JavaScript/jQuery Diagram Methods
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.
See Also
defaultOptions(rule)
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
DevExpress.ui.dxDiagram.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the Diagram properties
}
});Angular
import Diagram, { Properties } from "devextreme/ui/diagram";
// ...
export class AppComponent {
constructor () {
Diagram.defaultOptions<Properties>({
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 dxDiagram from "devextreme/ui/diagram";
import Diagram from "devextreme-react/diagram";
dxDiagram.defaultOptions({
device: { deviceType: "desktop" },
options: {
// Here go the Diagram properties
}
});
export default function App() {
return (
<div>
<Diagram id="diagram1" />
<Diagram id="diagram2" />
</div>
)
}dispose()
jQuery
After calling this method, remove the DOM element associated with the UI component:
$("#myDiagram").dxDiagram("dispose");
$("#myDiagram").remove();Angular
Use conditional rendering instead of this method:
<dx-diagram ...
*ngIf="condition">
</dx-diagram>Vue
Use conditional rendering instead of this method:
<template>
<DxDiagram ...
v-if="condition">
</DxDiagram>
</template>
<script>
import DxDiagram from 'devextreme-vue/diagram';
export default {
components: {
DxDiagram
}
}
</script>React
Use conditional rendering instead of this method:
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;endUpdate()
Refreshes the UI component after a call of the beginUpdate() method.
Main article: beginUpdate()
See Also
export()
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.
getEdgeDataSource()
Returns the DataSource instance.
See Also
getInstance(element)
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);See Also
getItemById(id)
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)
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()
The code sample below demonstrates how to get the full collection of diagram items and filter the items that are directly connected to the clicked item.
jQuery
$(() => {
$('#diagram').dxDiagram({
nodes: {
dataSource: new DevExpress.data.ArrayStore({
key: 'ID',
data: employees,
}),
keyExpr: 'ID',
textExpr: 'Full_Name',
parentKeyExpr: 'Head_ID',
},
onItemClick(e) {
var itemKey = e.item.key;
var connectors = e.component.getItems().filter(function (item) {
return item.itemType === "connector" && (item.fromKey === itemKey || item.toKey === itemKey);
});
var relativeShapes = [];
connectors.forEach(element => {
if (element.fromKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.toKey)); // all child shapes
if (element.toKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.fromKey)); // all parent shapes
});
},
}).dxDiagram('instance');
});Angular
<dx-diagram #diagram id="diagram" (onItemClick)="itemClickHandler($event)">
<dxo-nodes [dataSource]="dataSource" keyExpr="ID" textExpr="Full_Name" parentKeyExpr="Head_ID" />
</dx-diagram>
// ...
itemClickHandler(e) {
var itemKey = e.item.key;
var connectors = e.component.getItems().filter(function (item) {
return item.itemType === "connector" && (item.fromKey === itemKey || item.toKey === itemKey);
});
var relativeShapes = [];
connectors.forEach(element => {
if (element.fromKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.toKey)); // all subsequent shapes
if (element.toKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.fromKey)); // all previous shapes
});
}
// ...Vue
<template>
<DxDiagram
id="diagram"
ref="diagram"
@item-click="onItemClick"
>
<DxNodes
:data-source="dataSource"
:key-expr="'ID'"
:text-expr="'Full_Name'"
:parent-key-expr="'Head_ID'"
>
<DxAutoLayout
:type="'tree'"
/>
</DxNodes>
</DxDiagram>
</template>
<script>
// ...
onItemClick(e) {
var itemKey = e.item.key;
var connectors = e.component.getItems().filter(function (item) {
return item.itemType === "connector" && (item.fromKey === itemKey || item.toKey === itemKey);
});
var relativeShapes = [];
connectors.forEach(element => {
if (element.fromKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.toKey)); // all subsequent shapes
if (element.toKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.fromKey)); // all previous shapes
});
console.log(relativeShapes);
},
// ...
</script>React
tab: App.js
class App extends React.Component { constructor(props) { // ... onItemClick(e) { var itemKey = e.item.key; var connectors = e.component.getItems().filter(function (item) { return item.itemType === "connector" && (item.fromKey === itemKey || item.toKey === itemKey); }); var relativeShapes = []; connectors.forEach(element => { if (element.fromKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.toKey)); // all subsequent shapes if (element.toKey === itemKey) relativeShapes.push(e.component.getItemByKey(element.fromKey)); // all previous shapes }); }, // ... }
render() {
return (
getNodeDataSource()
Gets the DataSource instance.
See Also
import(data, updateExistingItemsOnly)
The export method allows you to save information about a diagram's layout, appearance, and shape positions. Use the import method to load this data on demand.
The diagram import updates the bound data source's field values. If the values are not changed, the corresponding events (for instance, onInserted and onUpdated) do not fire.
on(eventName, eventHandler)
Use this method to subscribe to one of the events listed in the Events section.
See Also
on(events)
Use this method to subscribe to several events with one method call. Available events are listed in the Events section.