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Persisting the Disabled State
The TreeView enables you to define and persist the disabled state of its nodes when the component is re-rendered.
Basics
The TreeView determines the disabled state of its nodes by exposing the isDisabled function.
import { Component } from '@angular/core';
import { Observable, of } from 'rxjs';
@Component({
selector: 'my-app',
template: `
<kendo-treeview
[isDisabled]="isDisabled" <-- this manages the nodes disabled state
kendoTreeViewExpandable <-- this manages the expand collapse state
[nodes]="data" <-- nodes are in the data field of the host component
textField="text" <-- node's text field should be displayed
[children]="fetchChildren" <-- fetchChildren function will provide the child nodes
[hasChildren]="hasChildren" <-- use fetchChildren function to check if node has children
>
</kendo-treeview>
`
})
export class AppComponent {
//A function that disables every item with a text field which equals to 'Decor'.
public isDisabled = (dataItem: any) => {
return dataItem.text === 'Decor';
}
public data: any[] = [{
text: "Furniture", items: [
{ text: "Tables & Chairs" },
{ text: "Sofas" },
{ text: "Occasional Furniture" }
]
}, {
text: "Decor", items: [
{ text: "Bed Linen" },
{ text: "Curtains & Blinds" },
{ text: "Carpets" }
]
}
];
public fetchChildren(node: any): Observable<any[]> {
//Return the node collection of the parent node as children.
return of(node.items);
}
public hasChildren(node: any): boolean {
//Check if the parent node has children.
return node.items && node.items.length > 0;
}
}Built-in Directives
To persist the disabled state of the TreeView, either:
Using the Built-In Directive
By default, the built-in DisableDirective persists the disabled items based on their hierarchical index.
Example
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Change Theme:
Setting an Item Field
You can also persist the disabled state of the TreeView by item field—for example, the text field.
Example
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Change Theme:
Disable Parent Nodes
By default, the TreeView component disables all child nodes of a disabled node. The component can be configured to disable parent nodes only without disabling its children by setting the disableParentNodesOnly field to true.
Example
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Change Theme:
