JavaScript/jQuery ScrollView Methods
beginUpdate()
Postpones rendering that can negatively affect performance until the endUpdate() method is called.
The beginUpdate() and endUpdate() methods reduce the number of renders in cases where extra rendering can negatively affect performance.
See Also
defaultOptions(rule)
| Name | Type | Description |
|---|---|---|
| device | | |
Device parameters. |
| options |
Options to be applied. |
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 ScrollView UI component in an application executed on the desktop.
jQuery
DevExpress.ui.dxScrollView.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the ScrollView properties
}
});Angular
import ScrollView, { Properties } from "devextreme/ui/scroll_view";
// ...
export class AppComponent {
constructor () {
ScrollView.defaultOptions<Properties>({
device: { deviceType: "desktop" },
options: {
// Here go the ScrollView properties
}
});
}
}Vue
<template>
<div>
<DxScrollView id="scrollView1" />
<DxScrollView id="scrollView2" />
</div>
</template>
<script>
import DxScrollView from "devextreme-vue/scroll-view";
import ScrollView from "devextreme/ui/scroll_view";
ScrollView.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the ScrollView properties
}
});
export default {
components: {
DxScrollView
}
}
</script>React
import dxScrollView from "devextreme/ui/scroll_view";
import ScrollView from "devextreme-react/scroll-view";
dxScrollView.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the ScrollView properties
}
});
export default function App() {
return (
<div>
<ScrollView id="scrollView1" />
<ScrollView id="scrollView2" />
</div>
)
}You can also set rules for multiple device types:
jQuery
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
DevExpress.ui.dxScrollView.defaultOptions({
device: deviceConfig,
options: {
// Here go the ScrollView properties
}
});
});Angular
import ScrollView, { Properties } from "devextreme/ui/scroll_view";
// ...
export class AppComponent {
constructor () {
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
ScrollView.defaultOptions<Properties>({
device: deviceConfig,
options: {
// Here go the ScrollView properties
}
});
});
}
}Vue
<template>
<div>
<DxScrollView />
</div>
</template>
<script>
import DxScrollView from "devextreme-vue/scroll-view";
import ScrollView from "devextreme/ui/scroll_view";
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
ScrollView.defaultOptions({
device: deviceConfig,
options: {
// Here go the ScrollView properties
}
});
});
export default {
components: {
DxScrollView
}
}
</script>React
import dxScrollView from "devextreme/ui/scroll_view";
import ScrollView from "devextreme-react/scroll-view";
const devicesConfig = [
{ deviceType: 'desktop' },
{ deviceType: 'tablet' },
{ deviceType: 'phone' },
];
devicesConfig.forEach(deviceConfig => {
dxScrollView.defaultOptions({
device: deviceConfig,
options: {
// Here go the ScrollView properties
}
});
});
export default function App() {
return (
<div>
<ScrollView />
</div>
)
}dispose()
jQuery
After calling this method, remove the DOM element associated with the UI component:
$("#myScrollView").dxScrollView("dispose");
$("#myScrollView").remove();Angular
Use conditional rendering instead of this method:
<dx-scroll-view ...
*ngIf="condition">
</dx-scroll-view>Vue
Use conditional rendering instead of this method:
<template>
<DxScrollView ...
v-if="condition">
</DxScrollView>
</template>
<script>
import DxScrollView from 'devextreme-vue/scroll-view';
export default {
components: {
DxScrollView
}
}
</script>React
Use conditional rendering instead of this method:
import React from 'react';
import ScrollView from 'devextreme-react/scroll-view';
function DxScrollView(props) {
if (!props.shouldRender) {
return null;
}
return (
<ScrollView ... >
</ScrollView>
);
}
class App extends React.Component {
render() {
return (
<DxScrollView shouldRender="condition" />
);
}
}
export default App;endUpdate()
Refreshes the UI component after a call of the beginUpdate() method.
The beginUpdate() and endUpdate() methods reduce the number of renders in cases where extra rendering can negatively affect performance.
See Also
getInstance(element)
getInstance is a static method that the UI component class supports. The following code demonstrates how to get the ScrollView instance found in an element with the myScrollView ID:
// Modular approach
import ScrollView from "devextreme/ui/scroll_view";
...
let element = document.getElementById("myScrollView");
let instance = ScrollView.getInstance(element) as ScrollView;
// Non-modular approach
let element = document.getElementById("myScrollView");
let instance = DevExpress.ui.dxScrollView.getInstance(element);See Also
on(eventName, eventHandler)
Use this method to subscribe to one of the events listed in the Events section.
See Also
on(events)
Use this method to subscribe to several events with one method call. Available events are listed in the Events section.
See Also
refresh()
Locks the UI component until the release(preventScrollBottom) method is called and executes the function passed to the onPullDown property and the handler assigned to the pullDown event.
release(preventScrollBottom)
Specifies whether to prevent the onReachBottom handler execution.
A Promise that is resolved after the UI component is released. It is a native Promise or a jQuery.Promise when you use jQuery.
Use this method to hide the load indicator and release the scroll view after the pullDown or reachBottom events have been raised.
See Also
update()
A Promise that is resolved after the update is completed. It is a native Promise or a jQuery.Promise when you use jQuery.
Use this method to fit the UI component's contents to the UI component's size if it changes.