QT - copying a file to AppData

Question

My program prompts the user to select a file to process. My program processes it and it tries to save the file to AppData.

This is how I do it:

QSettings settings(QSettings::IniFormat, QSettings::UserScope, "FlameTool", "FlameTool");
addin_path = QFileInfo(settings.fileName()).absolutePath() + "/addins/" + id + ".limod" ;
qDebug(addin_path.toLocal8Bit());

if(QFile::copy(QDir::toNativeSeparators(file_passed),QDir::toNativeSeparators(addin_path)))
    qDebug("copied");
else
    qDebug("not copied");

Everytime this part of code is executed, it outputs "not copied". How can I copy the file?

Answer 1

In order to do what you want, I would like to advice using QStandardPaths class instead:

Set the application name in, for example, main.cpp

int main(...)
{
    [..]
    a.setApplicationName("FlameTool");
}

Copy the file:

QString addin_path = QStandardPaths::writableLocation(QStandardPaths::DataLocation);
QDir dir(addin_path);
if (!dir.exists())
    dir.mkpath(addin_path);
if (!dir.exists("addins"))
    dir.mkdir("addins");

dir.cd("addins");
addin_path = dir.absoluteFilePath(id + ".limod");
if (QFile::exists(addin_path))
    QFile::remove(addin_path);

if(QFile::copy(file_passed, addin_path))
    qDebug("copied");
else
    qDebug("not copied");

Please also note that:

Note that if a file with the name newName already exists, copy() returns false (i.e. QFile will not overwrite it).

Answer 2

Firstly, you should remove any existing (because it will prevent copying as QFile::copy does not overwrite any existing file) file and warn if not possible to remove. Secondly you should validate the destination path.