Command invoker

A simple command invoker, that can be used to implement undo/redo functionality (aka Ctrl+Z / Ctrl+Shift+Z).

Installation

``npm i ts-command-invoker`

Example usage

Command invoker can invoke commands and later undo or redo them. This can be useful for implementing classic undo/redo behavior such as the one you know from Google docs, etc.

`ts
import { Command, CommandInvoker } from 'ts-command-invoker';

let counter = 0;

export class AddOneCommand extends Command {
do(): void {
counter += 1;
}

undo(): void {
counter -= 1;
}
}

const invoker = new CommandInvoker();

invoker.invoke(new AddOneCommand());
// counter === 1

invoker.invoke(new AddOneCommand());
// counter === 2

invoker.undo()
// counter === 1

invoker.undo()
// counter === 0

invoker.redo()
// counter === 1
`

Multiple commands can be batched into one using MultiCommand.

`ts
import { Command, CommandInvoker, MultiCommand } from 'ts-command-invoker';

export class DeleteCommand extends Command {
do(): void {
// delete one item
}

undo(): void {
// bring back one item
}
}

const deleteMultiple = new MultiCommand([
new DeleteCommand(item1),
new DeleteCommand(item2),
]);

const invoker = new CommandInvoker();

invoker.invoke(deleteMultiple);
``

License

Feel free to use in any way. (ISC)

Changelog

- v1.0.3
- Improved Usage example
- v1.0.0
- Command invoker implementation