JavaScript/jQuery Gantt Methods

The resource key.

taskKey:

The task key.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.assignResourceToTask("resource_key","task_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

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.

defaultOptions(rule)

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

Parameters:

rule:

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.

Name

Type

Description

device

Device

|

Array<Device>

|

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

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 Gantt UI component in an application executed on the desktop.


import React, {useEffect} from "react";
import dxGantt from "devextreme/ui/gantt";
import Gantt from "devextreme-react/gantt";
 
export default function App() {
    useEffect(() => { 
        dxGantt.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Gantt properties
            }
        })
    });
 
    return (
        <div>
            <Gantt id="gantt1" />
            <Gantt id="gantt2" />
        </div>
    )
}

deleteDependency(key)

Deletes a dependency.

Parameters:

key:

The dependency key.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.deleteDependency("dependency_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

deleteResource(key)

Deletes a resource.

Parameters:

key:

The resource key.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.deleteResource("resource_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

deleteTask(key)

Deletes a task.

Parameters:

key:

The task key.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.deleteTask("task_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

dispose()

Disposes of all the resources allocated to the Gantt instance.

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

JavaScript


$("#myGantt").dxGantt("dispose");
$("#myGantt").remove();

Use this method only if the UI component was created with jQuery or pure JavaScript. In Angular, Vue, and React, use conditional rendering:

App.js


import React from 'react';
 
import Gantt from 'devextreme-react/gantt';
 
function DxGantt(props) {
    if (!props.shouldRender) {
        return null;
    }
 
    return (
        <Gantt ... >    
        </Gantt>
    );
}
 
class App extends React.Component {
    render() {
        return (
            <DxGantt shouldRender="condition" />
        );
    }
}
export default App;

element()

Gets the root UI component element.

Return Value:

HTMLElement | jQuery

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

endUpdate()

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

Main article: beginUpdate()

focus()

Sets focus on the UI component.

getDependencyData(key)

Gets the dependency data.

Parameters:

key:

The dependency key.

Return Value:

The dependency data.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getDependencyData("dependency_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

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:

The UI component's instance.

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


// Modular approach
import Gantt from "devextreme/ui/gantt";
...
let element = document.getElementById("myGantt");
let instance = Gantt.getInstance(element) as Gantt;
 
// Non-modular approach
let element = document.getElementById("myGantt");
let instance = DevExpress.ui.dxGantt.getInstance(element);

getResourceAssignmentData(key)

Gets the resource assignment data.

Parameters:

key:

The resource assignment key.

Return Value:

The resource assignment data.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getResourceAssignmentData("res_assignment_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getResourceData(key)

Gets the resource data.

Parameters:

key:

The resource key.

Return Value:

The resource data.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getResourceData("resource_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getTaskData(key)

Gets the task data.

Parameters:

key:

The task key.

Return Value:

The task data.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getTaskData("task_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getTaskResources(key)

Gets resources assigned to a task.

Parameters:

key:

The task's key.

Return Value:

The resources.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getTaskResources("task_key");
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getVisibleDependencyKeys()

Gets the keys of the visible dependencies.

Return Value:

The keys.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getVisibleDependencyKeys();
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getVisibleResourceAssignmentKeys()

Gets the keys of the visible resource assignments.

Return Value:

The keys.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getVisibleResourceAssignmentKeys();
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getVisibleResourceKeys()

Gets the keys of the visible resources.

Return Value:

The keys.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getVisibleResourceKeys();
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

getVisibleTaskKeys()

Gets the keys of the visible tasks.

Return Value:

The keys.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.getVisibleTaskKeys();
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

insertDependency(data)

Inserts a new dependency.

Parameters:

data:

The dependency data.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.insertDependency({ predecessorId: 1, successorId: 3, type: 3 });
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

insertResource(data, taskKeys)

Inserts a new resource.

Parameters:

data:

The resource data.

taskKeys?:

An array of task keys.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            // Inserts a new resource 
            this.gantt.insertResource({ text: "New Resource" });
 
            // Inserts a new resource and assigns it to an individual task
            this.gantt.insertResource({ text: "New Resource" }, [6]);
 
            // Inserts a new resource and assigns it to multiple tasks
            this.gantt.insertResource({ text: "New Resource" }, [6,8]);
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

insertTask(data)

Inserts a new task.

Parameters:

data:

The task data.

The insertTask method does not update the following data fields in the data source:

Key value fields.
Fields that are not assigned to the Gantt's columns.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            // Inserts a new task with the specified subject at the end of the other tasks.
            this.gantt.insertTask({ title: "New Task" });
 
            // Inserts a child task with the specified subject as a child of the task with ID = 2
            this.gantt.insertTask({ title: "New Task" , parentId: 2});
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

instance()

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

Return Value:

This UI component's instance.

off(eventName)

Detaches all event handlers from a single event.

Parameters:

eventName:

The event's name.

Return Value:

The object for which this method is called.

off(eventName, eventHandler)

Detaches a particular event handler from a single event.

Parameters:

eventName:

The event's name.

eventHandler:

The event's handler.

Return Value:

The object for which this method is called.

on(eventName, eventHandler)

Subscribes to an event.

Parameters:

eventName:

The event's name.

eventHandler:

The event's handler.

Return Value:

The object for which this method is called.

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

on(events)

Subscribes to events.

Parameters:

events:

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

Return Value:

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.

option()

Gets all UI component properties.

Return Value:

The UI component's properties.

option(optionName)

Gets the value of a single property.

Parameters:

optionName:

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:

The property's name or full path.

optionValue: any

This property's new value.

option(options)

Updates the values of several properties.

Parameters:

options:

Options with their new values.

registerKeyHandler(key, handler)

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

Parameters:

key:

A key.

handler:

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.

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.

Parameters:

optionName:

A property's name.

unassignResourceFromTask(resourceKey, taskKey)

Removes a resource from the task.

Parameters:

resourceKey:

The resource key.

taskKey:

The task key.

App.js


import React from 'react';
 
import 'devextreme/dist/css/dx.light.css';
 
import Gantt from 'devextreme-react/gantt';
 
class App extends React.Component {
    constructor(props) {
        super(props);
 
        this.ganttRef = React.createRef();
 
        this.yourCustomMethod = () => {
            this.gantt.unassignResourceFromTask(3, 10);
            // ...
        }
    }
 
    get gantt() {
        return this.ganttRef.current.instance;
    }
 
    render() {
        return (
            <Gantt ...
                ref={this.ganttRef}>
            </Gantt>
        );
    }
}
export default App;

updateDimensions()

Updates the dimensions of the UI component contents.

updateTask(key, data)

Updates the task data.

Parameters:

key:

The task key.

data: