React Common - utils

This section describes an API that can be used in different application parts such as widgets, data and the application framework.

animationPresets

A repository of animations.

import animationPresets from "devextreme/animation/presets"

To avoid defining animations each time you animate an element(s), register different animations in the DevExtreme.animationPresets repository and request them by associated names when required. This repository has a built-in set of animations. Here they are:

  • fade
  • stagger-fade
  • slide
  • stagger-slide
  • ios7-slide
  • overflow
  • ios7-toolbar
  • stagger-smooth-drop
  • stagger-drop
  • stagger-3d-drop
NOTE
Stagger-like animations are executed by the transitionExecutor only. They cannot be applied by calling the animate method for a particular element.

To populate the animationPresets repository with your animations, use the registerPreset(name, config) method. To get the required animation from the repository, use the getPreset(name) method.

config()

Gets the current global configuration.

import config from "devextreme/core/config"
Return Value:

GlobalConfig

config(config)

Configures your application before its launch.

import config from "devextreme/core/config"
Parameters:
config:

GlobalConfig

Global configuration options.

DevExpress.config({ rtlEnabled: true, forceIsoDateParsing: false, // ... }); // ===== or when using modules ===== import config from "devextreme/core/config";

config({
    rtlEnabled: true,
    forceIsoDateParsing: false,
    // ...
})
NOTE
This method should be called only once - at the application's launch. It is necessary to reload the page each time you need to apply new global configuration parameters.

devices

An object that serves as a namespace for the methods and events specifying information on the current device.

events

This namespace provides methods for controlling events without using jQuery.

fx

An object that serves as a namespace for the methods that are used to animate UI elements.

import fx from "devextreme/animation/fx"

hideTopOverlay()

Hides the last displayed overlay widget.

import hideTopOverlay from "devextreme/mobile/hide_top_overlay"
Return Value:

Boolean

true if hiding was successful; false if not or if no displayed overlay widget was found.

localization

An object that serves as a namespace for the methods that are used to localize an application.

processHardwareBackButton()

Processes the hardware back button click.

import processHardwareBackButton from "devextreme/mobile/process_hardware_back_button"

When building a mobile application, you should initiate processing of the hardware back button click. The following code demonstrates how to do this by calling the processHardwareBackButton() method within the event listener of the PhoneGap backbutton event.

JavaScript
$(function() {
    document.addEventListener("deviceready", onDeviceReady, false);
    function onDeviceReady() {
        //...
        document.addEventListener("backbutton", onBackButton, false);
    }
    function onBackButton() {
        DevExpress.processHardwareBackButton();
    }    
    //...    
}

To handle the back button click, subscribe to the HtmlApplication.navigatingBack() event and use the isHardwareButton event handler parameter within the handling function.

TransitionExecutor

The manager that performs several specified animations at a time.

import TransitionExecutor from "devextreme/animation/transition_executor"

While there are scenarios when animating certain elements is required, there can be more complex scenarios when you need to perform a transition - several animations of different elements performed simultaneously. For instance, when you navigate from a view to another view in a mobile application, the content of the new view replaces the content of the old view. Moreover, the header can be animated differently from the rest of the content on both views. Thus, four different animations must be performed simultaneously. To simplify the implementation of such scenarios, the TransitionExecutor is implemented.

To register the set of animations to be performed simultaneously, use the enter(elements, animation) and leave(elements, animation) methods of the TransitionExecutor object. Use the enter(elements, animation) method to specify the elements that should appear ("enter") on the page with a specified animation. The leave(elements, animation) method should be called if there are elements that must disappear ("leave") from the page.

The TransitionExecutor object is also useful when a need arises to perform a staggered animation of elements when elements are animated with a slight delay after animation of each successive element starts resulting in a curtain-like effect. In this instance, each element should be registered with by the enter(elements, animation)/leave(elements, animation) method with the animation configuration where the staggerDelay option is specified.

To start a transition, call the start() method of the TransitionExecutor object. To clear the registered set of animations in the TransitionExecutor object, call the reset() method.

NOTE
The Transition Executor is used automatically in [DevExtreme SPA applications) to animate different parts of views. You need to provide a particular set of animations for the application only.

ui

An object that serves as a namespace for DevExtreme UI widgets as well as for methods implementing UI logic in DevExtreme sites/applications.

utils

An object that serves as a namespace for utility methods that can be helpful when working with the DevExtreme framework and UI widgets.

validationEngine

An object that serves as a namespace for the methods required to perform validation.

import validationEngine from "devextreme-react/validation-engine"

viz

An object that serves as a namespace for DevExtreme Data Visualization Widgets.

Errors and Warnings

This section lists core errors and warnings that may occur in DevExtreme applications.