How to use el expression and non-empty judgment in js

This time I will show you how to use el expressions and non-empty judgments in js. What are the precautions for using el expressions and non-empty judgments in js. The following is a practical case, let's take a look.

After the page jumps, use spring mvc to pass a jsonobject to the front-end page, which needs to be obtained in js and processed.

Returned json object:

{"nodes":[{"contactmobile":"15922208502","orderno":"XNH31918062989476864"},{"id":"12198","group":"11","content":"把考虑考虑","modelname":"Company"}],"links":[{"target":"12198","id":"15016","relationType":"公司","source":"12194"}]}

var graph; 
var flag = "${empty jsonData}"; 
if(flag!="true"){ 
  graph = eval('(' + '${jsonData}' + ')'); 
};

There is a note here:

When using el expressions in js, be sure to use quotation marks. If the returned json contains double quotes, then use single quotes to surround the el expression, otherwise, use double quotes.

In addition, pay attention to the writing method of using evalfunction to convert the json string into an object.

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

Recommended reading:

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How to create an E-mail address format in JS verify

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