How to save text in QLineEdits in PyQt even if the Widget gets closed?

Question

Hello I have made a GUI for my script using PyQt I have a couple of Line edit ands a couple of buttons

(.....) = (self.(.....).text()) which I use that text for my

Answer 1

For an older application, it implements the functions that saved the states of the widgets and restored them.

In order for it to work properly, the application must meet the following requirements:

• You have to set OrganizationName, OrganizationDomain and ApplicationName.

• Each widget that you want to save the state must have an objectName

• You must use restore() when you want to restore the states, a good option is after creating all the widgets.

• You must use save() when you want to save the states, a good place would be closeEvent().

In the next part I show an example:

import sys

from PyQt5 import QtWidgets, QtCore

# for PyQt4 change QtWidget to QtGui and PyQt5 to PyQt4


def restore(settings):
    finfo = QtCore.QFileInfo(settings.fileName())
    if finfo.exists() and finfo.isFile():
        for w in QtWidgets.qApp.allWidgets():
            mo = w.metaObject()
            if w.objectName() and not w.objectName().startswith("qt_"):
                settings.beginGroup(w.objectName())
                for i in range( mo.propertyCount(), mo.propertyOffset()-1, -1):
                    prop = mo.property(i)
                    if prop.isWritable():
                        name = prop.name()
                        val = settings.value(name, w.property(name))
                        if str(val).isdigit():
                            val = int(val)
                        w.setProperty(name, val)
                settings.endGroup()

def save(settings):
    for w in QtWidgets.qApp.allWidgets():
        mo = w.metaObject()
        if w.objectName() and not w.objectName().startswith("qt_"):
            settings.beginGroup(w.objectName())
            for i in range(mo.propertyCount()):
                prop = mo.property(i)
                name = prop.name()
                if prop.isWritable():
                    settings.setValue(name, w.property(name))
            settings.endGroup()


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setObjectName("widget")
        self.init_ui()
        self.settings = QtCore.QSettings()
        print(self.settings.fileName())
        restore(self.settings)

    def init_ui(self):
        lay = QtWidgets.QVBoxLayout(self)
        lineEdit1 = QtWidgets.QLabel("label")
        lineEdit1.setObjectName("label")
        lineEdit2 = QtWidgets.QLineEdit()
        lineEdit2.setObjectName("lineEdit2")
        combobox = QtWidgets.QComboBox()
        combobox.addItems(["1", "2", "3"])
        combobox.setObjectName("combo")
        lay.addWidget(lineEdit1)
        lay.addWidget(lineEdit2)
        lay.addWidget(combobox)

    def closeEvent(self, event):
        save(self.settings)
        super().closeEvent(event)


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    QtCore.QCoreApplication.setOrganizationName("Eyllanesc")
    QtCore.QCoreApplication.setOrganizationDomain("eyllanesc.com")
    QtCore.QCoreApplication.setApplicationName("MyApp")
    ex = Widget()
    ex.show()
    sys.exit(app.exec_())

---

Update:

In the case that you use Qt Designer it is no longer necessary to place the objectsNames because they are already established, but on the other hand the class that provides Qt Designer is not a widget, but a class that is responsible for filling a widget, so we must create the widget to be able to overwrite the closeEvent method as shown below:

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        ...
    def retranslateUi(self, MainWindow):
        ...

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setupUi(self)
        self.settings = QtCore.QSettings()
        restore(self.settings)

    def closeEvent(self, event):
        save(self.settings)
        super().closeEvent(event)

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    QtCore.QCoreApplication.setOrganizationName("Eyllanesc")
    QtCore.QCoreApplication.setOrganizationDomain("eyllanesc.com")
    QtCore.QCoreApplication.setApplicationName("MyApp")
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())