How to add non compilable configuration file into QT Project? - c++

Question

I have a .txt file in QT project, where I store settings parameters for my app. If I read it that way
void MainWindow::ReadApplicationSettings()
{
QFile cfgFile("config.txt");
if(!cfgFile.exists())
{
qDebug() << "Cannot find config file.";
}
else
{
ParseConfigFile(cfgFile);
SetCfg();
}
cfgFile.close();
}
And Parse it:
void MainWindow::ParseConfigFile(QFile &cfgFile)
{
QString line;
if (cfgFile.open(QIODevice::ReadOnly | QIODevice::Text))
{
QTextStream stream(&cfgFile);
while (!stream.atEnd())
{
line = stream.readLine();
std::istringstream iss(line.toStdString());
std::string id, eq, val;
bool error = false;
if (!(iss >> id))
{
error = true;
}
else if (id[0] == '#')
{
continue;
}
else if (!(iss >> eq >> val >> std::ws) || eq != "=" || iss.get() != EOF)
{
error = true;
}
if (error) { throw std::runtime_error("Parse error"); }
cfgMap[id] = std::stoi(val);
}
}
}
The file exists and when the parsing begin the content of the file is empty
The result of: line = stream.readLine(); is "".
If I add the file like a resource file and opened this way:
QFile cfgFile(":config.txt");
It's working correct, but the problem is that the config file is compiled and when you have to change some value, the project must be rebuild to take effect
I tried to compose the path like that QDir::currentPath + "/config.txt", but not working as well.

Answer 1

Another option is the undocumented feature "file_copies" in Qt 5.6 that you can use like this:
CONFIG += file_copies
configfiles.path = $$OUT_PWD
configfiles.files = $$PWD/config.txt
COPIES += configfiles
Found here: https://stackoverflow.com/a/54162789/6842395
If you don't like this method, that post has some more options to choose.
By the way, loooking at your ParseConfigFile() method seems that your config.txt is a collection of lines with the format: key = value, very similar to a classic INI file. Maybe you could use QSettings third constructor like this:
QSettings settings("config.txt", QSettings::IniFormat);

Answer 2

You can use QMAKE_EXTRA_TARGET in your profile like:
copyfile.commands += $${QMAKE_COPY} $$system_path($$PWD/config.txt) $$system_path($$DESTDIR/)
first.depends = $(first) copyfile
QMAKE_EXTRA_TARGETS += first copyfile
But ensure your $$DESTDIR is correct.