Angular Form Methods

This section describes members used to manipulate a widget.

beginUpdate()

Prevents the widget from refreshing until the endUpdate() method is called.

The beginUpdate() and endUpdate() methods prevent the widget from excessive updates when you are changing multiple widget settings at once. After the beginUpdate() method is called, the widget does not update its UI until the endUpdate() method is called.

See Also

defaultOptions(rule)

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

Parameters:
rule:

Object

The component's default device options.

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 options should be applied to the device.
options

Object

Options to be applied.

defaultOptions is a static method that the widget class supports. The following code demonstrates how to specify default options for all instances of the Form widget in an application executed on the desktop.

jQuery
JavaScript
DevExpress.ui.dxForm.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the Form options
    }
});
Angular
TypeScript
import Form from 'devextreme/ui/form';
// ...
export class AppComponent {
    constructor () {
        Form.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Form options
            }
        });
    }
}

dispose()

Disposes of all the resources allocated to the Form instance.

The following code disposes of an Form instance that corresponds to the element ID (or reference variable in Angular) and removes the element from the DOM:

jQuery
JavaScript
$("#myForm").dxForm("dispose");
$("#myForm").remove();
Angular
HTML
<dx-form #formVar id="myForm"></dx-form>
TypeScript
import { ..., ViewChild } from "@angular/core";
import { DxFormComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild("formVar") form: DxFormComponent;

    removeForm (e) {
        this.form.instance.dispose();
        document.getElementById("myForm").remove();
    }
}

element()

Gets the root widget element.

Return Value:

HTMLElement | jQuery

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

See Also

endUpdate()

Refreshes the widget after a call of the beginUpdate() method.

Main article: beginUpdate()

See Also

focus()

Sets focus on the widget.

See Also

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: any

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
        }
    });
});
See Also

getInstance(element)

Gets the instance of a widget found using its DOM node.

Parameters:
element:

DOM Node

|

jQuery

The widget's container.

Return Value:

Object

The widget's instance.

getInstance is a static method that the widget 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 widget's instance. Use it to access other methods of the widget.

Return Value:

Object

This widget's instance.

See Also

itemOption(id)

Gets a form item's configuration.

Parameters:
id:

String

An item's name or a path to it.
The path may include the group's 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 option.

Parameters:
id:

String

An item's name or a path to it.
The path may include the group's caption or the tab's title.

option:

String

The option's name.

value: any

The new option value.

The following code shows how to call this method for an item organized 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");
});
JavaScript
form.itemOption("Contacts.phone", "visible", false)
See Also

itemOption(id, options)

Updates the values of several item options.

Parameters:
id:

String

An item's name or a path to it.
The path may include the group's caption or the tab's title.

options:

Object

Options and their new values.

See Also

off(eventName)

Detaches all event handlers from a single event.

Parameters:
eventName:

String

The event's name.

Return Value:

Object

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:

Object

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:

Object

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:

Object

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()

Gets all widget options.

Return Value:

Object

The widget's options.

See Also

option(optionName)

Gets the value of a single option.

Parameters:
optionName:

String

The option's name or full path.

Return Value: any

This option's value.

See Also

option(optionName, optionValue)

Updates the value of a single option.

Parameters:
optionName:

String

The option's name or full path.

optionValue: any

This option's new value.

See Also

option(options)

Updates the values of several options.

Parameters:
options:

Object

Options with their new values.

See Also

registerKeyHandler(key, handler)

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

Parameters:
key:

String

The key.

handler:

Function

The handler.

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 widget. Call it if you made modifications that changed the widget's state to invalid.

See Also

resetValues()

Resets the editor's value to undefined.

See Also

updateData(data)

Updates formData fields and the corresponding editors.

Parameters:
data:

Object

Data fields with their new values.

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 widget 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 widget contents to the widget 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:

Object

The validation result.

The returned object contains the following fields:

  • isValid: Boolean
    Indicates whether all the rules checked for the group are satisfied.

  • brokenRules: Array
    Rules that failed to pass the check. Their structure is described in the Validation Rules section.

  • validators: Array
    Validator widgets included in the validated group.

See Also