CascadeSelect
CascadeSelect displays a nested structure of options.
Import #
import { CascadeSelectModule } from 'primeng/cascadeselect';Basic #
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.
Template #
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.
Loading State #
Loading state can be used loading property.
Float Label #
A floating label appears on top of the input field when focused. Visit FloatLabel documentation for more information.
Ifta Label #
IftaLabel is used to create infield top aligned labels. Visit IftaLabel documentation for more information.
Clear Icon #
When showClear is enabled, a clear icon is displayed to clear the value.
Sizes #
CascadeSelect provides small and large sizes as alternatives to the base.
Fluid #
The fluid prop makes the component take up the full width of its container when set to true.
Filled #
Specify the variant property as filled to display the component with a higher visual emphasis than the default outlined style.
Disabled #
When disabled is present, the element cannot be edited and focused.
Invalid #
The invalid state is applied using the invalid property to indicate failed validation, which can be integrated with Angular Forms.
Forms #
Template Driven #
Reactive Forms #
CascadeSelect can also be used with reactive forms. In this case, the formControlName property is used to bind the component to a form control.
Accessibility #
Screen Reader
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"/>Closed State Keyboard Support
| 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. |
Popup Keyboard Support
| 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. |
