Methods

This section describes members used to manipulate a UI component.

See Also

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

defaultOptions(rule)

Specifies the device-dependent default configuration properties for this component.

Parameters:
rule:

Object

The component's default device properties.

Object structure:
Name Type Description
device

Device

|

Array<Device>

|

Function

Device parameters.
When specifying a function, get information about the current device from the argument. Return true if the properties should be applied to the device.

options

Object

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 Form UI component in an application executed on the desktop.

jQuery
JavaScript
DevExpress.ui.dxForm.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the Form properties
    }
});
Angular
TypeScript
import Form from "devextreme/ui/form";
// ...
export class AppComponent {
    constructor () {
        Form.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Form properties
            }
        });
    }
}
Vue
<template>
    <div>
        <DxForm id="form1" />
        <DxForm id="form2" />
    </div>
</template>
<script>
import DxForm from "devextreme-vue/form";
import Form from "devextreme/ui/form";

Form.defaultOptions({
    device: { deviceType: "desktop" },
    options: {
        // Here go the Form properties
    }
});

export default {
    components: {
        DxForm
    }
}
</script>
React
import React from "react";
import dxForm from "devextreme/ui/form";
import Form from "devextreme-react/form";

class App extends React.Component {
    render () {
        dxForm.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Form properties
            }
        })
        return (
            <div>
                <Form id="form1" />
                <Form id="form2" />
            </div>
        )
    }
}

export default App;

dispose()

Disposes of all the resources allocated to the Form instance.

After calling this method, remove the DOM element associated with the UI component:

JavaScript
$("#myForm").dxForm("dispose");
$("#myForm").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
app.component.html
<dx-form ...
    *ngIf="condition">
</dx-form>
Vue
App.vue
<template>
    <DxForm ...
        v-if="condition">
    </DxForm>
</template>

<script>
import DxForm from 'devextreme-vue/form';

export default {
    components: {
        DxForm
    }
}
</script>
React
App.js
import React from 'react';

import Form from 'devextreme-react/form';

function DxForm(props) {
    if (!props.shouldRender) {
        return null;
    }

    return (
        <Form ... >    
        </Form>
    );
}

class App extends React.Component {
    render() {
        return (
            <DxForm shouldRender="condition" />
        );
    }
}
export default App;
See Also

element()

Gets the root UI component element.

Return Value:

HTMLElement | jQuery

An HTML element or a jQuery element when you use jQuery.

See Also

endUpdate()

Refreshes the UI component after a call of the beginUpdate() method.

Main article: beginUpdate()

See Also

focus()

Sets focus on the UI component.

See Also

getButton(name)

Gets a button's instance.

Parameters:
name:

String

A button item's name.

Return Value:

Button

| undefined

The button's instance.

getEditor(dataField)

Gets an editor instance. Takes effect only if the form item is visible.

Parameters:
dataField:

String

The item's name or dataField.

Return Value: Editor | undefined

The editor instance.

The following code shows how to get an editor of an item in a group:

JavaScript
var form = $(function () {
    $("#formContainer").dxForm({
        formData: {
            firstName: "John",
            lastName: "Heart",
            phone: "+1(213) 555-9392",
            email: "jheart@dx-email.com"
        },
        items: ["firstName", "lastName", {
            itemType: "group",
            caption: "Contacts",
            items: ["phone", "email"]
        }]
    }).dxForm("instance");
    $("#buttonContainer").dxButton({
        text: "Customize Phone Editor",
        onClick: function (e) {
            var editor = form.getEditor("phone");
            // Customizations go here
        }
    });
});
NOTE
This method works only for predefined editors, and is unavailable when using a custom template.
See Also

getInstance(element)

Gets the instance of a UI component found using its DOM node.

Parameters:
element:

Element

|

jQuery

The UI component's container.

Return Value:

Object

The UI component's instance.

getInstance is a static method that the UI component class supports. The following code demonstrates how to get the Form instance found in an element with the myForm ID:

// Modular approach
import Form from "devextreme/ui/form";
...
let element = document.getElementById("myForm");
let instance = Form.getInstance(element) as Form;

// Non-modular approach
let element = document.getElementById("myForm");
let instance = DevExpress.ui.dxForm.getInstance(element);
See Also

instance()

Gets the UI component's instance. Use it to access other methods of the UI component.

