Send string signal from combobox in qml - qml

Question

I'm trying to send a string from combobox to an api. Unfortunately nothing is being sent.
main.qml
import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.15
Window {
id: mainWindow
width: 1120
height: 680
visible: true
Rectangle {
id: mainBody
color: "#F4F4F5"
anchors.fill: parent
ComboBox {
id: comboBox
x: 219
y: -9
width: 504
height: 40
model: [ "hp", "lenovo", "acer"]
}
Button {
id: bt
width: 24
height: 24
onClicked: backend.add(comboBox.text)
}
}
Connections {
target: backend
}
}
main.py
# This Python file uses the following encoding: utf-8
import os
# from pathlib import Path
import sys
import json
import requests
from PySide2.QtWidgets import QApplication
from PySide2.QtQml import QQmlApplicationEngine
from PySide2.QtCore import Slot, Signal, QObject
class MainWindow(QObject):
def __init__(self):
QObject.__init__(self)
signalcombo = Signal(str)
#Slot(str, str, str)
def add(self, getCombo):
putdata1 = {"category_name": getCombo}
data1 =
requests.post("random api", json=putdata1)
print(data1.text)
if __name__ == "__main__":
app = QApplication(sys.argv)
engine = QQmlApplicationEngine()
# engine.load(os.fspath(Path(__file__).resolve().parent / "qml/main.qml"))
engine.load(os.path.join(os.path.dirname(__file__), "qml/main.qml"))
# Get Context
main = MainWindow()
engine.rootContext().setContextProperty("backend", main)
if not engine.rootObjects():
sys.exit(-1)
sys.exit(app.exec_())
Now the problem is that when data1.text is printed it says "Inserted Successfully", but there is nothing in the database not even blank space. No data is being sent. Can anyone help me. This approach is working for textField but not for combobox.

Answer 1

There are various problems with your code.
First of all, the slot decorator for add has the wrong number of arguments. In the QML you're calling it with only one argument, but the slot has three. Change it to:
#Slot(str)
def add(self, getCombo):
# ...
Then, ComboBox has no property named text, but currentText (or any other valid property available for it, like displayText).
Button {
id: bt
width: 24
height: 24
onClicked: backend.add(comboBox.currentText)
}
Finally, while not critical, you should first set the context, and then load the QML:
main = MainWindow()
engine.rootContext().setContextProperty("backend", main)
engine.load(os.path.join(os.path.dirname(__file__), "qml/main.qml"))