91 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| 'use strict';
 | |
| 
 | |
| Object.defineProperty(exports, "__esModule", {
 | |
|     value: true
 | |
| });
 | |
| exports.default = seq;
 | |
| 
 | |
| var _noop = require('lodash/noop');
 | |
| 
 | |
| var _noop2 = _interopRequireDefault(_noop);
 | |
| 
 | |
| var _slice = require('./internal/slice');
 | |
| 
 | |
| var _slice2 = _interopRequireDefault(_slice);
 | |
| 
 | |
| var _reduce = require('./reduce');
 | |
| 
 | |
| var _reduce2 = _interopRequireDefault(_reduce);
 | |
| 
 | |
| var _wrapAsync = require('./internal/wrapAsync');
 | |
| 
 | |
| var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
 | |
| 
 | |
| var _arrayMap = require('lodash/_arrayMap');
 | |
| 
 | |
| var _arrayMap2 = _interopRequireDefault(_arrayMap);
 | |
| 
 | |
| function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 | |
| 
 | |
| /**
 | |
|  * Version of the compose function that is more natural to read. Each function
 | |
|  * consumes the return value of the previous function. It is the equivalent of
 | |
|  * [compose]{@link module:ControlFlow.compose} with the arguments reversed.
 | |
|  *
 | |
|  * Each function is executed with the `this` binding of the composed function.
 | |
|  *
 | |
|  * @name seq
 | |
|  * @static
 | |
|  * @memberOf module:ControlFlow
 | |
|  * @method
 | |
|  * @see [async.compose]{@link module:ControlFlow.compose}
 | |
|  * @category Control Flow
 | |
|  * @param {...AsyncFunction} functions - the asynchronous functions to compose
 | |
|  * @returns {Function} a function that composes the `functions` in order
 | |
|  * @example
 | |
|  *
 | |
|  * // Requires lodash (or underscore), express3 and dresende's orm2.
 | |
|  * // Part of an app, that fetches cats of the logged user.
 | |
|  * // This example uses `seq` function to avoid overnesting and error
 | |
|  * // handling clutter.
 | |
|  * app.get('/cats', function(request, response) {
 | |
|  *     var User = request.models.User;
 | |
|  *     async.seq(
 | |
|  *         _.bind(User.get, User),  // 'User.get' has signature (id, callback(err, data))
 | |
|  *         function(user, fn) {
 | |
|  *             user.getCats(fn);      // 'getCats' has signature (callback(err, data))
 | |
|  *         }
 | |
|  *     )(req.session.user_id, function (err, cats) {
 | |
|  *         if (err) {
 | |
|  *             console.error(err);
 | |
|  *             response.json({ status: 'error', message: err.message });
 | |
|  *         } else {
 | |
|  *             response.json({ status: 'ok', message: 'Cats found', data: cats });
 | |
|  *         }
 | |
|  *     });
 | |
|  * });
 | |
|  */
 | |
| function seq() /*...functions*/{
 | |
|     var _functions = (0, _arrayMap2.default)(arguments, _wrapAsync2.default);
 | |
|     return function () /*...args*/{
 | |
|         var args = (0, _slice2.default)(arguments);
 | |
|         var that = this;
 | |
| 
 | |
|         var cb = args[args.length - 1];
 | |
|         if (typeof cb == 'function') {
 | |
|             args.pop();
 | |
|         } else {
 | |
|             cb = _noop2.default;
 | |
|         }
 | |
| 
 | |
|         (0, _reduce2.default)(_functions, args, function (newargs, fn, cb) {
 | |
|             fn.apply(that, newargs.concat(function (err /*, ...nextargs*/) {
 | |
|                 var nextargs = (0, _slice2.default)(arguments, 1);
 | |
|                 cb(err, nextargs);
 | |
|             }));
 | |
|         }, function (err, results) {
 | |
|             cb.apply(that, [err].concat(results));
 | |
|         });
 | |
|     };
 | |
| }
 | |
| module.exports = exports['default']; |