ReferenceError: xxxx is not defined

Digitale_GFacchini

Hello,
why i have this error ?

qrc:/edit.qml:23: ReferenceError: edit_std_id is not defined

This is small code as an example

Window {
    id:testdbmodelview

    Connections {
        target: myModel // Specify the target connection
        onSendToQmlEdit: {
            edit_std_id.text = parseInt(idkeyrecord) // Set id record
        }
    }
    Item {
        id: formEdit
        width: 640
        height: 480

        Component {
            id: delegate
            Item {
                id: item_row_edit
                RowLayout {
                    id: row_id
                    Text {
                        id: lbl_id
                        text: qsTr("ID : ")
                    }
                    Rectangle {
                        id: rect_txt_id
                        width: 108
                        height: 28
                        radius: 1
                        TextInput {
                            id: edit_std_id
                            text: std_id
                            inputMask: qsTr("")
                        }
                    }
                }
            }
        }

        ListView {
            id: editfield
            height: 150
            contentHeight: 150
            anchors.top: rowHeader.bottom
            anchors.bottomMargin: 50
            model: myModelEdit
            delegate: delegate
        }
		. . . . 
    }
}

sierdzio

@Digitale_GFacchini said in ReferenceError: xxxx is not defined:

edit_std_id

This id is defined in a Component so it is a separate entity. QML engine treats it as if it was a separate QML file (so your current file has no access to ids from there, only to exposed properties if any.

Digitale_GFacchini

@sierdzio thaksthank you,
I suspected it.
I'm studying qt and c ++ recently. how can use , for example in a javascript or in evente clicked, edit_std_id.text?

sierdzio

@Digitale_GFacchini said in ReferenceError: xxxx is not defined:

. how can use , for example in a javascript or in evente clicked, edit_std_id.text?

In your case, where it's ListView that creates instances (objects) from your component, you can do something like:

editfield.currentItem.text = "blah blah"

But you need to add "text" property to your component. Probably this would work:

Component {
  Item {
    id: item_row_edit
    property alias text: edit_std_id.text

Or the property needs to be in Component, not item, I'm not sure.

Notice, however, that ListView can create and destroy your delegate objects at any time. It is much better to populate your delagate data from model. And if you need to modify that data (like text in your example), you should modify the model - ListView will automatically update. More info on models and views in QML: https://doc.qt.io/qt-5/qtquick-modelviewsdata-modelview.html

Digitale_GFacchini

@sierdzio hello, i have try use sistem with property alias.
If i put it between component and item

Component {
            id: delegate
            property alias aedit_std_id: edit_std_id.text
            Item {
                id: item_row_edit

In this mode component not load

If i put the row definition property after declare item so:

            Item {
                id: item_row_edit
                property alias aedit_std_id: edit_std_id.text

A have the original error: aedit_std_id is not defined

sierdzio

OK, then put your component in another QML file.

