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					170 lines
				
				6.3 KiB
			
		
		
			
		
	
	
					170 lines
				
				6.3 KiB
			| 
											3 years ago
										 | 'use strict'; | ||
|  | 
 | ||
|  | Object.defineProperty(exports, "__esModule", { | ||
|  |     value: true | ||
|  | }); | ||
|  | exports.default = autoInject; | ||
|  | 
 | ||
|  | var _auto = require('./auto'); | ||
|  | 
 | ||
|  | var _auto2 = _interopRequireDefault(_auto); | ||
|  | 
 | ||
|  | var _baseForOwn = require('lodash/_baseForOwn'); | ||
|  | 
 | ||
|  | var _baseForOwn2 = _interopRequireDefault(_baseForOwn); | ||
|  | 
 | ||
|  | var _arrayMap = require('lodash/_arrayMap'); | ||
|  | 
 | ||
|  | var _arrayMap2 = _interopRequireDefault(_arrayMap); | ||
|  | 
 | ||
|  | var _isArray = require('lodash/isArray'); | ||
|  | 
 | ||
|  | var _isArray2 = _interopRequireDefault(_isArray); | ||
|  | 
 | ||
|  | var _trim = require('lodash/trim'); | ||
|  | 
 | ||
|  | var _trim2 = _interopRequireDefault(_trim); | ||
|  | 
 | ||
|  | var _wrapAsync = require('./internal/wrapAsync'); | ||
|  | 
 | ||
|  | var _wrapAsync2 = _interopRequireDefault(_wrapAsync); | ||
|  | 
 | ||
|  | function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } | ||
|  | 
 | ||
|  | var FN_ARGS = /^(?:async\s+)?(function)?\s*[^\(]*\(\s*([^\)]*)\)/m; | ||
|  | var FN_ARG_SPLIT = /,/; | ||
|  | var FN_ARG = /(=.+)?(\s*)$/; | ||
|  | var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg; | ||
|  | 
 | ||
|  | function parseParams(func) { | ||
|  |     func = func.toString().replace(STRIP_COMMENTS, ''); | ||
|  |     func = func.match(FN_ARGS)[2].replace(' ', ''); | ||
|  |     func = func ? func.split(FN_ARG_SPLIT) : []; | ||
|  |     func = func.map(function (arg) { | ||
|  |         return (0, _trim2.default)(arg.replace(FN_ARG, '')); | ||
|  |     }); | ||
|  |     return func; | ||
|  | } | ||
|  | 
 | ||
|  | /** | ||
|  |  * A dependency-injected version of the [async.auto]{@link module:ControlFlow.auto} function. Dependent | ||
|  |  * tasks are specified as parameters to the function, after the usual callback | ||
|  |  * parameter, with the parameter names matching the names of the tasks it | ||
|  |  * depends on. This can provide even more readable task graphs which can be | ||
|  |  * easier to maintain. | ||
|  |  * | ||
|  |  * If a final callback is specified, the task results are similarly injected, | ||
|  |  * specified as named parameters after the initial error parameter. | ||
|  |  * | ||
|  |  * The autoInject function is purely syntactic sugar and its semantics are | ||
|  |  * otherwise equivalent to [async.auto]{@link module:ControlFlow.auto}. | ||
|  |  * | ||
|  |  * @name autoInject | ||
|  |  * @static | ||
|  |  * @memberOf module:ControlFlow | ||
|  |  * @method | ||
|  |  * @see [async.auto]{@link module:ControlFlow.auto} | ||
|  |  * @category Control Flow | ||
|  |  * @param {Object} tasks - An object, each of whose properties is an {@link AsyncFunction} of | ||
|  |  * the form 'func([dependencies...], callback). The object's key of a property | ||
|  |  * serves as the name of the task defined by that property, i.e. can be used | ||
|  |  * when specifying requirements for other tasks. | ||
|  |  * * The `callback` parameter is a `callback(err, result)` which must be called | ||
|  |  *   when finished, passing an `error` (which can be `null`) and the result of | ||
|  |  *   the function's execution. The remaining parameters name other tasks on | ||
|  |  *   which the task is dependent, and the results from those tasks are the | ||
|  |  *   arguments of those parameters. | ||
|  |  * @param {Function} [callback] - An optional callback which is called when all | ||
|  |  * the tasks have been completed. It receives the `err` argument if any `tasks` | ||
|  |  * pass an error to their callback, and a `results` object with any completed | ||
|  |  * task results, similar to `auto`. | ||
|  |  * @example | ||
|  |  * | ||
|  |  * //  The example from `auto` can be rewritten as follows:
 | ||
|  |  * async.autoInject({ | ||
|  |  *     get_data: function(callback) { | ||
|  |  *         // async code to get some data
