How to Implement DOM Data Binding in JavaScript

Please treat this question as strictly educational. I'm still interested in hearing new answers and ideas to implement this tl;dr How would I implement bi-directional data-binding with JavaScript? Data Binding to the DOM By data binding to the DOM I mean for example, having a JavaScript object a with a property b . Then having an <input> DOM element (for example), when the DOM

如何在JavaScript中实现DOM数据绑定

请把这个问题视为严格的教育。 我仍然有兴趣听到新的答案和想法来实现这一点 TL;博士 我将如何实现与JavaScript的双向数据绑定? 数据绑定到DOM 通过数据绑定到DOM我的意思是,例如,具有一个JavaScript对象a与属性b 。 然后有一个<input> DOM元素(例如),当DOM元素发生变化时, a变化,反之亦然(即我的意思是双向数据绑定)。 这里是AngularJS的一个图表,它看起来像这样: 所以基本上我有JavaScript类

How to handle initializing and rendering subviews in Backbone.js?

I have three different ways to initialize and render a view and its subviews, and each one of them has different problems. I'm curious to know if there is a better way that solves all of the problems: Scenario One: Initialize the children in the parent's initialize function. This way, not everything gets stuck in render so that there is less blocking on rendering. initialize : func

如何处理Backbone.js中的初始化和渲染子视图?

我有三种不同的方式来初始化和渲染视图及其子视图,并且每个视图都有不同的问题。 我很想知道是否有更好的解决所有问题的方法: 情景一: 在父项的初始化函数中初始化子项。 这样,并非所有东西都会在渲染过程中卡住,从而减少渲染阻塞。 initialize : function () { //parent init stuff this.child = new Child(); }, render : function () { this.$el.html(this.template()); this.child.render()

I know its bad to store data in the DOM, but why?

I've heard over and over again that it is bad practice to "use the DOM as a database." While I mostly agree with that sentiment, this question is more about the less black and white cases. Keeping in mind the latest revisions to jQuery's .data() methods and the HTML5 data-attribute spec, is it really so bad to stick some data in the DOM for the sake of convenience? For exam

我知道它不好在DOM中存储数据,但为什么?

我一遍又一遍地听到“将DOM用作数据库是不好的做法”。 虽然我大多同意这种观点,但这个问题更多的是关于黑白案例的少。 记住jQuery的.data()方法和HTML5数据属性规范的最新版本,为了方便起见,将一些数据粘贴到DOM中确实很糟糕。 例如,我最近通过执行如下操作在一个充满输入的表上实现了“实时”计算功能: <table> <tr> <td><input type="text"></td> </tr> <tr>

Remove all child elements of a DOM node in JavaScript

How would I go about removing all of the child elements of a DOM node in JavaScript? Say I have the following (ugly) HTML: <p id="foo"> <span>hello</span> <div>world</div> </p> And I grab the node I want like so: var myNode = document.getElementById("foo"); How could I remove the children of foo so that just <p id="foo"></p>

在JavaScript中删除DOM节点的所有子元素

我将如何去除JavaScript中DOM节点的所有子元素? 假设我有以下(难看的)HTML: <p id="foo"> <span>hello</span> <div>world</div> </p> 我抓住我想要的节点: var myNode = document.getElementById("foo"); 我怎样才能删除foo的孩子,这样只剩下<p id="foo"></p>了? 我可以这样做吗? myNode.childNodes = new Array(); 或者我应该使用removeE

jQuery counting elements by class; what is the best way to implement this?

What I'm trying to do is to count all of the elements in the current page with the same class and then I'm going to use it to be added onto a name for an input form. Basically I'm allowing users to click on a <span> and then by doing so add another one for more of the same type of items. But I can't think of a way to count all of these simply with jQuery/JavaScript. I wa

jQuery按类来计算元素; 什么是实施这个最好的方法?

