One of my components utilizes useState() to manage the state of its floating label. Here's an example:
const FloatingLabelInput = props => {
const {
value = ''
} = props
const [floatingLabel, toggleFloatingLabel] = useState(value !== '')
Even though I expect initialFloatingLabel and floatingLabel to always be the same, they differ in some instances! Upon logging the values:
const initialFloatingLabel = value !== ''
console.log(initialFloatingLabel) // false
const [floatingLabel, toggleFloatingLabel] = useState(initialFloatingLabel)
console.log(floatingLabel) // true???
This inconsistency persists. How is this possible?
Why does value vary from initialValue in the given scenario? Could this be a form of race condition?
const [value, setValue] = useState(initialValue)
For more information refer to this link
UPDATE
The issue can be resolved by implementing this solution (as suggested):
useEffect(() => setFloatingLabel(initialFloatingLabel), [initialFloatingLabel])
However, a new problem arises: when focusing on a field, typing something, then deleting it until the value becomes empty, it causes the label to "unfloat" (the label should remain floating):
https://i.stack.imgur.com/M4LDh.png
I didn't intend for the floatingLabel state to update based on the input
value</code consistently; rather, the value of <code>initialFloatingLabel</code was intended to determine the toggle's initial value, with toggling occurring during <code>handleBlurhandleChange events like so:
const handleFocus = e => {
toggleFloatingLabel(true)
}
const handleBlur = e => {
if (value === '') {
toggleFloatingLabel(false)
}
}
Is this approach incorrect?
UPDATE
Despite finding multiple solutions, a persistent issue remains, suggesting a problem with Formik - it seems to render all input components initially before the values are fully computed from Formik's initialValues.
One such modification involves adding another local state which updates during handleFocus and handleBlur:
const [isFocused, setFocused] = useState(false)
This allows preventing the label from "unfloating" when the input is empty but focused through the following logic:
useEffect(() => {
const shouldFloat = value !== '' && !isFocused
setFloatLabel(shouldFloat)
}, [value])
To avoid unnecessary animation transitions for pre-populated fields, you can use:
const [floatLabel, setFloatLabel] = useState(value !== '')
While eliminating the floatingLabel local state altogether as recommended in the comments proves beneficial, ensuring only the isFocused state is retained. Thus, enabling smoother label animations:
const animatedProps = useSpring({
transform: isFocused || value !== '' ? 'translate3d(0,-13px,0) scale(0.66)' : 'translate3d(0,0px,0) scale(1)',
config: {
tension: 350,
},
})
Although streamlining the code, a lingering issue persists where undesired label animations occur due to value !== '' inexplicably equating to true initially and then reverting to false. Is there an error in how Formik handles initial field values?