TableModel QML Type

Encapsulates a simple table model. More...

• List of all members, including inherited members

Properties

• columnCount : int
• rowCount : int
• rows : object

Methods

• appendRow(object row)
• clear()
• variant data(QModelIndex index, string role)
• object getRow(int rowIndex)
• QModelIndex index(int row, int column)
• insertRow(int rowIndex, object row)
• moveRow(int fromRowIndex, int toRowIndex, int rows)
• removeRow(int rowIndex, int rows)
• bool setData(QModelIndex index, string role, variant value)
• setRow(int rowIndex, object row)

Detailed Description

The TableModel type stores JavaScript/JSON objects as data for a table model that can be used with TableView. It is intended to support very simple models without requiring the creation of a custom QAbstractTableModel subclass in C++.

 import QtQuick 2.12
 import QtQuick.Window 2.12
 import Qt.labs.qmlmodels 1.0

 Window {
     width: 400
     height: 400
     visible: true

     TableView {
         anchors.fill: parent
         columnSpacing: 1
         rowSpacing: 1
         boundsBehavior: Flickable.StopAtBounds

         model: TableModel {
             TableModelColumn { display: "checked" }
             TableModelColumn { display: "amount" }
             TableModelColumn { display: "fruitType" }
             TableModelColumn { display: "fruitName" }
             TableModelColumn { display: "fruitPrice" }

             // Each row is one type of fruit that can be ordered
             rows: [
                 {
                     // Each property is one cell/column.
                     checked: false,
                     amount: 1,
                     fruitType: "Apple",
                     fruitName: "Granny Smith",
                     fruitPrice: 1.50
                 },
                 {
                     checked: true,
                     amount: 4,
                     fruitType: "Orange",
                     fruitName: "Navel",
                     fruitPrice: 2.50
                 },
                 {
                     checked: false,
                     amount: 1,
                     fruitType: "Banana",
                     fruitName: "Cavendish",
                     fruitPrice: 3.50
                 }
             ]
         }
         delegate:  TextInput {
             text: model.display
             padding: 12
             selectByMouse: true

             onAccepted: model.display = text

             Rectangle {
                 anchors.fill: parent
                 color: "#efefef"
                 z: -1
             }
         }
     }
 }

The model's initial row data is set with either the rows property or by calling appendRow(). Each column in the model is specified by declaring a TableModelColumn instance, where the order of each instance determines its column index. Once the model's Component::completed() signal has been emitted, the columns and roles will have been established and are then fixed for the lifetime of the model.

To access a specific row, the getRow() function can be used. It's also possible to access the model's JavaScript data directly via the rows property, but it is not possible to modify the model data this way.

To add new rows, use appendRow() and insertRow(). To modify existing rows, use setRow(), moveRow(), removeRow(), and clear().

It is also possible to modify the model's data via the delegate, as shown in the example above:

         delegate:  TextInput {
             text: model.display
             padding: 12
             selectByMouse: true

             onAccepted: model.display = text

             Rectangle {
                 anchors.fill: parent
                 color: "#efefef"
                 z: -1
             }
         }

If the type of the data at the modified role does not match the type of the data that is set, it will be automatically converted via QVariant.

Supported Row Data Structures

TableModel is designed to work with JavaScript/JSON data, where each row is a simple key-pair object:

 {
     // Each property is one cell/column.
     checked: false,
     amount: 1,
     fruitType: "Apple",
     fruitName: "Granny Smith",
     fruitPrice: 1.50
 },
 // ...

As model manipulation in Qt is done via row and column indices, and because object keys are unordered, each column must be specified via TableModelColumn. This allows mapping Qt's built-in roles to any property in each row object.

Complex row structures are supported, but with limited functionality. As TableModel has no way of knowing how each row is structured, it cannot manipulate it. As a consequence of this, the copy of the model data that TableModel has stored in rows is not kept in sync with the source data that was set in QML. For these reasons, TableModel relies on the user to handle simple data manipulation.

For example, suppose you wanted to have several roles per column. One way of doing this is to use a data source where each row is an array and each cell is an object. To use this data source with TableModel, define a getter and setter:

 TableModel {
     TableModelColumn {
         display: function(modelIndex) { return rows[modelIndex.row][0].checked }
         setDisplay: function(modelIndex, cellData) { rows[modelIndex.row][0].checked = cellData }
     }
     // ...

     rows: [
         [
             { checked: false, checkable: true },
             { amount: 1 },
             { fruitType: "Apple" },
             { fruitName: "Granny Smith" },
             { fruitPrice: 1.50 }
         ]
         // ...
     ]
 }

The row above is one example of a complex row.

