Package Exports

@rooks/use-undo-state

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Readme

@rooks/use-undo-state

TitleCard

About

Drop in replacement for useState hook but with undo functionality.

Installation

npm install --save @rooks/use-undo-state

Importing the hook

import useUndoState from '@rooks/use-undo-state'

Usage

const Demo = () => {
  const [value, setValue, undo] = useUndoState(0)

  return (
    <div>
      <span>Current value: {value}</span>
      <button onClick={() => setValue(value + 1)}>
        Increment
      </button>
      <button onClick={undo}>
        Undo
      </button>
    </div>
  )
}

render(<Demo/>)

You can pass any kind of value to hook just like React's own useState.

const Demo = () => {
  const [value, setValue, undo] = useUndoState({ data: 42 })

  return (
    <div>
      <span>Current value: {value}</span>
      <button onClick={() => setValue({ data: value.data + 1 })}>
        Increment object data
      </button>
      <button onClick={undo}>
        Undo
      </button>
    </div>
  )
}

render(<Demo/>)

Setter function can also be used with callback just like React's own useState.

const [value, setValue, undo] = useUndoState({ data: 42 })

() => setValue(current => current + 1)

const Demo = () => {
  const [value, setValue, undo] = useUndoState(0)

  return (
    <div>
      <span>Current value: {value}</span>
      <button onClick={() => setValue(current => current + 1)}>
        Increment
      </button>
      <button onClick={undo}>
        Undo
      </button>
    </div>
  )
}

render(<Demo/>)

To preserve memory you can limit number of steps that will be preserved in undo history.

const [value, setValue, undo] = useUndoState(0, { maxSize: 30 })

// now when calling undo only last 30 changes to the value will be preserved

Arguments

Arguments	Type	Description	Default value
initialValue	boolean	Initial value of the state	false
Options	Object	An options object for the hook	{maxSize: 100}

Note: The second argument is an options object which currently accepts a maxSize which governs the maximum number of previous states to keep track of.

Returned array items

Returned Array items	Type	Description
value	Any	Current value
setValue	function	Setter function to update value
undo	function	Undo state value