`goForward`

The goForward method moves the state of the underlying Store forwards to a future checkpoint, effectively performing an 'redo' on the Store data.

goForward(): Checkpoints

returns

returns	`Checkpoints`	A reference to the `Checkpoints` object.

Checkpoints

A reference to the Checkpoints object.

If there is no future checkpoint to return to, this method has no effect.

Note that if you have previously used the goBackward method to undo changes, the forwards 'redo' stack will only exist while you do not make changes to the Store. In general the goForward method is expected to be used to redo changes that were just undone.

Examples

This example creates a Store, a Checkpoints object, makes a change and then goes backward to the state of the Store before the change. It then goes forward again to restore the state with the changes.

import {createCheckpoints, createStore} from 'tinybase';

const store = createStore().setTables({pets: {fido: {sold: false}}});

const checkpoints = createCheckpoints(store);
console.log(checkpoints.getCheckpointIds());
// -> [[], '0', []]

store.setCell('pets', 'fido', 'sold', true);
checkpoints.addCheckpoint('sale');
console.log(checkpoints.getCheckpointIds());
// -> [['0'], '1', []]

checkpoints.goBackward();
console.log(store.getCell('pets', 'fido', 'sold'));
// -> false
console.log(checkpoints.getCheckpointIds());
// -> [[], '0', ['1']]

checkpoints.goForward();
console.log(store.getCell('pets', 'fido', 'sold'));
// -> true
console.log(checkpoints.getCheckpointIds());
// -> [['0'], '1', []]

This example creates a Store, a Checkpoints object, makes a change and then goes backward to the state of the Store before the change. It makes a new change, the redo stack disappears, and then the attempt to forward again has no effect.

import {createCheckpoints, createStore} from 'tinybase';

const store = createStore().setTables({pets: {fido: {sold: false}}});

const checkpoints = createCheckpoints(store);
console.log(checkpoints.getCheckpointIds());
// -> [[], '0', []]

store.setCell('pets', 'fido', 'sold', true);
checkpoints.addCheckpoint('sale');
console.log(checkpoints.getCheckpointIds());
// -> [['0'], '1', []]

checkpoints.goBackward();
console.log(store.getCell('pets', 'fido', 'sold'));
// -> false
console.log(checkpoints.getCheckpointIds());
// -> [[], '0', ['1']]

store.setCell('pets', 'fido', 'color', 'brown');
console.log(checkpoints.getCheckpointIds());
// -> [['0'], undefined, []]

checkpoints.goForward();
console.log(store.getCell('pets', 'fido', 'sold'));
// -> false
console.log(checkpoints.getCheckpointIds());
// -> [['0'], undefined, []]
// The original change cannot be redone.

Since

v1.0.0