redux-undo-actions/dist/reducers.js

Redux middleware for undo/redo actions by dispatching reverting action

'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.canRedo = exports.canUndo = exports.getFutureHistoryItem = exports.getPastHistoryItem = undefined;

var _types = require('./types');

var types = _interopRequireWildcard(_types);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }

var defaultState = {
    past: [],
    future: []
};

var undoHistory = function undoHistory() {
    var state = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : defaultState;
    var action = arguments[1];
    var past = state.past,
        future = state.future;

    switch (action.type) {
        case types.HISTORY_UNDO:
            return canUndo(state) ? {
                past: past.slice(0, past.length - action.index),
                future: [].concat(_toConsumableArray(past.slice(past.length - action.index, past.length)), _toConsumableArray(future))
            } : state;
        case types.HISTORY_REDO:
            return canRedo(state) ? {
                past: [].concat(_toConsumableArray(past), _toConsumableArray(future.slice(0, action.index))),
                future: future.slice(action.index, future.length)
            } : state;

        case types.HISTORY_ADD:
            return {
                past: [].concat(_toConsumableArray(past), [{
                    action: action.action,
                    state: action.state
                }]),
                future: []
            };
        case types.HISTORY_CLEAR:
            return {
                past: [],
                future: []
            };
        default:
            return state;
    }
};
var getPastHistoryItem = exports.getPastHistoryItem = function getPastHistoryItem(state) {
    var index = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;
    return state.past[state.past.length - index];
};
var getFutureHistoryItem = exports.getFutureHistoryItem = function getFutureHistoryItem(state) {
    var index = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;
    return state.future[index - 1];
};
var canUndo = exports.canUndo = function canUndo(state) {
    return state.past.length > 0;
};
var canRedo = exports.canRedo = function canRedo(state) {
    return state.future.length > 0;
};

exports.default = undoHistory;