JavaScript/jQuery Diagram Methods

This section describes members used to manipulate the widget.

See Also

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

createDataSource(parameters)

Populates the toolbox with items from a data source.

Parameters:
parameters: DiagramDataSourceParameters

Data source parameters.

View Demo

jQuery
JavaScript
$(function() {
    var diagram = $("#diagram").dxDiagram()
        .dxDiagram("instance");
    diagram.createDataSource({
        key: "0",
        title: "Employees",
        nodes: {
            dataSource: employees,
            keyExpr: "ID",
            textExpr: function(item) {
                return item && item.Full_Name.replace(" ", "\n");
            },
            parentKeyExpr: "Head_ID"
        },
        layout: "tree"
    });
});

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 Diagram widget in an application executed on the desktop.

jQuery
JavaScript
DevExpress.ui.dxDiagram.defaultOptions({ 
    device: { deviceType: "desktop" },
    options: {
        // Here go the Diagram options
    }
});
Angular
TypeScript
import Diagram from "devextreme/ui/diagram";
// ...
export class AppComponent {
    constructor () {
        Diagram.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Diagram options
            }
        });
    }
}
Vue
<template>
    <div>
        <DxDiagram id="diagram1" />
        <DxDiagram id="diagram2" />
    </div>
</template>
<script>
import DxDiagram from "devextreme-vue/diagram";
import Diagram from "devextreme/ui/diagram";

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

export default {
    components: {
        DxDiagram
    }
}
</script>
React
import React from "react";
import dxDiagram from "devextreme/ui/diagram";
import Diagram from "devextreme-react/diagram";

class App extends React.Component {
    render () {
        dxDiagram.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Diagram options
            }
        })
        return (
            <div>
                <Diagram id="diagram1" />
                <Diagram id="diagram2" />
            </div>
        )
    }
}

export default App;

deleteDataSource(key)

Removes data source items from the toolbox.

Parameters:
key:

String

The data source's key.

dispose()

Disposes of all the resources allocated to the Diagram instance.

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

jQuery
JavaScript
$("#myDiagram").dxDiagram("dispose");
$("#myDiagram").remove();
Angular
HTML
<dx-diagram #diagramVar id="myDiagram"></dx-diagram>
TypeScript
import { ..., ViewChild } from "@angular/core";
import { DxDiagramComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild("diagramVar", { static: false }) diagram: DxDiagramComponent;
    // Prior to Angular 8
    // @ViewChild("diagramVar") diagram: DxDiagramComponent;

    removeDiagram (e) {
        this.diagram.instance.dispose();
        document.getElementById("myDiagram").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

getData()

Gets the diagram data.

Return Value:

String

The diagram data in JSON format.

The getData method allows you to save information about a diagram's layout, appearance, and the diagram's shape positions. You can call the setData method to save this data and load it on demand.

jQuery
JavaScript
$("#diagram").dxDiagram({
    onDataChanged: function(e) { 
        if(e.component.isReady()) {
            var data = e.component.getData();
            window.localStorage.setItem("foo", data); // store layout data in storage
        }
    },
    // ...
    onContentReady: function(e) { 
        var foo = window.localStorage.getItem("foo"); // load layout data and apply it to the generated shapes
        if(foo)
            e.component.setData(foo, true);
    }
});

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 Diagram instance found in an element with the myDiagram ID:

// Modular approach
import Diagram from "devextreme/ui/diagram";
...
let element = document.getElementById("myDiagram");
let instance = Diagram.getInstance(element) as Diagram;

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

instance()

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

Return Value:

Diagram

This widget's instance.

See Also

off(eventName)

Detaches all event handlers from a single event.

Parameters:
eventName:

String

The event's name.

Return Value:

Diagram

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:

Diagram

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:

Diagram

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:

Diagram

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

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 widget without reloading data. Call it to update the widget's markup.

See Also

setData(data, updateExistingItemsOnly)

Sets the diagram data.

Parameters:
data:

String

Contains information about a diagram's layout, appearance, and shape positions.

updateExistingItemsOnly:

Boolean

true to apply diagram data without rewriting diagram items; false to apply diagram data and replace diagram items with the items from the data parameter.

The getData method allows you to save information about a diagram's layout, appearance, and the diagram's shape positions. Use the setData method to load this data on demand.

jQuery
JavaScript
$("#diagram").dxDiagram({
    onDataChanged: function(e) { 
        if(e.component.isReady()) {
            var data = e.component.getData();
            window.localStorage.setItem("foo", data); // store layout data in storage
        }
    },
    // ...
    onContentReady: function(e) { 
        var foo = window.localStorage.getItem("foo"); // load layout data and apply it to the generated shapes
        if(foo)
            e.component.setData(foo, true);
    }
});