Using DelegateChooser with TableModel

For most real world use cases, it is recommended to use DelegateChooser as the delegate of a TableView that uses TableModel. This allows you to use specific roles in the relevant delegates. For example, the snippet above can be rewritten to use DelegateChooser like so:

 import QtQuick 2.12
 import QtQuick.Controls 2.5
 import Qt.labs.qmlmodels 1.0

 ApplicationWindow {
     width: 400
     height: 400
     visible: true

     TableView {
         anchors.fill: parent
         columnSpacing: 1
         rowSpacing: 1
         boundsBehavior: Flickable.StopAtBounds

         model: TableModel {
             TableModelColumn { display: "checked" }
             TableModelColumn { display: "amount" }
             TableModelColumn { display: "fruitType" }
             TableModelColumn { display: "fruitName" }
             TableModelColumn { display: "fruitPrice" }

             // Each row is one type of fruit that can be ordered
             rows: [
                 {
                     // Each property is one cell/column.
                     checked: false,
                     amount: 1,
                     fruitType: "Apple",
                     fruitName: "Granny Smith",
                     fruitPrice: 1.50
                 },
                 {
                     checked: true,
                     amount: 4,
                     fruitType: "Orange",
                     fruitName: "Navel",
                     fruitPrice: 2.50
                 },
                 {
                     checked: false,
                     amount: 1,
                     fruitType: "Banana",
                     fruitName: "Cavendish",
                     fruitPrice: 3.50
                 }
             ]
         }
         delegate: DelegateChooser {
             DelegateChoice {
                 column: 0
                 delegate: CheckBox {
                     checked: model.display
                     onToggled: model.display = checked
                 }
             }
             DelegateChoice {
                 column: 1
                 delegate: SpinBox {
                     value: model.display
                     onValueModified: model.display = value
                 }
             }
             DelegateChoice {
                 delegate: TextField {
                     text: model.display
                     selectByMouse: true
                     implicitWidth: 140
                     onAccepted: model.display = text
                 }
             }
         }
     }
 }

The most specific delegates are declared first: the columns at index 0 and 1 have bool and integer data types, so they use a CheckBox and SpinBox, respectively. The remaining columns can simply use a TextField, and so that delegate is declared last as a fallback.

See also TableModelColumn, TableView, and QAbstractTableModel.

Property Documentation

             rows: [
                 {
                     // Each property is one cell/column.
                     checked: false,
                     amount: 1,
                     fruitType: "Apple",
                     fruitName: "Granny Smith",
                     fruitPrice: 1.50
                 },
                 {
                     checked: true,
                     amount: 4,
                     fruitType: "Orange",
                     fruitName: "Navel",
                     fruitPrice: 2.50
                 },
                 {
                     checked: false,
                     amount: 1,
                     fruitType: "Banana",
                     fruitName: "Cavendish",
                     fruitPrice: 3.50
                 }
             ]

Method Documentation

 model.appendRow({
     checkable: true,
     amount: 1,
     fruitType: "Pear",
     fruitName: "Williams",
     fruitPrice: 1.50,
 })

 Component.onCompleted: {
     // These two lines are equivalent.
     console.log(model.getRow(0).display);
     console.log(model.rows[0].fruitName);
 }

 import QtQml 2.14
 import Qt.labs.qmlmodels 1.0

 TableModel {
     id: model

     TableModelColumn { display: "fruitType" }
     TableModelColumn { display: "fruitPrice" }

     rows: [
         { fruitType: "Apple", fruitPrice: 1.50 },
         { fruitType: "Orange", fruitPrice: 2.50 }
     ]

     Component.onCompleted: {
         for (var r = 0; r < model.rowCount; ++r) {
             console.log("An " + model.data(model.index(r, 0)).display +
                         " costs " + model.data(model.index(r, 1)).display.toFixed(2))
         }
     }
 }

 model.insertRow(2, {
     checkable: true, checked: false,
     amount: 1,
     fruitType: "Pear",
     fruitName: "Williams",
     fruitPrice: 1.50,
 })

 model.moveRow(0, model.rowCount - 3, 3)

 model.setRow(0, {
     checkable: true,
     amount: 1,
     fruitType: "Pear",
     fruitName: "Williams",
     fruitPrice: 1.50,
 })