Qt Translation returns the same string instead of translation

Question

I am experiencing a strange Qt Translation problem.

Due to reasons I cannot change that involve legacy databases of translation tables, our 'natural language' is 'Enums'.

QString myString = tr("OUR_APP_MY_STRING");

I have a script that builds the *.TS files out of our databases to be used by Qt.

The entry in the *.TS files for english looks like this:

<message>
    <source>OUR_APP_MY_STRING</source>
    <translation>My String</translation>
</message>

The *.TS file loads fine into Qt Linguist. Everything there looks fine. "OUR_APP_MY_STRING" is found and its "English Translation" looks ok.

The QT project file has the *.TS files in the TRANSLATION sections I am using lRelease to generate the .QM files and putting them in the application's resources (.qrc) file.

In my application's setup function (called by main() after construction) I have the following code:

// initialize translator
this->currentTranslator = new QTranslator(instance());

if (this->currentTranslator->load(":/translation/myApp_en.qm"))
{
  this->installTranslator(this->currentTranslator);
  QString test = tr("OUR_APP_MY_STRING");  // <<----- problem. output is always "OUR_APP_MY_STRING"

}

Any ideas?

Answer 1

It's not clear what is instance() in this line

 this->currentTranslator = new QTranslator(instance());

But anyway, here's some things to check:

• Do you have something like this in YourProjectName.pro ?

RESOURCES += \
   resources.qrc 

(resources.qrc is the name I usually use. Replace with whatever name you choose.)

• Did you check the prefixes in your resources.qrc ? Are you sure there's a translation/ prefix in there? Something like this should also work:

  <RCC>
    <qresource prefix="/">
      <file>translation/YourProjectName_en.qm</file>
      <!-- other resources here -->
    </qresource>
  </RCC>

provided that you have YourProjectName_en.qm in a translation/ subdirectory.

This is what Works for Me™:

in main.cpp:

 QApplication app(argc, argv);
 QApplication::setApplicationName("MyApplication");
 QApplication::setApplicationVersion("4.4");
 QApplication::setOrganizationName("FUBAR");
 QApplication::setOrganizationDomain("www.fu.bar");

 QTranslator translator;
 translator.load(app.applicationName() + "_" + QLocale::system().name(), ":/ts");
 app.installTranslator(&translator);

in resources.qrc:

<RCC>
   <qresource prefix="/">
     <file>resources/pixmaps/exit.png</file>
     <!-- ... -->
     <file>ts/MyApplication_en.qm</file>
     <file>ts/MyApplication_es.qm</file>
   </qresource>
</RCC>

in MyApplication.pro:

 TRANSLATIONS += \
   ts/MyApplication_en.ts \
   ts/MyApplication_es.ts

 RESOURCES += \
   resources.qrc

 win32 {
   RC_FILE = win32.rc
 }

 OTHER_FILES += \
     win32.rc \
     TODO.txt

And here's a brief description of the project tree:

MyApplication
 ├── resources
 │   ├── pixmaps
 │   └── ...
 ├── (sources are here)
 ├── MyApplication.pro
 ├── resources.qrc
 ├── TODO.txt
 ├── ts
 │   ├── MyApplication_en.qm
 │   ├── MyApplication_en.ts
 │   ├── MyApplication_es.qm
 │   └── MyApplication_es.ts
 └── win32.rc

This is a very small project, sources are mixed with a few artifacts.

Edit:

I think you should try passing the filename and directory parts separated to the load method. In short, change this line

 if (this->currentTranslator->load(":/translation/myApp_en.qm"))

to this

 if (this->currentTranslator->load("myApp_en.qm", ":/translation/"))