QML Dynamically Update ListModel - qt

Question

I'm confused at some point in QML as I'm new to it. The simplified QML codes define a window that includes one ListView which includes my delegate Items. One button loads and unloads this ListView Element. When I load and unload the ListView Element, all text that I wrote inside the TextInput is reset from listModel as I expected. So I need to dynamically update listModel thus I will not lose the text that I wrote in TextInput. I added a Keys.onPressed in TextInput to achieve that. But it works with some logical error. When I type, let's say "aaaa", then I unload the ListView and load again via Button, what I get is "aaa" (the last letter is not passed to listModel). This is understandable but how can I update the list model roles dynamically in this example?
main.qml
ApplicationWindow {
id: applicationWindow
width: 300
height: 200
visible: true
title: qsTr("01_Change_Model_Data")
ListModel {
id: listModel1
ListElement {labelText: "Text Field 1:"; textInput_text : "This is text 1"}
ListElement {labelText: "Text Field 2:"; textInput_text : "This is text 2"}
}
Button {
id: loadUnloadBtn
height: 24
width: 50
text: "Load"
anchors {
right: parent.right
rightMargin: 20
top: parent.top
topMargin: 10
}
onClicked: {
if(listAreaLoader.source == "") {
listAreaLoader.source = "ListArea.qml"
}else {
listAreaLoader.source = ""
}
}
}
Loader {
id: listAreaLoader
anchors {
top: parent.top
topMargin: 10
bottom: parent.bottom
bottomMargin: 10
left: parent.left
leftMargin: 10
right: parent.right
rightMargin: 80
}
source: ""
}
}
ListArea.qml:
Item {
id: listViewDelegate
ListView {
id: listView1
anchors.fill: parent
model: listModel1
delegate: listElementDelegate
spacing: 6
}
Component {
id: listElementDelegate
Rectangle {
color: "#00000000"
height: 24
width: 50
Label {
id: label1
text: labelText
}
Rectangle {
color: "grey"
radius: 4
width: 100
height: 20
anchors {
verticalCenter: label1.verticalCenter
left: label1.right
leftMargin: 10
}
TextInput {
id: textInput1
anchors.fill: parent
leftPadding: 5
rightPadding: 5
clip: true
verticalAlignment: Text.AlignVCenter
text: textInput_text
Keys.onPressed: {
listView1.currentIndex = index
listModel1.setProperty(index, "textInput_text", textInput1.text)
}
}
}
}
}
}