The Tor Browser / file comparison
comparison: browser/devtools/shared/observable-object.js
browser/devtools/shared/observable-object.js
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| 1 /* this source code form is subject to the terms of the mozilla public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 /** | |
| 6 * ObservableObject | |
| 7 * | |
| 8 * An observable object is a JSON-like object that throws | |
| 9 * events when its direct properties or properties of any | |
| 10 * contained objects, are getting accessed or set. | |
| 11 * | |
| 12 * Inherits from EventEmitter. | |
| 13 * | |
| 14 * Properties: | |
| 15 * ⬩ object: JSON-like object | |
| 16 * | |
| 17 * Events: | |
| 18 * ⬩ "get" / path (array of property names) | |
| 19 * ⬩ "set" / path / new value | |
| 20 * | |
| 21 * Example: | |
| 22 * | |
| 23 * let emitter = new ObservableObject({ x: { y: [10] } }); | |
| 24 * emitter.on("set", console.log); | |
| 25 * emitter.on("get", console.log); | |
| 26 * let obj = emitter.object; | |
| 27 * obj.x.y[0] = 50; | |
| 28 * | |
| 29 */ | |
| 30 | |
| 31 "use strict"; | |
| 32 | |
| 33 const EventEmitter = require("devtools/toolkit/event-emitter"); | |
| 34 | |
| 35 function ObservableObject(object = {}) { | |
| 36 EventEmitter.decorate(this); | |
| 37 let handler = new Handler(this); | |
| 38 this.object = new Proxy(object, handler); | |
| 39 handler._wrappers.set(this.object, object); | |
| 40 handler._paths.set(object, []); | |
| 41 } | |
| 42 | |
| 43 module.exports = ObservableObject; | |
| 44 | |
| 45 function isObject(x) { | |
| 46 if (typeof x === "object") | |
| 47 return x !== null; | |
| 48 return typeof x === "function"; | |
| 49 } | |
| 50 | |
| 51 function Handler(emitter) { | |
| 52 this._emitter = emitter; | |
| 53 this._wrappers = new WeakMap(); | |
| 54 this._values = new WeakMap(); | |
| 55 this._paths = new WeakMap(); | |
| 56 } | |
| 57 | |
| 58 Handler.prototype = { | |
| 59 wrap: function(target, key, value) { | |
| 60 let path; | |
| 61 if (!isObject(value)) { | |
| 62 path = this._paths.get(target).concat(key); | |
| 63 } else if (this._wrappers.has(value)) { | |
| 64 path = this._paths.get(value); | |
| 65 } else if (this._paths.has(value)) { | |
| 66 path = this._paths.get(value); | |
| 67 value = this._values.get(value); | |
| 68 } else { | |
| 69 path = this._paths.get(target).concat(key); | |
| 70 this._paths.set(value, path); | |
| 71 let wrapper = new Proxy(value, this); | |
| 72 this._wrappers.set(wrapper, value); | |
| 73 this._values.set(value, wrapper); | |
| 74 value = wrapper; | |
| 75 } | |
| 76 return [value, path]; | |
| 77 }, | |
| 78 unwrap: function(target, key, value) { | |
| 79 if (!isObject(value) || !this._wrappers.has(value)) { | |
| 80 return [value, this._paths.get(target).concat(key)]; | |
| 81 } | |
| 82 return [this._wrappers.get(value), this._paths.get(target).concat(key)]; | |
| 83 }, | |
| 84 get: function(target, key) { | |
| 85 let value = target[key]; | |
| 86 let [wrapped, path] = this.wrap(target, key, value); | |
| 87 this._emitter.emit("get", path, value); | |
| 88 return wrapped; | |
| 89 }, | |
| 90 set: function(target, key, value) { | |
| 91 let [wrapped, path] = this.unwrap(target, key, value); | |
| 92 target[key] = value; | |
| 93 this._emitter.emit("set", path, value); | |
| 94 }, | |
| 95 getOwnPropertyDescriptor: function(target, key) { | |
| 96 let desc = Object.getOwnPropertyDescriptor(target, key); | |
| 97 if (desc) { | |
| 98 if ("value" in desc) { | |
| 99 let [wrapped, path] = this.wrap(target, key, desc.value); | |
| 100 desc.value = wrapped; | |
| 101 this._emitter.emit("get", path, desc.value); | |
| 102 } else { | |
| 103 if ("get" in desc) { | |
| 104 [desc.get] = this.wrap(target, "get "+key, desc.get); | |
| 105 } | |
| 106 if ("set" in desc) { | |
| 107 [desc.set] = this.wrap(target, "set "+key, desc.set); | |
| 108 } | |
| 109 } | |
| 110 } | |
| 111 return desc; | |
| 112 }, | |
| 113 defineProperty: function(target, key, desc) { | |
| 114 if ("value" in desc) { | |
| 115 let [unwrapped, path] = this.unwrap(target, key, desc.value); | |
| 116 desc.value = unwrapped; | |
| 117 Object.defineProperty(target, key, desc); | |
| 118 this._emitter.emit("set", path, desc.value); | |
| 119 } else { | |
| 120 if ("get" in desc) { | |
| 121 [desc.get] = this.unwrap(target, "get "+key, desc.get); | |
| 122 } | |
| 123 if ("set" in desc) { | |
| 124 [desc.set] = this.unwrap(target, "set "+key, desc.set); | |
| 125 } | |
| 126 Object.defineProperty(target, key, desc); | |
| 127 } | |
| 128 } | |
| 129 }; |
