DevExtreme Angular - Selection

User Interaction

In the List widget, selection is disabled by default. To enable it, choose one of selection modes using the selectionMode option.

jQuery
JavaScript
$(function() {
    $("#listContainer").dxList({
        // ...
        selectionMode: "single" // or "multiple" | "all" | "none" (disables selection)
    });
});
Angular
HTML
TypeScript
<dx-list ...
    selectionMode="single"> <!-- or "multiple" | "all" | "none" (disables selection) -->
</dx-list>
import { DxListModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

To select a List item, an end user simply clicks or taps it. Selected items become shaded. If you want to indicate selected items more manifestly, set the showSelectionControls option to true. This setting adds a check box to each item on the List. Also, make this setting if you use the "all" selectionMode. Otherwise, the "Select All" check box will be missing.

jQuery
JavaScript
$(function() {
    $("#listContainer").dxList({
        // ...
        showSelectionControls: true
    });
});
Angular
HTML
TypeScript
<dx-list ...
    [showSelectionControls]="true"> 
</dx-list>
import { DxListModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

When data in the List is paginated, you can choose whether the "Select All" check box will select all items on all pages or items on the currently rendered pages only. To make this choice, specify the selectAllMode option.

jQuery
JavaScript
$(function() {
    $("#listContainer").dxList({
        // ...
        selectAllMode: "allPages" // or "page"
    });
});
Angular
HTML
TypeScript
<dx-list ...
    selectAllMode="allPages"> <!-- or "page" -->
</dx-list>
import { DxListModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

View Demo

See Also

API

You can select an item or cancel its selection in the following ways.

  • By key
    Add or remove the key from the selectedItemKeys collection.

    jQuery
    JavaScript
    var list = $("#listContainer").dxList("instance");
var selectedKeys = list.option("selectedItemKeys");
// Selects the item with key 5
selectedKeys.push(5);
list.option("selectedItemKeys", selectedKeys);
// Cancels the selection of the item with key 5
selectedKeys = $.grep(selectedKeys, function(key) {
    return key != 5;
});
list.option("selectedItemKeys", selectedKeys);
    Angular
    TypeScript
    import { ..., ViewChild } from "@angular/core";
import { DxListModule, DxListComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxListComponent, { static: false }) list: DxListComponent;
    // Prior to Angular 8
    // @ViewChild(DxListComponent) list: DxListComponent;
    selectItem (key) {
        let selectedKeys = this.list.instance.option("selectedItemKeys");
        if(selectedKeys.includes(key)) {
            // Cancels the selection of the item with the key
            selectedKeys = selectedKeys.filter((data) => {
                return data != key;
            });
        } else {
            // Selects the item with the key
            selectedKeys.push(key);
        }
        this.list.instance.option("selectedItemKeys", selectedKeys);
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

    You can also use the selectedItemKeys collection to select items initially.

    jQuery
    JavaScript
    $(function() {
    $("#listContainer").dxList({
        // ...
        selectedItemKeys: [0, 2, 5]
    });
});
    Angular
    HTML
    TypeScript
    <dx-list ...
    [selectedItemKeys]="[0, 2, 5]">
</dx-list>
    import { DxListModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})
    NOTE
    To specify the key field, use the keyExpr option of the List or the key option of the Store.

  • By data object
    Add or remove the data object from the selectedItems collection.

    jQuery
    JavaScript
    var fruits = [
    { fruit: "Apples", count: 10 },
    { fruit: "Oranges", count: 12 },
    { fruit: "Lemons", count: 15 }
];
var list = $("#listContainer").dxList("instance");
var selectedItems = list.option("selectedItems");
// Selects the "Oranges" item
selectedItems.push(fruits[1]);
list.option("selectedItems", selectedItems);
// Cancels the selection of the "Oranges" item
selectedItems = $.grep(selectedItems, function(item) {
    return item != fruits[1];
});
list.option("selectedItems", selectedItems);
    Angular
    TypeScript
    import { ..., ViewChild } from "@angular/core";
import { DxListModule, DxListComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxListComponent, { static: false }) list: DxListComponent;
    // Prior to Angular 8
    // @ViewChild(DxListComponent) list: DxListComponent;
    fruits = [
        { fruit: "Apples", count: 10 },
        { fruit: "Oranges", count: 12 },
        { fruit: "Lemons", count: 15 }
    ];
    selectOranges () {
        let selectedItems = this.list.instance.option("selectedItems");
        selectedItems.push(fruits[1]);
        this.list.instance.option("selectedItems", selectedItems);
    }
    unselectOranges () {
        let selectedItems = this.list.instance.option("selectedItems");
        selectedItems = selectedItems.filter((item) => {
            return item != fruits[1];
        });
        this.list.instance.option("selectedItems", selectedItems);
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

    You can also use the selectedItems collection to select items initially.

    jQuery
    JavaScript
    var fruits = [
    // ...
];
$(function() {
    $("#listContainer").dxList({
        dataSource: fruits,
        selectedItems: [fruits[0], fruits[2]]
    });
});
    Angular
    HTML
    TypeScript
    <dx-list ...
    [dataSource]="fruits"
    [selectedItems]="[fruits[0], fruits[2]]">
</dx-list>
    import { DxListModule } from "devextreme-angular";
// ...
export class AppComponent {
    fruits = [
        // ...
    ]
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

