QSqlTableModel - Check for invalid cells in QTableView?

[R-P-H]

Hi, I have a QSqlTableModel set on a QTableView. When adding or updating a row I do not want to allow empty text in a specific column.

On submit, I would like a messagebox to show and the focus set back on the invalid cell.

I haven't been able to find a simplified way to do this. I am aware of the beforeInsert() and beforeUpdate() signals where I could check if the data is valid, however I don't know how to stop the insertion/update if record is invalid.

[JonB]

@R-P-H
I think there are various possibilities depending on exactly what you want. Here are some suggestions:

• For the specific case of "don't allow empty" you could place a validator on the generated edit widget.
• To refuse a value for a certain index you could override setData() and return false.
• To validate all data you could override submit()/submitAll() and have them return false. However with these I don't think you know which things have changed.
• Editing from a QTableView is done via an item delegate. Normally it generates a suitable delegate widget. You can provide your own subclassed delegate (QStyledItemDelegate). From https://doc.qt.io/qt-6/qabstractitemdelegate.html you can implement your own setModelData() which refuses to submit the data to the model if it considers it invalid. This might be a suitable place to show the user a message box.

[artwaw]

@R-P-H Dive into model to verify data input from the view is unnecessary in this case. Validator is the way to go, like @JonB suggested.

[R-P-H]

From what I've seen online, the QValidator approach requires subclassing QItemDelegate and it's setData() method. How is this different from the last point suggested ?