Return Value:

Form

This UI component's instance.

See Also

itemOption(id)

Gets a form item's configuration.

Parameters:
id:

String

An item's name or path without spaces if the item is in a group or a tab.
The path may include the group's name or caption or the tab's title.

Return Value: any

The form item's configuration.

See Also

itemOption(id, option, value)

Updates the value of a single item property.

Parameters:
id:

String

An item's name or path without spaces if the item is in a group or a tab.
The path may include the group's name or caption or the tab's title.

option:

String

The property's name.

value: any

The new property value.

The following code shows how to call this method for an item organized in a group:

JavaScript
$(function () {
    const form = $("#formContainer").dxForm({
        formData: {
            firstName: "John",
            lastName: "Heart",
            phone: "+1(213) 555-9392",
            email: "jheart@dx-email.com"
        },
        items: ["firstName", "lastName", {
            itemType: "group",
            caption: "Contacts",
            name: "groupName",
            items: ["phone", "email"]
        }]
    }).dxForm("instance");
});
JavaScript
form.itemOption("groupName.phone", "visible", false);
// ==== or ====
form.itemOption("Contacts.phone", "visible", false);

When you modify an item, the Form also refreshes all other items in its group. If an item is not in a group, the whole Form is refreshed. To update only your chosen items, wrap them into a separate group.

See Also

itemOption(id, options)

Updates the values of several item properties.

Parameters:
id:

String

An item's name or path without spaces if the item is in a group or a tab.
The path may include the group's name or caption or the tab's title.

options:

Object

Options and their new values.

When you modify an item, the Form also refreshes all other items in its group. If an item is not in a group, the whole Form is refreshed. To update only your chosen items, wrap them into a separate group.

See Also

off(eventName)

Detaches all event handlers from a single event.

Parameters:
eventName:

String

The event's name.

Return Value:

Form

The object for which this method is called.

See Also

off(eventName, eventHandler)

Detaches a particular event handler from a single event.

Parameters:
eventName:

String

The event's name.

eventHandler:

Function

The event's handler.

Return Value:

Form

The object for which this method is called.

See Also

on(eventName, eventHandler)

Subscribes to an event.

Parameters:
eventName:

String

The event's name.

eventHandler:

Function

The event's handler.

Return Value:

Form

The object for which this method is called.

Use this method to subscribe to one of the events listed in the Events section.

See Also

on(events)

Subscribes to events.

Parameters:
events:

Object

Events with their handlers: { "eventName1": handler1, "eventName2": handler2, ...}

Return Value:

Form

The object for which this method is called.

Use this method to subscribe to several events with one method call. Available events are listed in the Events section.

See Also

option()

Return Value:

Object

The UI component's properties.

option(optionName)

Gets the value of a single property.

Parameters:
optionName:

String

The property's name or full path.

Return Value: any

This property's value.

option(optionName, optionValue)

Updates the value of a single property.

Parameters:
optionName:

String

The property's name or full path.

optionValue: any

This property's new value.

option(options)

Updates the values of several properties.

Parameters:
options:

Object

Options with their new values.

registerKeyHandler(key, handler)

Registers a handler to be executed when a user presses a specific key.

Parameters:
key:

String

A key.

handler:

Function

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.

See Also

resetOption(optionName)

Resets an property to its default value.

Parameters:
optionName:

String

An property's name.

See Also

resetValues()

Resets the editor's value to undefined.

See Also

updateData(data)

Merges the passed data object with formData. Matching properties in formData are overwritten and new properties added.

Parameters:
data:

Object

Data fields with their new values.

NOTE

This method does not replace the formData object. To replace it, use the option(optionName, optionValue) method as shown below:

JavaScript
formInstance.option("formData", newFormData);
See Also

updateData(dataField, value)

Updates a formData field and the corresponding editor.

Parameters:
dataField:

String

A path to the formData field.

value:

Object

The new field value.

See Also

updateDimensions()

Updates the dimensions of the UI component contents.

Return Value:

Promise<void> (jQuery or native)

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 contents to the UI component size after it (size) has been changed.

See Also

validate()

Validates the values of all editors on the form against the list of the validation rules specified for each form item.

Return Value:

dxValidationGroupResult

The validation result.

See Also