devextreme
Version:
HTML5 JavaScript Component Suite for Responsive Web Development
91 lines (90 loc) • 3.04 kB
JavaScript
/**
* DevExtreme (core/utils/array_compare.js)
* Version: 20.1.7
* Build date: Tue Aug 25 2020
*
* Copyright (c) 2012 - 2020 Developer Express Inc. ALL RIGHTS RESERVED
* Read about DevExtreme licensing here: https://js.devexpress.com/Licensing/
*/
;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.findChanges = void 0;
var _type = require("./type");
var getKeyWrapper = function(item, getKey) {
var key = getKey(item);
if ((0, _type.isObject)(key)) {
try {
return JSON.stringify(key)
} catch (e) {
return key
}
}
return key
};
var getSameNewByOld = function(oldItem, newItems, newIndexByKey, getKey) {
var key = getKeyWrapper(oldItem, getKey);
return newItems[newIndexByKey[key]]
};
var findChanges = exports.findChanges = function(oldItems, newItems, getKey, isItemEquals) {
var oldIndexByKey = {};
var newIndexByKey = {};
var addedCount = 0;
var removeCount = 0;
var result = [];
oldItems.forEach(function(item, index) {
var key = getKeyWrapper(item, getKey);
oldIndexByKey[key] = index
});
newItems.forEach(function(item, index) {
var key = getKeyWrapper(item, getKey);
newIndexByKey[key] = index
});
var itemCount = Math.max(oldItems.length, newItems.length);
for (var index = 0; index < itemCount + addedCount; index++) {
var newItem = newItems[index];
var oldNextIndex = index - addedCount + removeCount;
var nextOldItem = oldItems[oldNextIndex];
var isRemoved = !newItem || nextOldItem && !getSameNewByOld(nextOldItem, newItems, newIndexByKey, getKey);
if (isRemoved) {
if (nextOldItem) {
result.push({
type: "remove",
key: getKey(nextOldItem),
index: index,
oldItem: nextOldItem
});
removeCount++;
index--
}
} else {
var key = getKeyWrapper(newItem, getKey);
var oldIndex = oldIndexByKey[key];
var oldItem = oldItems[oldIndex];
if (!oldItem) {
addedCount++;
result.push({
type: "insert",
data: newItem,
index: index
})
} else {
if (oldIndex === oldNextIndex) {
if (!isItemEquals(oldItem, newItem)) {
result.push({
type: "update",
data: newItem,
key: getKey(newItem),
index: index,
oldItem: oldItem
})
}
} else {
return
}
}
}
}
return result
};