DevExtreme Angular - LocalStore API

The LocalStore is a store that provides an interface for loading and editing data from HTML Web Storage (also known as window.localStorage) and handling related events.

import LocalStore from "devextreme/data/local_store"

When configuring the LocalStore, specify the name under which data should be saved in the browser's localStorage object.

jQuery
JavaScript
var states = [
    { id: 1, state: "Alabama", capital: "Montgomery" },
    { id: 2, state: "Alaska", capital: "Juneau" },
    { id: 3, state: "Arizona", capital: "Phoenix" },
    // ...
];

var store = new DevExpress.data.LocalStore({
    key: "id",
    data: states,
    name: "myLocalData",
    // Other LocalStore properties go here
});

// ===== or inside the DataSource =====
var dataSource = new DevExpress.data.DataSource({
    store: {
        type: "local",
        key: "id",
        data: states,
        name: "myLocalData",
        // Other LocalStore properties go here
    },
    // Other DataSource properties go here
});
Angular
TypeScript
import LocalStore from "devextreme/data/local_store";
import DataSource from "devextreme/data/data_source";
// ...
export class AppComponent {
    store: LocalStore;
    dataSource: DataSource;
    states = [
        { id: 1, state: "Alabama", capital: "Montgomery" },
        { id: 2, state: "Alaska", capital: "Juneau" },
        { id: 3, state: "Arizona", capital: "Phoenix" },
        // ...
    ];
    constructor () {
        this.store = new LocalStore({
            key: "id",
            data: this.states,
            name: "myLocalData",
            // Other LocalStore properties go here
        });

        // ===== or inside the DataSource =====
        this.dataSource = new DataSource({
            store: new LocalStore({
                key: "id",
                data: this.states,
                name: "myLocalData",
                // Other LocalStore properties go here
            }),
            // Other DataSource properties go here
        });
    }
}
AngularJS
JavaScript
angular.module('DemoApp', ['dx'])
    .controller('DemoController', function DemoController($scope) {
        var states = [
            { id: 1, state: "Alabama", capital: "Montgomery" },
            { id: 2, state: "Alaska", capital: "Juneau" },
            { id: 3, state: "Arizona", capital: "Phoenix" },
            // ...
        ];
        $scope.store = new DevExpress.data.LocalStore({
            key: "id",
            data: states,
            name: "myLocalData",
            // Other LocalStore properties go here
        });

        // ===== or inside the DataSource =====
        $scope.dataSource = new DevExpress.data.DataSource({
            store: {
                type: "local",
                key: "id",
                data: states,
                name: "myLocalData",
                // Other LocalStore properties go here
            },
            // Other DataSource properties go here
        });
    });
Knockout
JavaScript
var states = [
    { id: 1, state: "Alabama", capital: "Montgomery" },
    { id: 2, state: "Alaska", capital: "Juneau" },
    { id: 3, state: "Arizona", capital: "Phoenix" },
    // ...
];

var viewModel = {
    store: new DevExpress.data.LocalStore({
        key: "id",
        data: states,
        name: "myLocalData",
        // Other LocalStore properties go here
    })

    // ===== or inside the DataSource =====
    dataSource: new DevExpress.data.DataSource({
        store: {
            type: "local",
            key: "id",
            data: states,
            name: "myLocalData",
            // Other LocalStore properties go here
        },
        // Other DataSource properties go here
    })
};

ko.applyBindings(viewModel);
Vue
App.vue
<script>
import LocalStore from 'devextreme/data/local_store';
import DataSource from 'devextreme/data/data_source';

const states = [
    { id: 1, state: 'Alabama', capital: 'Montgomery' },
    { id: 2, state: 'Alaska', capital: 'Juneau' },
    { id: 3, state: 'Arizona', capital: 'Phoenix' },
    // ...
];

const store = new LocalStore({
    key: 'id',
    data: states,
    name: 'myLocalData',
    // Other LocalStore properties go here
});

