"Language Reverts to English When Missing .qm File"

[shreya_agrawal]

So, I have 3 language options in my application, English and 2 others, say Language A and Language B. Suppose that the .qm file of B is missing. I select A and the UI translates to A. Then, I select B, I get an error message box, but the language shifts to English. I want it to remain A. I don't get what I am doing wrong. Here is the function where I install and remove the translator:

void LanguageSupport::onLanguageChanged(Language lang)
{
    if(lang == LanguageSupport::English) {
        qApp->removeTranslator(&translator);
    }

    else{
        QString filePath = getLanguageFilePath(lang);
        if(!translator.load(filePath)) {
            QMessageBox::critical(nullptr, "error", "Failed to load language translation file");
            return;
        }
        qApp->installTranslator(&translator);
    }
}

Note: I am not using this translator in any other file. Its a private member of the LanguageSupport class.

[Christian Ehrlicher]

@shreya_agrawal said in "Language Reverts to English When Missing .qm File":

I don't get what I am doing wrong.

You remove the old translator so how should it be used afterwards? You have to load the old ts file.

[shreya_agrawal]

Thank you for your reply!
The translator is only removed when I select English language. But when I select Language A and then Language B, the translator is not being removed.

[J.Hilk]

@shreya_agrawal seems like you're using the same stack allocated translator for everything:

removeTranslator(&translator)

!translator.load(filePath)

probably the reason.

[shreya_agrawal]

@J-Hilk
If I don't use the same translator, then how would it know which translator to remove when switching back to English?

[J.Hilk]

@shreya_agrawal keep a map of QTranslator pointers and the LanguageSupport enum as key?

[shreya_agrawal]

@J-Hilk
I tried implementing this approach, but still facing the same issue.

    // Load translators for all languages
    for (auto it = languageFiles.constBegin(); it != languageFiles.constEnd(); ++it) {
        QSharedPointer<QTranslator> translator = QSharedPointer<QTranslator>::create();
        if (translator->load(it.value())) {
            translators[it.key()] = translator;
        } else {
            qDebug() << "Failed to load translator for language:" << it.key();
        }
    }

void LanguageSupport::onLanguageChanged(Language lang)
{
    // Remove all translators
    for (auto it = translators.constBegin(); it != translators.constEnd(); ++it) {
        qApp->removeTranslator(it.value().data());
    }

    if(lang == LanguageSupport::English) {
        return;
    }

    auto translator = translators.value(lang);
    if (translator) {
        qApp->installTranslator(translator.data());
    } else {
        QMessageBox::critical(nullptr, "Error", "Failed to load language translation file");
    }
}

Am I doing something wrong in this?

[J.Hilk]

@shreya_agrawal maybe this ?

// Remove all translators
    for (auto it = translators.constBegin(); it != translators.constEnd(); ++it) {
        qApp->removeTranslator(it.value().data());
    }

seems like you now always remove all translators and do not reinstall any when the loading fails :D

[shreya_agrawal]

Ah! I got your point. Now, I am removing all translators only when English is selected and then reinstalling them for the respective languages and it works as intended. Thanks !