 | ||
|  |  *         callback(null, 'data', 'converted to array'); | ||
|  |  *     }, | ||
|  |  *     make_folder: function(callback) { | ||
|  |  *         // async code to create a directory to store a file in
 | ||
|  |  *         // this is run at the same time as getting the data
 | ||
|  |  *         callback(null, 'folder'); | ||
|  |  *     }, | ||
|  |  *     write_file: function(get_data, make_folder, callback) { | ||
|  |  *         // once there is some data and the directory exists,
 | ||
|  |  *         // write the data to a file in the directory
 | ||
|  |  *         callback(null, 'filename'); | ||
|  |  *     }, | ||
|  |  *     email_link: function(write_file, callback) { | ||
|  |  *         // once the file is written let's email a link to it...
 | ||
|  |  *         // write_file contains the filename returned by write_file.
 | ||
|  |  *         callback(null, {'file':write_file, 'email':'user@example.com'}); | ||
|  |  *     } | ||
|  |  * }, function(err, results) { | ||
|  |  *     console.log('err = ', err); | ||
|  |  *     console.log('email_link = ', results.email_link); | ||
|  |  * }); | ||
|  |  * | ||
|  |  * // If you are using a JS minifier that mangles parameter names, `autoInject`
 | ||
|  |  * // will not work with plain functions, since the parameter names will be
 | ||
|  |  * // collapsed to a single letter identifier.  To work around this, you can
 | ||
|  |  * // explicitly specify the names of the parameters your task function needs
 | ||
|  |  * // in an array, similar to Angular.js dependency injection.
 | ||
|  |  * | ||
|  |  * // This still has an advantage over plain `auto`, since the results a task
 | ||
|  |  * // depends on are still spread into arguments.
 | ||
|  |  * async.autoInject({ | ||
|  |  *     //...
 | ||
|  |  *     write_file: ['get_data', 'make_folder', function(get_data, make_folder, callback) { | ||
|  |  *         callback(null, 'filename'); | ||
|  |  *     }], | ||
|  |  *     email_link: ['write_file', function(write_file, callback) { | ||
|  |  *         callback(null, {'file':write_file, 'email':'user@example.com'}); | ||
|  |  *     }] | ||
|  |  *     //...
 | ||
|  |  * }, function(err, results) { | ||
|  |  *     console.log('err = ', err); | ||
|  |  *     console.log('email_link = ', results.email_link); | ||
|  |  * }); | ||
|  |  */ | ||
|  | function autoInject(tasks, callback) { | ||
|  |     var newTasks = {}; | ||
|  | 
 | ||
|  |     (0, _baseForOwn2.default)(tasks, function (taskFn, key) { | ||
|  |         var params; | ||
|  |         var fnIsAsync = (0, _wrapAsync.isAsync)(taskFn); | ||
|  |         var hasNoDeps = !fnIsAsync && taskFn.length === 1 || fnIsAsync && taskFn.length === 0; | ||
|  | 
 | ||
|  |         if ((0, _isArray2.default)(taskFn)) { | ||
|  |             params = taskFn.slice(0, -1); | ||
|  |             taskFn = taskFn[taskFn.length - 1]; | ||
|  | 
 | ||
|  |             newTasks[key] = params.concat(params.length > 0 ? newTask : taskFn); | ||
|  |         } else if (hasNoDeps) { | ||
|  |             // no dependencies, use the function as-is
 | ||
|  |             newTasks[key] = taskFn; | ||
|  |         } else { | ||
|  |             params = parseParams(taskFn); | ||
|  |             if (taskFn.length === 0 && !fnIsAsync && params.length === 0) { | ||
|  |                 throw new Error("autoInject task functions require explicit parameters."); | ||
|  |             } | ||
|  | 
 | ||
|  |             // remove callback param
 | ||
|  |             if (!fnIsAsync) params.pop(); | ||
|  | 
 | ||
|  |             newTasks[key] = params.concat(newTask); | ||
|  |         } | ||
|  | 
 | ||
|  |         function newTask(results, taskCb) { | ||
|  |             var newArgs = (0, _arrayMap2.default)(params, function (name) { | ||
|  |                 return results[name]; | ||
|  |             }); | ||
|  |             newArgs.push(taskCb); | ||
|  |             (0, _wrapAsync2.default)(taskFn).apply(null, newArgs); | ||
|  |         } | ||
|  |     }); | ||
|  | 
 | ||
|  |     (0, _auto2.default)(newTasks, callback); | ||
|  | } | ||
|  | module.exports = exports['default']; |