  • By index
    Pass the index to the selectItem(itemIndex) or unselectItem(itemIndex) method. If the List is grouped, these methods should be given an object with the indexes of the group and the item.

    jQuery
    JavaScript
    var list = $("#listContainer").dxList("instance");
// Selects the item with index 1
list.selectItem(1);
// Checks that the item with index 1 is selected; if so, cancels the selection
if(list.isItemSelected(1)) {
    list.unselectItem(1);
}
// Selects the item with index 3 in the group with index 2
list.selectItem({ group: 2, item: 3 });
// Checks that the item with index 3 in the group with index 2 is selected; if so, cancels the selection
var itemToUnselect = { group: 2, item: 3 };
if(list.isItemSelected(itemToUnselect)) {
    list.unselectItem(itemToUnselect);
}
    Angular
    TypeScript
    import { ..., ViewChild } from "@angular/core";
import { DxListModule, DxListComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxListComponent, { static: false }) list: DxListComponent;
    // Prior to Angular 8
    // @ViewChild(DxListComponent) list: DxListComponent;
    selectItem (index) {
        // Checks that the item with the index is selected
        if (this.list.isItemSelected(index)) {
            // If the item is selected, clears its selection
            this.list.instance.unselectItem(index);
        } else {
            // If the item is not selected, selects it
            this.list.instance.selectItem(index);
        }
    }
    selectItemInGroup (groupIndex, itemIndex) {
        let item = { group: groupIndex, item: itemIndex };
        // Checks that the item is selected
        if(this.list.instance.isItemSelected(item)) {
            // If the item is selected, clears its selection
            this.list.instance.unselectItem(item);
        } else {
            // If the item is not selected, selects it
            this.list.instance.selectItem(item);
        }
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

  • By DOM node
    Pass the DOM node to the selectItem(itemElement) or unselectItem(itemElement) method.

    jQuery
    JavaScript
    var list = $("#listContainer").dxList("instance");
var itemNodes = $("#listContainer").find(".dx-list-item");
// Selects the last item by its DOM node
list.selectItem(itemNodes[itemNodes.length-1]);
// Checks that the last item is selected; if so, cancels the selection
if(list.isItemSelected(itemNodes[itemNodes.length-1])) {
    list.unselectItem(itemNodes[itemNodes.length-1]);
}
    Angular
    TypeScript
    import { ..., ViewChild } from "@angular/core";
import { DxListModule, DxListComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxListComponent, { static: false }) list: DxListComponent;
    // Prior to Angular 8
    // @ViewChild(DxListComponent) list: DxListComponent;
    selectLastItem () {
        var itemNodes = document.getElementsByClassName("dx-list-item");
        // Selects the last item by its DOM node
        this.list.instance.selectItem(itemNodes[itemNodes.length-1]);
    }
    unselectLastItem () {
        var itemNodes = document.getElementsByClassName("dx-list-item");
        // Checks that the last item is selected; if so, cancels the selection
        if(this.list.instance.isItemSelected(itemNodes[itemNodes.length-1])) {
            this.list.instance.unselectItem(itemNodes[itemNodes.length-1]);
        }
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})
See Also

Events

The List widget fires the selectionChanged event when an item is selected or when the selection is cancelled. The widget also fires the selectAllValueChanged event when the "Select All" check box has changed its value. If the functions that handle these events are not going to be changed during the lifetime of the widget, assign them to the corresponding onEventName options when you configure the widget.

jQuery
JavaScript
$(function () {
    $("#listContainer").dxList({
        // ...
        onSelectionChanged: function(e) {
            var addedItems = e.addedItems;
            var removedItems = e.removedItems;
            // Handler of the "selectionChanged" event
        },
        onSelectAllValueChanged: function(e) {
            var newCheckBoxValue = e.value;
            // Handler of the "selectAllValueChanged" event
        }
    });
});
Angular
HTML
TypeScript
<dx-list ...
    (onSelectionChanged)="onSelectionChanged($event)"
    (onSelectAllValueChanged)="onSelectAllValueChanged($event)">
</dx-list>
import { DxListModule } from "devextreme-angular";
// ...
export class AppComponent {
    onSelectionChanged (e) {
        let addedItems = e.addedItems;
        let removedItems = e.removedItems;
        // Handler of the "selectionChanged" event
    }
    onSelectAllValueChanged (e) {
        let newCheckBoxValue = e.value;
        // Handler of the "selectAllValueChanged" event
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})

View Demo

If you are going to change the event handlers at runtime, or if you need to attach several handlers to a single event, subscribe to this event using the on(eventName, eventHandler) method. This approach is more typical of jQuery.

JavaScript
var selectionChangedEventHandler1 = function(e) {
    // First handler of the "selectionChanged" event
};

var selectionChangedEventHandler2 = function(e) {
    // Second handler of the "selectionChanged" event
};

$("#listContainer").dxList("instance")
    .on("selectionChanged", selectionChangedEventHandler1)
    .on("selectionChanged", selectionChangedEventHandler2);
See Also