TriStateCheckbox is used to select either "true", "false" or "null" as the value.
import { TriStateCheckbox } from 'primereact/tristatecheckbox';
TriStateCheckbox is used as a controlled input with checked and onChange properties.
<TriStateCheckbox value={value} onChange={(e) => setValue(e.value)} />
With disabled it specifies that the element value cannot be altered.
<TriStateCheckbox disabled value={value} onChange={(e) => setValue(e.value)} />
<TriStateCheckbox className="p-invalid" />
<label>Invalid</label>
Formik is a popular library for handling forms in React.
<Toast ref={toast} />
<TriStateCheckbox
id="item"
name="item"
value={formik.values.item}
onChange={(e) => {
formik.setFieldValue('item', e.value);
}}
className={classNames({ 'p-invalid': formik.errors.item })}
/>
<div className="my-2">* I've read and accept the terms & conditions.</div>
{getFormErrorMessage('item')}
<Button type="submit" label="Submit" icon="pi pi-check" />
React Hook Form is another popular React library to handle forms.
<Toast ref={toast} />
<Controller
name="value"
control={control}
rules={{ required: 'Value is required.' }}
render={({ field, fieldState }) => (
<>
<TriStateCheckbox id={field.name} value={field.value} ref={field.ref} onChange={field.onChange} className={classNames({ 'p-invalid': fieldState.error })} />
<label>* I've read and accept the terms & conditions.</label>
{getFormErrorMessage(field.name)}
</>
)}
/>
<Button label="Submit" type="submit" icon="pi pi-check" />
Following is the list of structural style classes, for theming classes visit theming page.
Name | Element |
---|---|
p-chkbox | Container element |
p-tristatechkbox | Container element |
p-chkbox-box | Container of icon. |
p-chkbox-icon | Icon element. |
TriStateCheckbox component uses an element with checkbox role. Value to describe the component can either be provided with aria-labelledby or aria-label props. Component adds an element witharia-live attribute that is only visible to screen readers to read the value displayed. Values to read are defined with the trueLabel, falseLabel and nullLabel keys of the ariaproperty from the locale API. This is an example of a custom accessibility implementation as there is no one to one mapping between the component design and the WCAG specification.
<span id="chkbox1">Remember Me</span>
<TriStateCheckbox aria-labelledby="chkbox1" />
<TriStateCheckbox aria-label="Remember Me" />
Key | Function |
---|---|
tab | Moves focus to the checkbox. |
space | Toggles between the values. |
enter | Toggles between the values. |