Digitale_GFacchini

@sierdzio hello, i have create a file MyDelagateFieldEdit

Item {
    id: rootDelegate
    RowLayout {
        id: row_id
        x: 7
        y: 9
        height: 36
        Text {
            id: lbl_id
            width: 120
            height: 20
            text: qsTr("ID : ")
            verticalAlignment: Text.AlignVCenter
            horizontalAlignment: Text.AlignRight
            font.pixelSize: 14
            Layout.fillWidth: false
            Layout.fillHeight: false
            Layout.minimumWidth: 120
            font.bold: true
        }
        Rectangle {
            id: rect_txt_id
            width: 108
            height: 28
            radius: 1
            border.width: 1
            border.color: "#a5aefa"
            anchors.leftMargin: 8
            anchors.left: lbl_id.right
            TextInput {
                id: edit_std_id
                height: 22
                text: std_id
                anchors.margins: 4
                font.pixelSize: 14
                cursorVisible: true
                antialiasing: true
                anchors.fill: parent
                clip: true
                inputMask: qsTr("")
                horizontalAlignment: Text.AlignRight
                verticalAlignment: Text.AlignVCenter
            }
        }
    }
    RowLayout  {
        id: row_nome
        parent: rootDelegate
        height: 36
        anchors.top: row_id.bottom
        anchors.topMargin: 6
        anchors.right: parent.right
        anchors.rightMargin: 20
        anchors.left: parent.left
        anchors.leftMargin: 20
        Text {
            id: lbl_nome
            width: 120
            height: 20
            text: qsTr("Nome : ")
            Layout.minimumWidth: 120
            Layout.fillHeight: false
            Layout.fillWidth: false
            font.bold: true
            horizontalAlignment: Text.AlignRight
            verticalAlignment: Text.AlignVCenter
            font.pixelSize: 14
        }
        Rectangle {
            id: rect_txt_nome
            width: 408
            height: 28
            border.width: 1
            border.color: "#a5aefa"
            radius: 2
            Layout.minimumWidth: 408
            anchors.left: lbl_nome.right
            anchors.leftMargin: 8
            TextInput {
                id: edit_std_nome
                width: 400
                height: 22
                text: std_nome
                anchors.margins: 4
                anchors.fill: parent
                antialiasing: true
                horizontalAlignment: Text.AlignLeft
                verticalAlignment: Text.AlignVCenter
                clip: true
                cursorVisible: true
                inputMask: qsTr("")
                font.pixelSize: 14
            }
        }
    }
    RowLayout {
        id: row_cognome
        parent: rootDelegate
        height: 36
        anchors.top: row_nome.bottom
        anchors.topMargin: 6
        anchors.right: parent.right
        anchors.rightMargin: 20
        anchors.left: parent.left
        anchors.leftMargin: 20
        Text {
            id: lbl_cognome
            width: 120
            height: 20
            text: qsTr("Cognome : ")
            Layout.minimumWidth: 120
            horizontalAlignment: Text.AlignRight
            verticalAlignment: Text.AlignVCenter
            font.bold: true
            font.pixelSize: 14
        }
        Rectangle {
                id: rect_txt_cognome
                width: 408
                height: 28
                border.width: 1
                border.color: "#a5aefa"
                radius: 4
                Layout.minimumWidth: 408
                anchors.left: lbl_cognome.right
                anchors.leftMargin: 8
            TextInput {
                id: edit_std_cognome
                width: 400
                height: 22
                text: std_cognome
                anchors.margins: 4
                anchors.fill: parent
                antialiasing: true
                horizontalAlignment: Text.AlignLeft
                verticalAlignment: Text.AlignVCenter
                clip: true
                cursorVisible: true
                font.pixelSize: 14
                inputMask: qsTr("")
            }
        }
    }
    RowLayout {
        id: row_luogonascita
        parent: rootDelegate
        height: 36
        anchors.right: parent.right
        anchors.rightMargin: 20
        anchors.left: parent.left
        anchors.leftMargin: 20
        anchors.top: row_cognome.bottom
        anchors.topMargin: 6
        anchors.bottomMargin: 25
        Text {
            id: lbl_luogonascita
            width: 120
            height: 20
            text: qsTr("Luogo Nascita : ")
            Layout.minimumWidth: 120
            horizontalAlignment: Text.AlignRight
            verticalAlignment: Text.AlignVCenter
            font.bold: true
            font.pixelSize: 14
        }
        Rectangle {
            id: rect_txt_luogonascita
            width: 408
            height: 28
            border.width: 1
            border.color: "#a5aefa"
            radius: 2
            Layout.minimumWidth: 408
            anchors.left: lbl_luogonascita.right
            anchors.leftMargin: 8
            TextInput {
                id: edit_std_luogonascita
                height: 22
                text: std_luogonascita
                anchors.margins: 4
                anchors.fill: parent
                antialiasing: true
                horizontalAlignment: Text.AlignLeft
                verticalAlignment: Text.AlignVCenter
                clip: true
                cursorVisible: true
                font.pixelSize: 14
                inputMask: qsTr("")
            }
        }
    }
}

In file edit.qml i have changed call delegate into ListView

        ListView {
            id: editfield
            height: 150
            contentHeight: 150
            anchors.top: rowHeader.bottom
            anchors.bottomMargin: 50
            model: myModelEdit
            delegate: MyDelagateFieldEdit {}
        }

Don't i have problem with data from model into every field into MyDelagateFieldEdit, for example "edit_std_id" or "edit_std_name", but when i want read data for update database I always have the same error.

ReferenceError: edit_std_nome is not defined

sierdzio

@Digitale_GFacchini said in ReferenceError: xxxx is not defined:

but when i want read data for update database I always have the same error.

where are you trying to read that data?

Digitale_GFacchini

@sierdzio when clicked button confirm in file edit.qml
I need to pass data to the function that will update the database

sierdzio

I mean where in code :-) Please paste the relevant piece of the code.

Digitale_GFacchini

@sierdzio hello, I stay try another way. if result ok i put solution. If not correct i public all code.

Digitale_GFacchini

@sierdzio Hello,
aving found no indication of how it can access from a file (edit.qml) to the values of the elements assigned in a delegate (MyDelagateFieldEdit.qml) I have applied the following method to read the data that are modified and then update the record.

http://imaginativethinking.ca/bi-directional-data-binding-qt-quick/bidirectionalbindingsample_1/

In my exercise program, however, I have only 3 fields to manage. I do not think it's the right way to handle data editing.

There is no one who has an example of a program with a list and management of data detail?
Yet it is a classic management program.

sierdzio

Here's some code that might help you https://doc.qt.io/qt-5/qtquick-modelviewsdata-cppmodels.html#qabstractitemmodel-subclass

Yet it is a classic management program.

Qt has no problem supporting that use case. It just requires some coding and getting used to. The model-view infrastructure is very flexible which also makes it a bit complex. Once you get to know it, though, it will be quite easy to work with.