| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| /* |
| * The implementation references to d3.js. The use of the source |
| * code of this file is also subject to the terms and consitions |
| * of its license (BSD-3Clause, see <echarts/src/licenses/LICENSE-d3>). |
| */ |
| import * as zrUtil from 'zrender/src/core/util'; |
| /** |
| * nest helper used to group by the array. |
| * can specified the keys and sort the keys. |
| */ |
| |
| export default function nest() { |
| var keysFunction = []; |
| var sortKeysFunction = []; |
| /** |
| * map an Array into the mapObject. |
| * @param {Array} array |
| * @param {number} depth |
| */ |
| |
| function map(array, depth) { |
| if (depth >= keysFunction.length) { |
| return array; |
| } |
| |
| var i = -1; |
| var n = array.length; |
| var keyFunction = keysFunction[depth++]; |
| var mapObject = {}; |
| var valuesByKey = {}; |
| |
| while (++i < n) { |
| var keyValue = keyFunction(array[i]); |
| var values = valuesByKey[keyValue]; |
| |
| if (values) { |
| values.push(array[i]); |
| } else { |
| valuesByKey[keyValue] = [array[i]]; |
| } |
| } |
| |
| zrUtil.each(valuesByKey, function (value, key) { |
| mapObject[key] = map(value, depth); |
| }); |
| return mapObject; |
| } |
| /** |
| * transform the Map Object to multidimensional Array |
| * @param {Object} map |
| * @param {number} depth |
| */ |
| |
| |
| function entriesMap(mapObject, depth) { |
| if (depth >= keysFunction.length) { |
| return mapObject; |
| } |
| |
| var array = []; |
| var sortKeyFunction = sortKeysFunction[depth++]; |
| zrUtil.each(mapObject, function (value, key) { |
| array.push({ |
| key: key, |
| values: entriesMap(value, depth) |
| }); |
| }); |
| |
| if (sortKeyFunction) { |
| return array.sort(function (a, b) { |
| return sortKeyFunction(a.key, b.key); |
| }); |
| } |
| |
| return array; |
| } |
| |
| return { |
| /** |
| * specified the key to groupby the arrays. |
| * users can specified one more keys. |
| * @param {Function} d |
| */ |
| key: function (d) { |
| keysFunction.push(d); |
| return this; |
| }, |
| |
| /** |
| * specified the comparator to sort the keys |
| * @param {Function} order |
| */ |
| sortKeys: function (order) { |
| sortKeysFunction[keysFunction.length - 1] = order; |
| return this; |
| }, |
| |
| /** |
| * the array to be grouped by. |
| * @param {Array} array |
| */ |
| entries: function (array) { |
| return entriesMap(map(array, 0), 0); |
| } |
| }; |
| } |