CascadeSelect displays a nested structure of options.
import { CascadeSelectModule } from 'primeng/cascadeselect';
CascadeSelect requires a value to bind and a collection of arbitrary objects with a nested hierarchy. optionGroupLabel is used for the text of a category and optionGroupChildren is to define the children of the category. Note that order of the optionGroupChildren matters and it should correspond to the data hierarchy.
<p-cascadeselect [(ngModel)]="selectedCity" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" [style]="{ minWidth: '14rem' }" placeholder="Select a City" />
CascadeSelect can also be used with reactive forms. In this case, the formControlName property is used to bind the component to a form control.
<form [formGroup]="formGroup">
<p-cascadeselect formControlName="selectedCity" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" [style]="{ minWidth: '14rem' }" placeholder="Select a City" />
</form>
Label of an option is used as the display text of an item by default, for custom content support define an option template that gets the option instance as a parameter. In addition value, dropdownicon, loadingicon, and optiongroupicon slots are provided for further customization.
<p-cascadeselect [(ngModel)]="selectedCity" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" [style]="{ minWidth: '14rem' }" placeholder="Select a City">
<ng-template #option let-option>
<div class="flex items-center">
<img *ngIf="option.states" src="https://primefaces.org/cdn/primeng/images/demo/flag/flag_placeholder.png" [class]="'mr-2 flag flag-' + option.code.toLowerCase()" style="width: 18px" />
<i class="pi pi-compass mr-2" *ngIf="option.cities"></i>
<i class="pi pi-map-marker mr-2" *ngIf="option.cname"></i>
<span>{{ option.cname || option.name }}</span>
</div>
</ng-template>
<ng-template #triggericon>
<i class="pi pi-map"></i>
</ng-template>
<ng-template #header>
<div class="font-medium px-3 py-2">Available Countries</div>
</ng-template>
<ng-template #footer>
<div class="px-3 py-1">
<p-button label="Add New" fluid severity="secondary" text size="small" icon="pi pi-plus" />
</div>
</ng-template>
</p-cascadeselect>
Loading state can be used loading property.
<p-cascadeselect [loading]="true" [style]="{ minWidth: '14rem' }" placeholder="Loading..." />
A floating label appears on top of the input field when focused. Visit FloatLabel documentation for more information.
<p-floatlabel class="w-full md:w-56">
<p-cascadeselect [(ngModel)]="value1" inputId="over_label" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-full" />
<label for="over_label">Over Label</label>
</p-floatlabel>
<p-floatlabel class="w-full md:w-56" variant="in">
<p-cascadeselect [(ngModel)]="value2" inputId="in_label" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-full" />
<label for="in_label">In Label</label>
</p-floatlabel>
<p-floatlabel class="w-full md:w-56" variant="on">
<p-cascadeselect [(ngModel)]="value3" inputId="on_label" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-full" />
<label for="on_label">On Label</label>
</p-floatlabel>
IftaLabel is used to create infield top aligned labels. Visit IftaLabel documentation for more information.
<p-iftalabel class="w-full md:w-56">
<p-cascadeselect [(ngModel)]="selectedCity" inputId="cs_city" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-full" />
<label for="cs_city">City</label>
</p-iftalabel>
CascadeSelect provides small and large sizes as alternatives to the base.
<p-cascadeselect [(ngModel)]="value1" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-56" size="small" placeholder="Small" />
<p-cascadeselect [(ngModel)]="value2" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-56" placeholder="Normal" />
<p-cascadeselect [(ngModel)]="value3" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" styleClass="w-56" size="large" placeholder="Large" />
Specify the variant property as filled to display the component with a higher visual emphasis than the default outlined style.
<p-cascadeselect [(ngModel)]="selectedCity" variant="filled" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" [style]="{ minWidth: '14rem' }" placeholder="Select a City" />
Invalid state style is added using the ng-invalid and ng-dirty class to indicate a failed validation.
<p-cascadeselect class="ng-invalid ng-dirty" [(ngModel)]="selectedCity" [options]="countries" optionLabel="cname" optionGroupLabel="name" [optionGroupChildren]="['states', 'cities']" [style]="{ minWidth: '14rem' }" placeholder="Select a City" />
When disabled is present, the element cannot be edited and focused.
<p-cascadeselect [disabled]="true" placeholder="Disabled" [style]="{ minWidth: '14rem' }" />
Value to describe the component can either be provided with ariaLabelledBy or ariaLabel props. The cascadeselect element has a combobox role in addition to aria-haspopup and aria-expanded attributes. The relation between the combobox and the popup is created with aria-controls that refers to the id of the popup.
The popup list has an id that refers to the aria-controls attribute of the combobox element and uses tree as the role. Each list item has a treeitem role along with aria-label, aria-selected and aria-expanded attributes. The container element of a treenode has the group role. The aria-setsize, aria-posinset and aria-level attributes are calculated implicitly and added to each treeitem.
<span id="dd1">Options</span>
<p-cascadeselect ariaLabelledBy="dd1"/>
<p-cascadeselect ariaLabel="Options"/>
| Key | Function |
|---|---|
| tab | Moves focus to the cascadeselect element. |
| space | Opens the popup and moves visual focus to the selected option, if there is none then first option receives the focus. |
| down arrow | Opens the popup and moves visual focus to the selected option, if there is none then first option receives the focus. |
| Key | Function |
|---|---|
| tab | Hides the popup and moves focus to the next tabbable element. |
| shift + tab | Hides the popup and moves focus to the previous tabbable element. |
| enter | Selects the focused option and closes the popup. |
| space | Selects the focused option and closes the popup. |
| escape | Closes the popup, moves focus to the cascadeselect element. |
| down arrow | Moves focus to the next option. |
| up arrow | Moves focus to the previous option. |
| right arrow | If option is closed, opens the option otherwise moves focus to the first child option. |
| left arrow | If option is open, closes the option otherwise moves focus to the parent option. |