Unstyled form control
The FormControlUnstyled is a utility that lets you associate a form input with auxillary components, such as labels, error indicators or helper text.
FormControlUnstyled
FormControlUnstyled wraps an input and other components, enabling to reflect the input's state in these other components.
For instance, you may want to show an additional element asking the user to enter a value if the input is empty, or display a warning icon if the entered value is incorrect.
Name *
<FormControlUnstyled defaultValue="" required>
<Label>Name</Label>
<Input />
<HelperText />
</FormControlUnstyled>
The FormControlUnstyled provides a context that can be read by the useFormControl hook.
useFormControl hook
The useFormControl hook can be used to enable integration between custom form inputs and FormControlUnstyled. Additionally, you can read the form control's state and react to its changes in a custom component.
The demo below shows both. CustomInput
is a wrapper around a native HTML input
that adds FormControlUnstyled integration. ControlStateDisplay
reads the state of the form control and displays it as text.
empty | not focused
Note that even though FormControlUnstyled supports both controlled and uncontrolled-style API (i.e. it accepts value
and defaultValue
props), useFormControl
returns only the controlled value
. This way, you don't have to implement both in your custom input - FormControlUnstyled does this for you.
useFormControl
returns an object with the following fields:
Name | Type | Description |
---|---|---|
disabled |
boolean | Represents the value of the FormControlUnstyled's disabled prop. |
error |
boolean | Represents the value of the FormControlUnstyled's error prop. Note that it is not calculated automatically (i.e. it's not set when required: true and value: '' ) |
filled |
boolean | Set to true if value is not empty. |
focused |
boolean | Set to true if the wrapped input has received focus. |
required |
boolean | Represents the value of the FormControlUnstyled's required prop. |
value |
unknown | The current value of the form control. |
Additionally, the following callbacks are a part of the returned object. They are meant to be used when creating custom inputs.
Name | Type | Description |
---|---|---|
onChange |
React.ChangeEvent => void | Value change handler. Should be forwarded to the inner input. |
onBlur |
() => void | Focus change handler. Should be forwarded to the inner input. |
onFocus |
() => void | Focus change handler. Should be forwarded to the inner input. |