Angular Diagram Methods

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 Diagram UI component in an application executed on the desktop.

jQuery

JavaScript

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

Angular

TypeScript

import Diagram from "devextreme/ui/diagram";
// ...
export class AppComponent {
    constructor () {
        Diagram.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Diagram properties
            }
        });
    }
}

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 properties
    }
});

export default {
    components: {
        DxDiagram
    }
}
</script>

React

import React, {useEffect} from "react";
import dxDiagram from "devextreme/ui/diagram";
import Diagram from "devextreme-react/diagram";

export default function App() {
    useEffect(() => { 
        dxDiagram.defaultOptions({
            device: { deviceType: "desktop" },
            options: {
                // Here go the Diagram properties
            }
        })
    });

    return (
        <div>
            <Diagram id="diagram1" />
            <Diagram id="diagram2" />
        </div>
    )
}

dispose()

Disposes of all the resources allocated to the Diagram instance.

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

JavaScript

$("#myDiagram").dxDiagram("dispose");
$("#myDiagram").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-diagram ...
    *ngIf="condition">
</dx-diagram>

Vue

App.vue

<template>
    <DxDiagram ...
        v-if="condition">
    </DxDiagram>
</template>

<script>
import DxDiagram from 'devextreme-vue/diagram';

export default {
    components: {
        DxDiagram
    }
}
</script>

React

App.js

import React from 'react';

import Diagram from 'devextreme-react/diagram';

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

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

class App extends React.Component {
    render() {
        return (
            <DxDiagram 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()

export()

Exports the diagram data to a JSON object.

Return Value:

The diagram data in JSON format.

The export method allows you to save information about a diagram's layout, appearance, and the diagram's shape positions.

The component saves the diagram's data in its own text format. The resulting JSON object contains measurements in twips, regardless of the units or viewUnits property values. Do not modify this JSON object because modified data can load incorrectly.

Use the import method to load this data on demand.

exportTo(format, callback)

Exports the diagram to an image format.

Parameters:

format: 'svg' | 'png' | 'jpg'

The image format.

callback:

A function to be executed after a diagram image is prepared and allows you to save the image.

The export to an image in Internet Explorer (using the exportTo method or the UI) requires the canvg library.

focus()

Sets focus on the UI component.

getEdgeDataSource()

Returns the DataSource instance.

Return Value:

DataSource

The DataSource instance.

NOTE

This method returns the DataSource instance even if the dataSource property of the layer was given a simple array.

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 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);

getItemById(id)

Returns a shape or connector object specified by its internal identifier.

Parameters:

id:

The item identifier.

Return Value:

dxDiagramItem

A dxDiagramItem object descendant (dxDiagramShape or dxDiagramConnector).

When a user pastes or clones several items in a diagram, the control adds the items to the model one by one. For each added item, the requestEditOperation event fires. In the event handler, you can access the processed item. However, if you call the getItemById method to access an attached connector (see the attachedConnectorIds property) or a container's child item (see the containerChildItemIds property), you can get the undefinedresult if the item is not added to the model yet.

getItemByKey(key)

Returns a shape or connector object specified by its key.

Parameters:

key:

The item key.

Return Value:

dxDiagramItem

A dxDiagramItem object descendant (dxDiagramShape or dxDiagramConnector).

An item key specifies the item's identifier in a data source. If a diagram is not bound to a data source, the key value is empty. In this instance, use the GetItemById(id) method to get an item by its internal identifier. An item always has an identifier.

getItems()

Returns an array of diagram items.

Return Value:

Array<dxDiagramItem>

An array of items (shapes and connectors).

Call the getItems method to get the full collection of diagram items.

getNodeDataSource()

Gets the DataSource instance.

Return Value:

DataSource

The DataSource instance.

NOTE

This method returns the DataSource instance even if the dataSource property of the layer was given a simple array.

getSelectedItems()

Returns an array of selected diagram items.

Return Value:

Array<dxDiagramItem>

An array of items (shapes and connectors).

import(data, updateExistingItemsOnly)

Imports the diagram data.

Parameters:

data:

The diagram data in JSON format.

updateExistingItemsOnly?:

Boolean

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

The export method allows you to save information about a diagram's layout, appearance, and the diagram's shape positions.

Use the import method to load this data on demand.

NOTE

The Diagram stores an opened diagram's data in its own text format. Do not modify the data the export method returns because a modified document can be loaded incorrectly.

View Demo

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.

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: