JavaScript/jQuery Lookup Methods
This section describes the methods that control the Lookup UI component.
beginUpdate()
Prevents the UI component from refreshing until the endUpdate() method is called.
The beginUpdate() and endUpdate() methods prevent the UI component from excessive updates when you are changing multiple UI component settings at once. After the beginUpdate() method is called, the UI component does not update its UI until the endUpdate() method is called.
See Also
content()
Gets the popup window's content.
An HTML element or a jQuery element when you use jQuery.
defaultOptions(rule)
Specifies the device-dependent default configuration properties for this component.
The component's default device properties.
defaultOptions is a static method that the UI component class supports. The following code demonstrates how to specify default properties for all instances of the Lookup UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxLookup.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Lookup properties } });
Angular
import Lookup from "devextreme/ui/lookup"; // ... export class AppComponent { constructor () { Lookup.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Lookup properties } }); } }
Vue
<template> <div> <DxLookup id="lookup1" /> <DxLookup id="lookup2" /> </div> </template> <script> import DxLookup from "devextreme-vue/lookup"; import Lookup from "devextreme/ui/lookup"; Lookup.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Lookup properties } }); export default { components: { DxLookup } } </script>
React
import React, {useEffect} from "react"; import dxLookup from "devextreme/ui/lookup"; import Lookup from "devextreme-react/lookup"; export default function App() { useEffect(() => { dxLookup.defaultOptions({ device: { deviceType: "desktop" }, options: { // Here go the Lookup properties } }) }); return ( <div> <Lookup id="lookup1" /> <Lookup id="lookup2" /> </div> ) }
dispose()
Disposes of all the resources allocated to the Lookup instance.
After calling this method, remove the DOM element associated with the UI component:
$("#myLookup").dxLookup("dispose"); $("#myLookup").remove();
Use this method only if the UI component was created with jQuery or pure JavaScript. In Angular, Vue, and React, use conditional rendering:
Angular
<dx-lookup ... *ngIf="condition"> </dx-lookup>
Vue
<template> <DxLookup ... v-if="condition"> </DxLookup> </template> <script> import DxLookup from 'devextreme-vue/lookup'; export default { components: { DxLookup } } </script>
React
import React from 'react'; import Lookup from 'devextreme-react/lookup'; function DxLookup(props) { if (!props.shouldRender) { return null; } return ( <Lookup ... > </Lookup> ); } class App extends React.Component { render() { return ( <DxLookup shouldRender="condition" /> ); } } export default App;
See Also
element()
Gets the root UI component element.
An HTML element or a jQuery element when you use jQuery.
field()
Gets the UI component's <input>
element.
An HTML element or a jQuery element when you use jQuery.
getDataSource()
Gets the DataSource instance.
The DataSource instance.
See Also
- Call Methods: Angular | Vue | React | jQuery | AngularJS | Knockout
- Data Layer - Overview
- Data Layer - DataSource Examples
getInstance(element)
Gets the instance of a UI component found using its DOM node.
The UI component's instance.
getInstance is a static method that the UI component class supports. The following code demonstrates how to get the Lookup instance found in an element with the myLookup
ID:
// Modular approach import Lookup from "devextreme/ui/lookup"; ... let element = document.getElementById("myLookup"); let instance = Lookup.getInstance(element) as Lookup; // Non-modular approach let element = document.getElementById("myLookup"); let instance = DevExpress.ui.dxLookup.getInstance(element);
See Also
instance()
Gets the UI component's instance. Use it to access other methods of the UI component.
This UI component's instance.
off(eventName)
Detaches all event handlers from a single event.
The event's name.
The object for which this method is called.
off(eventName, eventHandler)
Detaches a particular event handler from a single event.
The object for which this method is called.
on(eventName, eventHandler)
Subscribes to an event.
The object for which this method is called.
on(events)
Subscribes to events.
Events with their handlers: { "eventName1": handler1, "eventName2": handler2, ...}
The object for which this method is called.
option(optionName)
Gets the value of a single property.
The property's name or full path.
This property's value.
option(options)
Updates the values of several properties.
Options with their new values.
registerKeyHandler(key, handler)
Registers a handler to be executed when a user presses a specific key.
A key.
A handler. Accepts the keydown event as the argument. It is a dxEvent or a jQuery.Event when you use jQuery.
The key argument accepts one of the following values:
- "backspace"
- "tab"
- "enter"
- "escape"
- "pageUp"
- "pageDown"
- "end"
- "home"
- "leftArrow"
- "upArrow"
- "rightArrow"
- "downArrow"
- "del"
- "space"
- "F"
- "A"
- "asterisk"
- "minus"
A custom handler for a key cancels the default handler for this key.
See Also
repaint()
Repaints the UI component without reloading data. Call it to update the UI component's markup.
resetOption(optionName)
Resets a property to its default value.
A property's name.
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