ''the family, the event, <abbr title="et cetera - Latin phrase meaning 'and so on'">etc.</abbr> ...'' details
Make ''the person'' active
Instead of "free form" text that talks about
<abbr title="exempli gratia - Latin phrase meaning 'for example'">e.g. </abbr>,
son '''of %s'''
better would be for example some tabulated format like this:
daughter: %s
which doesn't require genitive.
 
===Punctuation===
 
Use of commas, semicolons and spacing can be different than into english.
Remember, simple is better, maybe try to limit punctuation marks.
 
====definition====
 
<pre>
$ python3
>>> import string
>>> print(string.punctuation)
!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~
</pre>
 
====locale case====
 
In French, a space is required before or after some punctuation marks and symbols, like
<pre> : ; « » ! ? % $ # .</pre>
 
* GtkBuilder (editors, configuration dialogs) can provide a default colon after the string without spacing,
so need some extra-testing and customization for some translators. <abbr title="exempli gratia - Latin phrase meaning 'for example'">e.g.</abbr>, in french
 
<pre>
#: ../gramps/gen/plug/report/stdoptions.py:257 ../gramps/gui/configure.py:1222
msgid "Date format"
msgstr "Format des dates "</pre>
 
<pre>
# comté (Canada)
#: ../gramps/gui/configure.py:617
#: ../gramps/gui/editors/displaytabs/addrembedlist.py:75
#: ../gramps/plugins/view/repoview.py:92
msgid "State/County"
msgstr "Province/Comté "</pre>
 
<pre>
# L'espace final est pour précéder le « : » codé en dur.
#: ../gramps/gui/configure.py:1332
msgid "Status bar"
msgstr "Barre d'état "
</pre>
 
===Deferred key on lists===
 
In most coding situations, strings are translated where they are coded. Occasionally however, you need to mark strings for translation, but defer actual translation until later. A classic example is:
<pre>
animals = ['mollusk',
'albatross',
'rat',
'penguin',
'python', ]
for a in animals:
print(a)
</pre>
Here, you want to mark the strings in the animals list as being translatable, but you don’t actually want to translate them until they are printed.
 
Here is one way you can handle this situation:
<pre>
def _(message): return message
 
animals = [_('mollusk'),
_('albatross'),
_('rat'),
_('penguin'),
_('python'), ]
del _
for a in animals:
print(_(a))
</pre>
This works because the dummy definition of _() simply returns the string unchanged. And this dummy definition will temporarily override any definition of _() in the built-in namespace (until the del command). Take care, though if you have a previous definition of _() in the local namespace.
 
Note that the second use of _() will not identify “a” as being translatable to the gettext program, because the parameter is not a string literal.
 
Another way to handle this is with the following example:
<pre>
def _T_(message): return message
 
animals = [_T_('mollusk'),
_T_('albatross'),
_T_('rat'),
_T_('penguin'),
_T_('python'), ]
for a in animals:
print(_(a))
</pre>
In this case, you are marking translatable strings with the function _T_(), which won’t conflict with any definition of _().
 
See [https://docs.python.org/dev/library/gettext.html#deferred-translations deferred translations]
 
Current custom key on gramps code is '''_T_'''. Set as xgettext flag on [https://github.com/gramps-project/gramps/blob/master/po/genpot.sh#L6 shell script] and [https://github.com/gramps-project/gramps/blob/master/po/update_po.py#L716 python interface], generating the translation strings template.
 
==Changing translated text message in the source code==
One of the severities in our bug tracker is "text", which ranks up as easier than "tweak" and "minor", but more difficult than "trivial". If a bug is concerned with readability or correctness of a text that Gramps outputs, whether in GUI, in a console error message, or in a produced report, then "text" is the severity to use. So why is it more than "trivial"?
 
As described above, any translated text in the source code gets reflected into tens of *.po files, maintained by the translators. So every time you just change it in the source, ALL the translators need to do the translation again. Normally, the translation environment will give a prudent suggestion, but there is still a manual approval step. If you check in the change, the string will not be translated until the translators pick it up.
 
This is why, if what you change is just a couple of spelling mistakes, a missing comma in the middle, or maybe an extra space somewhere in the message, it's a good idea to save the translators' work, by doing a global search and replace of your source message text in the *.po files, and committing these along with your change.
 
For short enough messages, that don't span multiple lines in the *po files, you can do it by executing
perl -pi -e 's/YOUR MESSAGE BEFORE CORRECTION/your message after correction/g;' *.po *.pot
in the po/ directory. Make sure you do a "git diff" and observe the results make sense. (You'll probably have to escape some characters in the regular expression, such as | or .).
 
To make it easier to port your changes across multiple branches, it's a good idea to separate the changes in the source tree from the po/ ones. This way, you'll be able to quickly re-apply the source changes using normal cross-branch porting workflow (such as `git cherry-pick'), and then adjust and re-run the search-and-replace in the po/ on the new branch, because, most likely, it won't reapply due to the differences in the .po layout.
 
{{man note| Note |To stress it again, only do it for text change that didn't change how it is going to be translated. If you'd like your change to be somehow reflected in the translations, let the translators do the work instead.}}
==Textual reports==
Since Starting with Gramps-3.2 we are able to select the language for textual reports, see [http://www.gramps-project.org/bugs/view.php?id=feature {{bug|2371 this feature]}}.
Currently For Gramps it was only available on Ancestor report (3.2.x) and detailed reports (3.3.x). The capability for translated-output was added to some more (gramps core) reports, in the gramps40 branch, before gramps 4.0.0 was released. So more than the "three original reports" now have had this [https://gramps-project.org/bugs/view.php?id=2371#c33601 feature request implemented].
For providing this option:
self.__get_date(event.get_date_object())
self.__get_type(event.get_type())
 
==See also==
* [[Coding_for_translation|Coding for Translation]]
* [[Translating_Gramps_using_Weblate|Translating Gramps using Weblate]]
[[Category:Translators/Categories]]
[[Category:Developers/Tutorials]]
[[Category:Developers/General]]
[[Category:Addons]]
[[Category:Plugins]]
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