defineproperty

Extend setter default object

由 巧了我就是萌 提交于 2019-12-24 05:26:09
问题 Like you all know a button is a button... click, up, down, do this, do that. So I wrote some default button behavior "class/object". external default button.js: function Button(parent) { var self = this; this.enabled = true; this.visible = true; ... this.initialized = false; f_createButton(parent, self); this.initialized = true; ... } Button.prototype = { get initialized () { return this._initialized; }, set initialized(bool){ this._initialized = bool if(this.initialized === true) { ... do

How to customize properties in TypeScript

由 拈花ヽ惹草 提交于 2019-12-20 09:56:34
问题 How do I get TypeScript to emit property definitions such as: Object.defineProperties(this, { view: { value: view, enumerable: false, writable: false, configurable: false }, }); 回答1: I was looking for exactly the same thing when I stumbled upon TypeScript Handbook: Decorators. In "Method Decorators" paragraph they define @enumerable decorator factory, which looks like this (I'm simply copy-pasting from there): function enumerable(value: boolean) { return function (target: any, propertyKey:

Object.defineProperty for all browsers?

由 不想你离开。 提交于 2019-12-20 09:53:46
问题 Asking about Object.defineProperty as demonstrated below: function testComponent(){ var testProperty; Object.defineProperty(this, "testProperty", { get : function() { return testProperty; }, set : function(val) { testProperty = val; } }); } Where it would be used like so: testObject = new testComponent(); testObject.testProperty = "testValue"; Based on what I've seen so far, it looks like there is no cross browser solution, as I've tried using es5-shim with no luck, but I would like to

Using Object.defineProperty on a defined property

由 ↘锁芯ラ 提交于 2019-12-13 02:35:32
问题 Consider a pattern like this, where we want to define a nice getter/setter interface for a property to hide some internal validation: var validThings = { 'pretty name a': 3293293, 'pretty name b': 8275850, 'pretty name c': 2983855 }; function Constructor() { var internalThing = { name: 'pretty name a', id: '3293293' }; Object.defineProperty(this, 'thing', { get: function() { return internalThing.name; }, set: function(val) { var id = validThings[val]; if (id) internalThing = { name: val, id:

Object.defineProperty vs vanilla property

由 吃可爱长大的小学妹 提交于 2019-12-12 15:41:00
问题 Considering the basic scenario of usage, do foo.bar = 'baz'; and Object.defineProperty(foo, 'bar', { value: 'baz', configurable: true, enumerable: true, writable: true }); behave exactly the same in supported browsers? Can we fall back to vanilla in pre-ES6 applications just because of favourable syntax or mix both of them without any side effects? 回答1: Yes, they behave the same when there is no bar property in foo (not even an inherited one), so a new one is created, or there is a bar

Object create define property setter

由 ◇◆丶佛笑我妖孽 提交于 2019-12-12 02:51:49
问题 I need to make it so that every time a specific property on my object is changed - it will call a special method on the same object. Example: MyObject.prototype = Object.create({ specialMethod: function() { /* ... */ } }, { someValue: { set: function(value) { /* HOW DO I ASSIGN THE VALUE TO MyObject HERE?*/ /* I can't do: this.someValue=value, that would create endless recursion */ this.specialMethod(); } } }); How do I assign the value to MyObject within the property setter? 回答1: There is no

How to make a property/method invokable or not?

由 岁酱吖の 提交于 2019-12-11 03:42:10
问题 I want to achieve this functionality: I have an object var obj = {}; I have three properties on that obj, obj.zero & obj.one & obj.binaryString obj.zero & obj.one are methods while obj.binaryString is a string When I chain the properties, I want them to add their respective digit to the binaryString . So for example: obj.one.zero.zero.one => makes obj.binaryString = 1001 obj.one.zero.one.one.zero => makes obj.binaryString = 10110 I have achieved the above functionality with this: function

Is it valid to use Object.defineProperties with symbols?

由 偶尔善良 提交于 2019-12-10 18:38:54
问题 Let's take the following code: var obj = {}; var x = Symbol(); Object.defineProperties(obj, { [x]: { value: true, writable: true }, "property2": { value: "Hello", writable: false } // etc. etc. }); console.log(obj[x]) Is this valid? With the native Object.defineproperties code we get in the console.log true. With the polyfill of zone.js which is of the form of : Object.defineProperties = function (obj, props) { Object.keys(props).forEach(function (prop) { Object.defineProperty(obj, prop,

Clarication needed for implementing properties with the revealing module pattern using Html5 getters and setters

由 流过昼夜 提交于 2019-12-07 15:45:59
问题 I've searched a lot for how to do properties in Javascript. Most all of the revealing module pattern I've seen has exclusively exposed functions, and from experience I know if I expose an object, I'm only really getting a copy of the value right there and then, thus simply I could have a function getMyThing() and setMyThing and expose that. However I'm wanting to expose real properties I've seen the oldschool defineGetter which I'm avoiding and the newer Object.defineProperty( which I had

Clarication needed for implementing properties with the revealing module pattern using Html5 getters and setters

由 纵饮孤独 提交于 2019-12-05 20:49:10
I've searched a lot for how to do properties in Javascript. Most all of the revealing module pattern I've seen has exclusively exposed functions, and from experience I know if I expose an object, I'm only really getting a copy of the value right there and then, thus simply I could have a function getMyThing() and setMyThing and expose that. However I'm wanting to expose real properties I've seen the oldschool defineGetter which I'm avoiding and the newer Object.defineProperty( which I had some real troubles with. (I could easily use it against an artitary object but not THIS inside my "module"
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