DevExtreme jQuery/JS - Configure Search Parameters

NOTE
Searching works when inputting a plain data structure only. However, if you need the searching capability and hierarchical data, transform the plain data using the DataSource's group option.

The Lookup widget allows a user to search through its items. Moreover, the widget offers suggestions while the user types a value into the search box. Usually, the data field that provides suggestions is the same data field that is searched for the typed value. If there are two different fields, assign the field providing suggestions to the valueExpr option and the field to be searched to the searchExpr option. Assign an array of field names to the searchExpr option if you need to search several fields.

jQuery
JavaScript
var lookupData = [
    { country: "Afghanistan", capital: "Kabul" },
    { country: "Albania", capital: "Tirana" },
    // ...
];

$(function() {
    $("#lookupContainer").dxLookup({
        dataSource: lookupData,
        valueExpr: 'country',
        displayExpr: 'country',
        searchExpr: 'capital',
        placeholder: 'Select country'
    });
});
Angular
HTML
TypeScript
<dx-lookup
    [dataSource]="lookupDataSource"
    valueExpr="country"
    displayExpr="country"
    searchExpr="capital"
    placeholder="Select country">
</dx-lookup>
import { DxLookupModule } from "devextreme-angular";
// ...
export class AppComponent {
    lookupDataSource = [
        { country: "Afghanistan", capital: "Kabul" },
        { country: "Albania", capital: "Tirana" },
        // ...
    ];
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})

The Lookup widget can provide suggestions in two different modes: 'contains' (by default) and 'startswith'. You can use the searchMode option to change the mode. You can also use the searchPlaceholder option to specify a placeholder for an empty search box.

jQuery
JavaScript
var lookupData = [
    { country: "Afghanistan", capital: "Kabul" },
    { country: "Albania", capital: "Tirana" },
    // ...
];

$(function() {
    $("#lookupContainer").dxLookup({
        dataSource: lookupData,
        valueExpr: 'country',
        displayExpr: 'country',
        searchMode: 'startswith',
        searchPlaceholder: 'Type country name'
    });
});
Angular
HTML
TypeScript
<dx-lookup
    [dataSource]="lookupDataSource"
    valueExpr="country"
    displayExpr="country"
    searchMode="startswith"
    searchPlaceholder="Type country name">
</dx-lookup>
import { DxLookupModule } from "devextreme-angular";
// ...
export class AppComponent {
    lookupDataSource = [
        { country: "Afghanistan", capital: "Kabul" },
        { country: "Albania", capital: "Tirana" },
        // ...
    ];
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})

The Lookup widget starts providing suggestions once an end user types the first character by default. Use the minSearchLength option to increase the number of characters that triggers suggestions.

jQuery
JavaScript
$(function() {
    $("#lookupContainer").dxLookup({
        // ...
        minSearchLength: 3
    });
});
Angular
HTML
TypeScript
<dx-lookup ...
    [minSearchLength]="3">
</dx-lookup>
import { DxLookupModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})

There is a delay between the moment a user finishes typing and the moment the Lookup starts providing suggestions. To increase or descrease it, use the searchTimeout option. The delay is measured in milliseconds.

jQuery
JavaScript
$(function() {
    $("#lookupContainer").dxLookup({
        // ...
        searchTimeout: 500
    });
});
Angular
HTML
TypeScript
<dx-lookup ...
    [searchTimeout]="500">
</dx-lookup>
import { DxLookupModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})

The Lookup widget also clears previous search results before the drop-down menu is displayed by default. Assign false to the cleanSearchOnOpening option to keep them.

jQuery
JavaScript
$(function() {
    $("#lookupContainer").dxLookup({
        // ...
        cleanSearchOnOpening: false
    });
});
Angular
HTML
TypeScript
<dx-lookup ...
    [cleanSearchOnOpening]="false">
</dx-lookup>
import { DxLookupModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})

Assign false to the searchEnabled option if you need to disable searching.

jQuery
JavaScript
$(function() {
    $("#lookupContainer").dxLookup({
        // ...
        searchEnabled: false
    });
});
Angular
HTML
TypeScript
<dx-lookup ...
    [searchEnabled]="false">
</dx-lookup>
import { DxLookupModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxLookupModule
    ],
    // ...
})
See Also