@xailabs/altx/lib/decorators/bindHandlers.js

Flux flavor based on alt.js

'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.default = bindHandlers;

var _decorators = require('alt-utils/lib/decorators');

var _flatten = require('../utils/flatten');

var _flatten2 = _interopRequireDefault(_flatten);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

// TODO clean up and refactor terminoloy, potentially deprecate the old "handlers" system
// (viewActions are now called handlers, e.g. handlerFactory)

/**
 * Decorates a store with any number of action handlers.
 */
function bindHandlers(actions) {
    for (var _len = arguments.length, handlers = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
        handlers[_key - 1] = arguments[_key];
    }

    return function decorateStore(storeClass) {
        // attach bound handler methods to the store class for each handler definition
        (0, _flatten2.default)(handlers).forEach(function (handler) {
            return attachBoundHandler(storeClass, actions[handler.name], handler);
        });
        return storeClass;
    };
}
/**
 * Attaches a single reducer handling to the store.
 *
 * A new handler method will be created on the store class.
 * The handler method invokes the reducer giving it the current store state.
 * It then sets the reducer result as the new store state.
 *
 * If a sideEffect function is defined, it will be called with the signature `{state, prevState, payload}`
 *
 * @param {object} storeClass - The class of the store to be decorated
 * @param {object} action - An altjs action
 * @param {object} handler - An handler object with `{name[, reducer, sideEffect]}`
 */
function attachBoundHandler(storeClass, action, handler) {
    // name is required

    var methodName = '__handle_' + handler.name;

    if (storeClass.prototype[methodName]) throw new Error('Duplicate method "' + methodName + '"');

    /**
     * Handles an action call and sets the next state of the store.
     *
     * @param {any} payload - the single argument that can be specified when calling an action.
     *                      If you need to use more than one argument, use an object with any properties you need.
     */
    storeClass.prototype[methodName] = function handleAction(payload) {

        var reducer = handler.hasOwnProperty('reducer') && handler.reducer;
        var sideEffect = handler.hasOwnProperty('sideEffect') && handler.sideEffect;

        var currentState = this.state;

        // the actual operation: run the reducer and set its result as state
        var nextState = currentState;
        if (reducer) {
            try {
                nextState = reducer(currentState, payload);
            } catch (error) {
                console.error('Error in reducer (' + handler.name + ', ' + handler.name + ')', error);
            }
        }
        if (nextState) {
            this.setState(nextState);
        } else if (reducer) {
            console.warn('reducer "' + handler.name + '" in call "' + handler.name + '" did not return a new state.\n                Either you forgot to return it, or if no state change is required, maybe you should use a sideEffect instead of a reducer.\n            ');
        }

        if (sideEffect) {
            try {
                sideEffect({ state: nextState, prevState: currentState, payload: payload });
            } catch (error) {
                console.error('Error in sideEffect (' + handler.name + ', ' + handler.name + ')', error);
            }
        }
    };

    var bindhandler = (0, _decorators.bind)(action);

    bindhandler(storeClass, methodName, Object.getOwnPropertyDescriptor(storeClass.prototype, methodName));
};