Detailed explanation of how JavaScript dynamically creates DOM instances using strings-JS Tutorial-php.cn

Detailed explanation of how JavaScript dynamically creates DOM instances using strings

伊谢尔伦

Release： 2017-07-18 16:16:55

Original

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To dynamically create a standard dom object in JavaScript, generally use:

var obj = document.createElement(&#39;p&#39;);

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Then set some properties for obj.
However, in actual use, some people may think that it would be great if a standard dom object could be created like this
Pseudo code: var obj=strToDom('

Hello World!

');
The purpose of today is to teach you how to implement such a method to directly convert a string into a standard DOM object

start:
In fact, it is very simple to implement such a conversion. Here we mainly use an attribute innerHTML.
innerHTML, I believe everyone has used it, especially to dynamically convert an element It is used when inserting content. Here I will introduce innerHTML for the convenience of those who are not familiar with it.
InnerHTML is not a w3c standard, it was invented and created by IE. However, due to the convenience of this attribute and the status of Weibo at the time, other non-IE browsers also built-in innerHTML and provided support.
Although innerHTML is not a w3c standard, it is a de facto standard. This de facto standard is very important. That is, all mainstream browsers currently support innerHTML, so it is naturally compatible with multiple browsers.

function parseDom(arg) { 
　　 var objE = document.createElement("p"); 
　　 objE.innerHTML = arg; 
　　 return objE.childNodes; 
};

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The conversion is achieved in just a few lines of code. We first create a p using the standard method, and then use innerHTML to insert an element. In fact, we use the browser's own kernel algorithm to A conversion implemented. Return it using childNodes.
In this way, we have completed the conversion of a string to standard DOM. Cleverly using the browser's own algorithm, we can complete a large number of complex conversions with a simple and small amount of code. We do not need to parse the string, but leave it to The browser does it itself, which is accurate and error-free.
Usage:

var obj=parseDom(&#39;<p id="p_1" class="p1">Hello World!</p>&#39;); 
var obj=parseDom(&#39;<p id="p_1" class="p1">Hello World!</p><span>多个也没关系</span>&#39;);

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Note:
childNodes returns an array-like list. So if it is an element, to use this dom you need to use obj[0] like this. If it is multiple DOM conversions at the same level, you can use obj[0], obj[1]...

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