How to read XML files using JS

Since the project needs to parse xml, various Baidu and then summarized the methods of parsing xml in various mainstream browsers. I can only know its usage very briefly, but there is no in-depth research.

Different browsers parse xml in different ways. According to the current mainstream browsers, they are roughly divided into three categories:

The first category, the ancestor of ie: js provides a method for creating Automation objects, new ActiveXObject("Microsoft.XMLDOM" );

Second category: firefox, opera: Use the constructor DOMParser() to instantiate the DOMParser object, parse the xml text, and return the xml Document object;

Category 3: chrome, safari: Since chrome does not support the load method, Therefore, the http protocol and XMLHttpRequest object are used.

Code:

function loadXML(){
var xmlDoc;
try{ //IE
xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
}catch(e){ //firefox,opera
xmlDoc = document.implementation.createDocument("","",null);
}
try{
xmlDoc.asyc = false; //是否异步调用
xmlDoc.load("xxx.xml"); //文件路径
}catch(e){ //chrome
var xmlhttp = new window.XMLHttpRequest();
xmlhttp.open("GET","xxx.xml",false); //创建一个新的http请求，并指定此请求的方法、URL以及验证信息
xmlDoc = xmlhttp.responseXML;
}
return xmlDoc;
}

The xmlDoc object returned, the attribute documentElement contains various values ​​​​of the xml node, you can console it and find it slowly.

ps: If you are reading local xml, chrome prohibits access to local files by default, and you need to add the startup parameter --allow-file-access-from-files.