[Interest] Question about advice regarding dynamicSortFilter of QSFPM in the docs

[Elvis Stansvik]

Hi all,

I've used QSortFilterProxyModel in the past, but it was quite a while
ago and now I'm a little confused by the advice given in the docs.

The description of the dynamicSortFilter property [1] reads:

"Note that you should not update the source model through the proxy
model when dynamicSortFilter is true. For instance, if you set the
proxy model on a QComboBox, then using functions that update the
model, e.g., addItem(), will not work as expected. An alternative is
to set dynamicSortFilter to false and call sort() after adding items
to the QComboBox.

The default value is true."

I can't remember this restriction from when I've worked with it
before, and in the class description, underneath the second code
snippet, it says:

"Any changes made through the QSortFilterProxyModel are applied to the
original model."

As if it is safe to update the model through the QSFPM at this point,
even if it is speaking of one where dynamicSortFilter is true (the
default).

Surely it must be possible to use a QSFPM with dynamicSortFilter set
to true as the model of some view which also provides editing (and
consequently will make its changes through the QSFPM)? Or is that
simply not a supported use case? If I use dynamicSortFilter, must I
always make my changes to the source model?

Grateful for any advice,
Elvis

[1] http://doc.qt.io/qt-5/qsortfilterproxymodel.html#dynamicSortFilter-prop
[2] http://doc.qt.io/qt-5/qsortfilterproxymodel.html#details