// ===== or inside the DataSource =====
const dataSource = new DataSource({
    store: new LocalStore({
        key: 'id',
        data: states,
        name: 'myLocalData',
        // Other LocalStore properties go here
    }),
    // Other DataSource properties go here
});

export default {
    // ...
    data() {
        return {
            store,
            // ===== or =====
            dataSource
        }
    }
}
</script>
React
App.js
// ...
import LocalStore from 'devextreme/data/local_store';
import DataSource from 'devextreme/data/data_source';

const states = [
    { id: 1, state: 'Alabama', capital: 'Montgomery' },
    { id: 2, state: 'Alaska', capital: 'Juneau' },
    { id: 3, state: 'Arizona', capital: 'Phoenix' },
    // ...
];

const store = new LocalStore({
    key: 'id',
    data: states,
    name: 'myLocalData',
    // Other LocalStore properties go here
});

// ===== or inside the DataSource =====
const dataSource = new DataSource({
    store: new LocalStore({
        key: 'id',
        data: states,
        name: 'myLocalData',
        // Other LocalStore properties go here
    }),
    // Other DataSource properties go here
});

class App extends React.Component {
    // ...
}
export default App;
NOTE
The LocalStore is immutable. You cannot change its configuration at runtime. However, you can use its methods to manipulate it.
See Also

Configuration

This section describes properties that configure the LocalStore.

Name Description
data

Specifies the store's associated array.
errorHandler

Specifies the function that is executed when the store throws an error.
flushInterval

Specifies a delay in milliseconds between when data changes and the moment these changes are saved in the local storage. Applies only if immediate is false.
immediate

Specifies whether the LocalStore saves changes in the local storage immediately.
key

Specifies the key property (or properties) that provide(s) key values to access data items. Each key value must be unique.
name

Specifies the name under which data should be saved in the local storage. The dx-data-localStore- prefix will be added to the name.
onInserted

A function that is executed after a data item is added to the store.
onInserting

A function that is executed before a data item is added to the store.
onLoaded

A function that is executed after data is loaded to the store.
onLoading

A function that is executed before data is loaded to the store.
onModified

A function that is executed after a data item is added, updated, or removed from the store.
onModifying

A function that is executed before a data item is added, updated, or removed from the store.
onPush

The function executed before changes are pushed to the store.
onRemoved

A function that is executed after a data item is removed from the store.
onRemoving

A function that is executed before a data item is removed from the store.
onUpdated

A function that is executed after a data item is updated in the store.
onUpdating

A function that is executed before a data item is updated in the store.

Methods

This section describes methods that control the LocalStore.

Name Description
byKey(key)

Gets a data item with a specific key.
clear()

Removes data from the local storage.
createQuery()

Creates a Query for the underlying array.
insert(values)

Adds a data item to the store.
key()

Gets the key property (or properties) as specified in the key property.
keyOf(obj)

Gets a data item's key value.
load()

Starts loading data.
load(options)

Starts loading data.
off(eventName)

Detaches all event handlers from a single event.
off(eventName, eventHandler)

Detaches a particular event handler from a single event.
on(eventName, eventHandler)

Subscribes to an event.
on(events)

Subscribes to events.
push(changes)

Pushes data changes to the store and notifies the DataSource.
remove(key)

Removes a data item with a specific key from the store.
totalCount(options)

Gets the total count of items the load() function returns.
update(key, values)

Updates a data item with a specific key.

Events

This section describes events that the LocalStore raises.

Name Description
inserted

Raised after a data item is added to the store.
inserting

Raised before a data item is added to the store.
loaded

Raised after data is loaded to the store.
loading

Raised before data is loaded to the store.
modified

Raised after a data item is added, updated, or removed from the store.
modifying

Raised before a data item is added, updated, or removed from the store.
push

Raised before changes are pushed to the store.
removed

Raised after a data item is removed from the store.
removing

Raised before a data item is removed from the store.
updated

Raised after a data item is updated in the store.
updating

Raised before a data item is updated in the store.