; | |
Object.defineProperty(exports, "__esModule", { | |
value: true | |
}); | |
var _map = require('./map.js'); | |
var _map2 = _interopRequireDefault(_map); | |
var _wrapAsync = require('./internal/wrapAsync.js'); | |
var _wrapAsync2 = _interopRequireDefault(_wrapAsync); | |
var _awaitify = require('./internal/awaitify.js'); | |
var _awaitify2 = _interopRequireDefault(_awaitify); | |
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } | |
/** | |
* Sorts a list by the results of running each `coll` value through an async | |
* `iteratee`. | |
* | |
* @name sortBy | |
* @static | |
* @memberOf module:Collections | |
* @method | |
* @category Collection | |
* @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. | |
* @param {AsyncFunction} iteratee - An async function to apply to each item in | |
* `coll`. | |
* The iteratee should complete with a value to use as the sort criteria as | |
* its `result`. | |
* Invoked with (item, callback). | |
* @param {Function} callback - A callback which is called after all the | |
* `iteratee` functions have finished, or an error occurs. Results is the items | |
* from the original `coll` sorted by the values returned by the `iteratee` | |
* calls. Invoked with (err, results). | |
* @returns {Promise} a promise, if no callback passed | |
* @example | |
* | |
* // bigfile.txt is a file that is 251100 bytes in size | |
* // mediumfile.txt is a file that is 11000 bytes in size | |
* // smallfile.txt is a file that is 121 bytes in size | |
* | |
* // asynchronous function that returns the file size in bytes | |
* function getFileSizeInBytes(file, callback) { | |
* fs.stat(file, function(err, stat) { | |
* if (err) { | |
* return callback(err); | |
* } | |
* callback(null, stat.size); | |
* }); | |
* } | |
* | |
* // Using callbacks | |
* async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes, | |
* function(err, results) { | |
* if (err) { | |
* console.log(err); | |
* } else { | |
* console.log(results); | |
* // results is now the original array of files sorted by | |
* // file size (ascending by default), e.g. | |
* // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] | |
* } | |
* } | |
* ); | |
* | |
* // By modifying the callback parameter the | |
* // sorting order can be influenced: | |
* | |
* // ascending order | |
* async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], function(file, callback) { | |
* getFileSizeInBytes(file, function(getFileSizeErr, fileSize) { | |
* if (getFileSizeErr) return callback(getFileSizeErr); | |
* callback(null, fileSize); | |
* }); | |
* }, function(err, results) { | |
* if (err) { | |
* console.log(err); | |
* } else { | |
* console.log(results); | |
* // results is now the original array of files sorted by | |
* // file size (ascending by default), e.g. | |
* // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] | |
* } | |
* } | |
* ); | |
* | |
* // descending order | |
* async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], function(file, callback) { | |
* getFileSizeInBytes(file, function(getFileSizeErr, fileSize) { | |
* if (getFileSizeErr) { | |
* return callback(getFileSizeErr); | |
* } | |
* callback(null, fileSize * -1); | |
* }); | |
* }, function(err, results) { | |
* if (err) { | |
* console.log(err); | |
* } else { | |
* console.log(results); | |
* // results is now the original array of files sorted by | |
* // file size (ascending by default), e.g. | |
* // [ 'bigfile.txt', 'mediumfile.txt', 'smallfile.txt'] | |
* } | |
* } | |
* ); | |
* | |
* // Error handling | |
* async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes, | |
* function(err, results) { | |
* if (err) { | |
* console.log(err); | |
* // [ Error: ENOENT: no such file or directory ] | |
* } else { | |
* console.log(results); | |
* } | |
* } | |
* ); | |
* | |
* // Using Promises | |
* async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes) | |
* .then( results => { | |
* console.log(results); | |
* // results is now the original array of files sorted by | |
* // file size (ascending by default), e.g. | |
* // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] | |
* }).catch( err => { | |
* console.log(err); | |
* }); | |
* | |
* // Error handling | |
* async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes) | |
* .then( results => { | |
* console.log(results); | |
* }).catch( err => { | |
* console.log(err); | |
* // [ Error: ENOENT: no such file or directory ] | |
* }); | |
* | |
* // Using async/await | |
* (async () => { | |
* try { | |
* let results = await async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes); | |
* console.log(results); | |
* // results is now the original array of files sorted by | |
* // file size (ascending by default), e.g. | |
* // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] | |
* } | |
* catch (err) { | |
* console.log(err); | |
* } | |
* })(); | |
* | |
* // Error handling | |
* async () => { | |
* try { | |
* let results = await async.sortBy(['missingfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes); | |
* console.log(results); | |
* } | |
* catch (err) { | |
* console.log(err); | |
* // [ Error: ENOENT: no such file or directory ] | |
* } | |
* } | |
* | |
*/ | |
function sortBy(coll, iteratee, callback) { | |
var _iteratee = (0, _wrapAsync2.default)(iteratee); | |
return (0, _map2.default)(coll, (x, iterCb) => { | |
_iteratee(x, (err, criteria) => { | |
if (err) return iterCb(err); | |
iterCb(err, { value: x, criteria }); | |
}); | |
}, (err, results) => { | |
if (err) return callback(err); | |
callback(null, results.sort(comparator).map(v => v.value)); | |
}); | |
function comparator(left, right) { | |
var a = left.criteria, | |
b = right.criteria; | |
return a < b ? -1 : a > b ? 1 : 0; | |
} | |
} | |
exports.default = (0, _awaitify2.default)(sortBy, 3); | |
module.exports = exports.default; |