README

easy-redux-undo

Literally the easiest redux undo/redo library. In addition to being easy, we also offer a collection of great features that you will use all the time!

Feature-list

Holds past/future history
Stores actions as diffs intead of storing the whole state
Can dispatch multiple undo/redos as a single action
Able to clear history
Actions can be undo/redo'd as a group
Can include/exclude actions from being undo/redo-able
Configurable options (max history limit, custom action names, etc.)
Just works out of the box

How to use

npm i easy-redux-undo

Then, add undoable to a reducer:

import undoable from "easy-redux-undo";
import counterReducer from "path/to/reducer/counterReducer";

const createRootReducer =>
  undoable: undoable(
      counter: counterReducer
  )
});

export default createRootReducer;

Finally, update your component with actions to dispatch. See this sample component below that uses some of the libraries' features:

import React from "react";
import { connect } from "react-redux";
import { UNDO, REDO, CLEAR, GROUPBEGIN, GROUPEND } from "easy-redux-undo";
import { increment, decrement } from "path/to/reducer/counterReducer";

class MyComponent extends React.Component {
  constructor() {
    super();

    // Counter-specific
    this.inc = this.inc.bind(this);
    this.dec = this.dec.bind(this);

    // Undo-specific
    this.undo = this.undo.bind(this);
    this.redo = this.redo.bind(this);
    this.undoX = this.undoX.bind(this);
    this.redoX = this.redoX.bind(this);
    this.groupbegin = this.groupbegin.bind(this);
    this.groupend = this.groupend.bind(this);
    this.clear = this.clear.bind(this);
  }

  // Increments counter
  inc() {
    this.props.increment();
  }

  // Decrements counter
  dec() {
    this.props.decrement();
  }

  // Undos last action
  undo() {
    this.props.UNDO();
  }

  // Redos last action
  redo() {
    this.props.REDO();
  }

  // Undos x amount of actions
  undoX(count) {
    this.props.UNDO(count);
  }

  // Redos x amount of actions
  redoX(count) {
    this.props.REDO(count);
  }

  // Begins a group
  groupbegin(){
    this.props.GROUPBEGIN();
  }

  // Ends a group
  groupend(){
    this.props.GROUPEND();
  }

  // Clears all history
  clear(){
    this.props.CLEAR();
  }

  render() {
    return (
      <div>
        <h4>Undo/Redo</h4>
        <span>
          Try out modifying, and then undo/redoing the redux history below!
        </span>
        <div>
          <h3>Counter</h3>
          {this.props.counter.value}
          <div>
            <button onClick={this.dec}>dec</button>
            <button onClick={this.inc}>inc</button>
          </div>
        </div>
        <button onClick={() => this.undoX(2)}>undo 2</button>
        <button onClick={this.undo}>undo</button>
        <button onClick={this.redo}>redo</button>
        <button onClick={() => this.redoX(2)}>redo 2</button>
        <button onClick={this.groupbegin}>group begin</button>
        <button onClick={this.groupend}>group end</button>
        <button onClick={this.clear}>clear</button>
      </div>
    );
  }
}

const mapStateToProps = (state, props) => ({
  counter: state.undoable.present.counter
});
const mapDispatch = { increment, decrement, UNDO, REDO, GROUPBEGIN, GROUPEND };

export default connect(mapStateToProps, mapDispatch)(MyComponent);

You are done! ✔️

FAQ

Why do I need to include `.present` in my component?

The reducer creates 3 properties in which your current state (ie. present) and past/future (ie. past/future) actions live, it's necessary to grab the value from the present property in your components.

See a sample of modifications you will need to make before/after using this library: BEFORE

const mapStateToProps = (state, props) => ({
  counter: state.undoable.counter
});

AFTER

const mapStateToProps = (state, props) => ({
  counter: state.undoable.present.counter
});

What do you mean by "Stores actions as diffs intead of storing the whole state"?

Libraries such as (the popular) redux-undo library stores actions by storing copies of the state in the past and future arrays. This may work for small projects, but quickly becomes unscalable when making any real app.

This library uses deep-diff to create diffs whenever an action is made, this makes undo/redoing actions much more efficient.

If you don't end up using this library, be sure your library stores actions as diffs instead of the entire state!

What do you mean by "Actions can be undo/redo'd as a group"?

Say you have an application that has a few different actions, and you want these actions to be undo/redo-able in a group. For this example, let's assume that the actions are SWITCH_TAB, SORT_LIST and TOGGLE_SETTING. Upon clicking your "undo" button in the UI, these actions should be undone in a group.

To do this, you can send dispatch a GROUPBEGIN action before you send your other actions, and a GROUPEND action once you are done. You'll be able to undo all 3 actions at once (in the sequence they were dispatched).

If we were using the above example that would be something like this:

this.props.GROUPBEGIN(); // begin group
this.props.SWITCHTAB();
this.props.SORTLIST();
this.props.TOGGLESETTING();
this.props.GROUPEND(); // end group; all actions are now in one undo-able action

How do I include/exclude actions from being undo/redo-able?

Sometimes, you may want to include/exclude certain actions from being undo/redo-able. To configure these actions, simply update the include or exclude properties on the options object you can pass in when configuring the reducer.

Don't include both the include and exclude properties or you'll get an error!

Here's an example:

import undoable from "easy-redux-undo";
import counterReducer from "path/to/reducer/counterReducer";

const createRootReducer =>
  undoable: undoable(
      counter: counterReducer
  , {
      include: [
          "REDUCER/MYACTION1",
          "REDUCER/MYACTION2"
      ]
  })
});

export default createRootReducer;

Or, an example of excluding actions:

import undoable from "easy-redux-undo";
import counterReducer from "path/to/reducer/counterReducer";

const createRootReducer =>
  undoable: undoable(
      counter: counterReducer
  , {
      exclude: [
          "REDUCER/MYACTION3",
          "REDUCER/MYACTION4"
      ]
  })
});

export default createRootReducer;

What options do we have for configuring the reducer?

You can pass in any of these values to configure the reducer, all of the values seen below are defaults.

Additionally, you see below that you can change the limit of actions that are saved in the undo/redo history through the maxHistory property.

{
    maxHistory: 100,
    undoType: "@@easy-redux-undo/UNDO",
    redoType: "@@easy-redux-undo/REDO",
    clearType: "@@easy-redux-undo/CLEAR",
    groupBeginType: "@@easy-redux-undo/GROUPBEGIN",
    groupEndType: "@@easy-redux-undo/GROUPEND",
    include: [],
    exclude: []
}

How do I actually configure the reducer in a production app?

Too often, the samples we (including me) give to configure the reducer aren't enough. Apps are complicated, and so should the example. Here's a more-complete example of what your reducer might look like.

The below sample has a few things, namely an HTML history, and at least once reducer that is not undoable (the home reducer).

PS - this is taken out of secure-electron-template (the template this library was built to use).

import { combineReducers } from "redux";
import { connectRouter } from "connected-react-router";
import undoable from "easy-redux-undo";
import homeReducer from "../components/home/homeSlice";
import counterReducer from "../components/counter/counterSlice";
import complexReducer from "../components/complex/complexSlice";

const createRootReducer = (history) =>
  combineReducers({
    router: connectRouter(history),
    home: homeReducer,
    undoable: undoable(
      combineReducers({
        counter: counterReducer,
        complex: complexReducer
      })
    )
  });

export default createRootReducer;

Usage no npm install needed!