我想要做的是用相同的类来计算当前页面中的所有元素,然后我将使用它添加到输入表单的名称上。 基本上,我允许用户点击<span> ,然后再为另外一个相同类型的项目添加另一个。 但我想不出用jQuery / JavaScript简单计算所有这些数据的方法。 我打算将这个项目命名为name="whatever(total+1)" ,如果任何人有一个简单的方法来做到这一点,我会非常感激,因为JavaScript不完全是我的母语。 应该是这样的: //

Using same argument name as its default parameter in ES6

This ES6 code: const log = () => console.log('hi'); const parent = (log = log) => log(); parent(); Transpiled to: var log = function log() { return console.log('hi'); }; var parent = function parent() { var log = arguments.length <= 0 || arguments[0] === undefined ? log : arguments[0]; return log(); }; parent(); Gives error: return log(); ^ TypeError: log

在ES6中使用相同的参数名称作为其默认参数

这个ES6代码: const log = () => console.log('hi'); const parent = (log = log) => log(); parent(); 运输到: var log = function log() { return console.log('hi'); }; var parent = function parent() { var log = arguments.length <= 0 || arguments[0] === undefined ? log : arguments[0]; return log(); }; parent(); 给出错误: return log(); ^ TypeError: log is not a

How to determine a user's operating system through node?

有没有办法确定用户浏览的操作系统,以及它是64位还是32位 Use nodejs built in module os for getting architecture information OS module Docs var os = require("os"); console.log(os.arch()); //ia32 you can use process object porcess.arch //'ia32'

如何通过节点确定用户的操作系统?

有没有办法确定用户浏览的操作系统,以及它是64位还是32位 使用模块os构建的nodejs来获取体系结构信息 OS模块文档 var os = require("os"); console.log(os.arch()); //ia32 你可以使用过程对象 porcess.arch //'ia32'

ReactNative ListView setting initial scroll position after data loaded

I have an events section which has section headings containing the date. I need to be able to jump to specific dates, as well as have the initial scroll position set to the first date in the future. In order to jump to specific dates I have tried storing their y positions in state. renderSectionHeader= (sectionData, sectionID) => ( <View onLayout={(event) => {

ReactNative ListView设置数据加载后的初始滚动位置

我有一个活动部分,其中有部分标题包含日期。 我需要能够跳转到特定日期,并且将初始滚动位置设置为将来的第一个日期。 为了跳到特定的日期,我尝试将它们的y位置存储在状态中。 renderSectionHeader= (sectionData, sectionID) => ( <View onLayout={(event) => { const { y } = event.nativeEvent.layout; const sectionPosition = { [sectionID]: y }; const sectio

Are there constants in JavaScript?

Is there a way to use constants in JavaScript? If not, what's the common practice for specifying variables that are used as constants? Since ES2015, JavaScript has a notion of const : const MY_CONSTANT = "some-value"; This will work in pretty much all browsers except IE 8, 9 and 10. Some may also need strict mode enabled. You can use var with conventions like ALL_CAPS to show that cer

JavaScript中有常量吗?

有没有办法在JavaScript中使用常量? 如果没有,指定用作常量的变量的常用做法是什么? 自ES2015以来,JavaScript有一个const的概念: const MY_CONSTANT = "some-value"; 这将适用于除IE 8,9和10以外的几乎所有浏览器。有些可能还需要启用严格模式。 如果您需要支持旧浏览器或正在使用旧代码,则可以使用var与ALL_CAPS等约定来显示某些值不应该被修改: var MY_CONSTANT = "some-value"; 你是否试图保护变量免受修改

What is simplified in ECMAScript 5 date format compared to ISO 8601

ECMAScript defines a string interchange format for date-times based upon a simplification of the ISO 8601 Extended Format. The format is as follows: YYYY-MM-DDTHH:mm:ss.sssZ — https://www.ecma-international.org/ecma-262/5.1/#sec-15.9.1.15 So what exactly is the difference between the two formats? What do I have to be careful about? I noticed that ISO 8601 states that the T can be substitut

与ISO 8601相比,ECMAScript 5日期格式简化了什么

ECMAScript根据ISO 8601扩展格式的简化定义了日期时间的字符串交换格式。 格式如下:YYYY-MM-DDTHH:mm:ss.sssZ - https://www.ecma-international.org/ecma-262/5.1/#sec-15.9.1.15 那么这两种格式之间究竟有什么区别呢? 我必须注意些什么? 我注意到ISO 8601指出T可以用空格代替。 还有什么是“简化”? 非常具体:这个问题是关于标准。 浏览器行为很有趣,但不是这个问题的主要焦点。 ISO 8601为日期和时间定