| OLD | NEW |
| (Empty) | |
| 1 <!-- |
| 2 @license |
| 3 Copyright (c) 2017 The Polymer Project Authors. All rights reserved. |
| 4 This code may only be used under the BSD style license found at http://polymer.g
ithub.io/LICENSE.txt |
| 5 The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt |
| 6 The complete set of contributors may be found at http://polymer.github.io/CONTRI
BUTORS.txt |
| 7 Code distributed by Google as part of the polymer project is also |
| 8 subject to an additional IP rights grant found at http://polymer.github.io/PATEN
TS.txt |
| 9 --> |
| 10 |
| 11 <link rel="import" href="../mixins/mutable-data.html"> |
| 12 |
| 13 <script> |
| 14 (function() { |
| 15 'use strict'; |
| 16 |
| 17 let mutablePropertyChange = Polymer.MutableData._mutablePropertyChange; |
| 18 |
| 19 /** |
| 20 * Legacy element behavior to skip strict dirty-checking for objects and array
s, |
| 21 * (always consider them to be "dirty") for use on legacy API Polymer elements
. |
| 22 * |
| 23 * By default, `Polymer.PropertyEffects` performs strict dirty checking on |
| 24 * objects, which means that any deep modifications to an object or array will |
| 25 * not be propagated unless "immutable" data patterns are used (i.e. all objec
t |
| 26 * references from the root to the mutation were changed). |
| 27 * |
| 28 * Polymer also provides a proprietary data mutation and path notification API |
| 29 * (e.g. `notifyPath`, `set`, and array mutation API's) that allow efficient |
| 30 * mutation and notification of deep changes in an object graph to all element
s |
| 31 * bound to the same object graph. |
| 32 * |
| 33 * In cases where neither immutable patterns nor the data mutation API can be |
| 34 * used, applying this mixin will cause Polymer to skip dirty checking for |
| 35 * objects and arrays (always consider them to be "dirty"). This allows a |
| 36 * user to make a deep modification to a bound object graph, and then either |
| 37 * simply re-set the object (e.g. `this.items = this.items`) or call `notifyPa
th` |
| 38 * (e.g. `this.notifyPath('items')`) to update the tree. Note that all |
| 39 * elements that wish to be updated based on deep mutations must apply this |
| 40 * mixin or otherwise skip strict dirty checking for objects/arrays. |
| 41 * |
| 42 * In order to make the dirty check strategy configurable, see |
| 43 * `Polymer.OptionalMutableDataBehavior`. |
| 44 * |
| 45 * Note, the performance characteristics of propagating large object graphs |
| 46 * will be worse as opposed to using strict dirty checking with immutable |
| 47 * patterns or Polymer's path notification API. |
| 48 * |
| 49 * @polymerBehavior |
| 50 * @memberof Polymer |
| 51 * @summary Behavior to skip strict dirty-checking for objects and |
| 52 * arrays |
| 53 */ |
| 54 Polymer.MutableDataBehavior = { |
| 55 |
| 56 /** |
| 57 * Overrides `Polymer.PropertyEffects` to provide option for skipping |
| 58 * strict equality checking for Objects and Arrays. |
| 59 * |
| 60 * This method pulls the value to dirty check against from the `__dataTemp` |
| 61 * cache (rather than the normal `__data` cache) for Objects. Since the tem
p |
| 62 * cache is cleared at the end of a turn, this implementation allows |
| 63 * side-effects of deep object changes to be processed by re-setting the |
| 64 * same object (using the temp cache as an in-turn backstop to prevent |
| 65 * cycles due to 2-way notification). |
| 66 * |
| 67 * @param {string} property Property name |
| 68 * @param {*} value New property value |
| 69 * @param {*} old Previous property value |
| 70 * @return {boolean} Whether the property should be considered a change |
| 71 * @protected |
| 72 */ |
| 73 _shouldPropertyChange(property, value, old) { |
| 74 return mutablePropertyChange(this, property, value, old, true); |
| 75 } |
| 76 }; |
| 77 |
| 78 /** |
| 79 * Legacy element behavior to add the optional ability to skip strict |
| 80 * dirty-checking for objects and arrays (always consider them to be |
| 81 * "dirty") by setting a `mutable-data` attribute on an element instance. |
| 82 * |
| 83 * By default, `Polymer.PropertyEffects` performs strict dirty checking on |
| 84 * objects, which means that any deep modifications to an object or array will |
| 85 * not be propagated unless "immutable" data patterns are used (i.e. all objec
t |
| 86 * references from the root to the mutation were changed). |
| 87 * |
| 88 * Polymer also provides a proprietary data mutation and path notification API |
| 89 * (e.g. `notifyPath`, `set`, and array mutation API's) that allow efficient |
| 90 * mutation and notification of deep changes in an object graph to all element
s |
| 91 * bound to the same object graph. |
| 92 * |
| 93 * In cases where neither immutable patterns nor the data mutation API can be |
| 94 * used, applying this mixin will allow Polymer to skip dirty checking for |
| 95 * objects and arrays (always consider them to be "dirty"). This allows a |
| 96 * user to make a deep modification to a bound object graph, and then either |
| 97 * simply re-set the object (e.g. `this.items = this.items`) or call `notifyPa
th` |
| 98 * (e.g. `this.notifyPath('items')`) to update the tree. Note that all |
| 99 * elements that wish to be updated based on deep mutations must apply this |
| 100 * mixin or otherwise skip strict dirty checking for objects/arrays. |
| 101 * |
| 102 * While this behavior adds the ability to forgo Object/Array dirty checking, |
| 103 * the `mutableData` flag defaults to false and must be set on the instance. |
| 104 * |
| 105 * Note, the performance characteristics of propagating large object graphs |
| 106 * will be worse by relying on `mutableData: true` as opposed to using |
| 107 * strict dirty checking with immutable patterns or Polymer's path notificatio
n |
| 108 * API. |
| 109 * |
| 110 * @polymerBehavior |
| 111 * @memberof Polymer |
| 112 * @summary Behavior to optionally skip strict dirty-checking for objects and |
| 113 * arrays |
| 114 */ |
| 115 Polymer.OptionalMutableDataBehavior = { |
| 116 |
| 117 properties: { |
| 118 /** |
| 119 * Instance-level flag for configuring the dirty-checking strategy |
| 120 * for this element. When true, Objects and Arrays will skip dirty |
| 121 * checking, otherwise strict equality checking will be used. |
| 122 */ |
| 123 mutableData: Boolean |
| 124 }, |
| 125 |
| 126 /** |
| 127 * Overrides `Polymer.PropertyEffects` to skip strict equality checking |
| 128 * for Objects and Arrays. |
| 129 * |
| 130 * Pulls the value to dirty check against from the `__dataTemp` cache |
| 131 * (rather than the normal `__data` cache) for Objects. Since the temp |
| 132 * cache is cleared at the end of a turn, this implementation allows |
| 133 * side-effects of deep object changes to be processed by re-setting the |
| 134 * same object (using the temp cache as an in-turn backstop to prevent |
| 135 * cycles due to 2-way notification). |
| 136 * |
| 137 * @param {string} property Property name |
| 138 * @param {*} value New property value |
| 139 * @param {*} old Previous property value |
| 140 * @return {boolean} Whether the property should be considered a change |
| 141 * @protected |
| 142 */ |
| 143 _shouldPropertyChange(property, value, old) { |
| 144 return mutablePropertyChange(this, property, value, old, this.mutableData)
; |
| 145 } |
| 146 }; |
| 147 |
| 148 })(); |
| 149 |
| 150 </script> |
| OLD | NEW |