How to make non-empty judgment of el expression in js
This time I will bring you the elexpression in jsHow to make a non-empty judgment, and the el expression in js to make a non-empty judgmentWhat are the precautionsWhat are the following? This is a practical case, let’s take a look at it.
Note, what I want to talk about here is not the use of nested el expressions in jsp, but the use in js.
Scenario:
After the page jumps, use spring mvc to pass a json object to the front-end page. After getting it in js, do the processing.
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:
Jump back to the homepage after sharing the page
The above is the detailed content of How to make non-empty judgment of el expression in js. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How to implement an online speech recognition system using WebSocket and JavaScript
Dec 17, 2023 pm 02:54 PM
How to use WebSocket and JavaScript to implement an online speech recognition system Introduction: With the continuous development of technology, speech recognition technology has become an important part of the field of artificial intelligence. The online speech recognition system based on WebSocket and JavaScript has the characteristics of low latency, real-time and cross-platform, and has become a widely used solution. This article will introduce how to use WebSocket and JavaScript to implement an online speech recognition system.
WebSocket and JavaScript: key technologies for implementing real-time monitoring systems
Dec 17, 2023 pm 05:30 PM
WebSocket and JavaScript: Key technologies for realizing real-time monitoring systems Introduction: With the rapid development of Internet technology, real-time monitoring systems have been widely used in various fields. One of the key technologies to achieve real-time monitoring is the combination of WebSocket and JavaScript. This article will introduce the application of WebSocket and JavaScript in real-time monitoring systems, give code examples, and explain their implementation principles in detail. 1. WebSocket technology
How to use JavaScript and WebSocket to implement a real-time online ordering system
Dec 17, 2023 pm 12:09 PM
Introduction to how to use JavaScript and WebSocket to implement a real-time online ordering system: With the popularity of the Internet and the advancement of technology, more and more restaurants have begun to provide online ordering services. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects dishes and places an order
JavaScript and WebSocket: Building an efficient real-time weather forecasting system
Dec 17, 2023 pm 05:13 PM
JavaScript and WebSocket: Building an efficient real-time weather forecast system Introduction: Today, the accuracy of weather forecasts is of great significance to daily life and decision-making. As technology develops, we can provide more accurate and reliable weather forecasts by obtaining weather data in real time. In this article, we will learn how to use JavaScript and WebSocket technology to build an efficient real-time weather forecast system. This article will demonstrate the implementation process through specific code examples. We
Simple JavaScript Tutorial: How to Get HTTP Status Code
Jan 05, 2024 pm 06:08 PM
JavaScript tutorial: How to get HTTP status code, specific code examples are required. Preface: In web development, data interaction with the server is often involved. When communicating with the server, we often need to obtain the returned HTTP status code to determine whether the operation is successful, and perform corresponding processing based on different status codes. This article will teach you how to use JavaScript to obtain HTTP status codes and provide some practical code examples. Using XMLHttpRequest
How to determine whether a date is the previous day in Go language?
Mar 24, 2024 am 10:09 AM
Question: How to determine whether the date is the previous day in Go language? In daily development, we often encounter situations where we need to determine whether the date is the previous day. In the Go language, we can implement this function through time calculation. The following will be combined with specific code examples to demonstrate how to determine whether the date is the previous day in Go language. First, we need to import the time package in the Go language. The code is as follows: import("time") Then, we define a function IsYest
jQuery usage practice: several ways to determine whether a variable is empty
Feb 27, 2024 pm 04:12 PM
jQuery is a JavaScript library widely used in web development. It provides many simple and convenient methods to operate web page elements and handle events. In actual development, we often encounter situations where we need to determine whether a variable is empty. This article will introduce several common methods of using jQuery to determine whether a variable is empty, and attach specific code examples. Method 1: Use the if statement to determine varstr="";if(str){co
How to get HTTP status code in JavaScript the easy way
Jan 05, 2024 pm 01:37 PM
Introduction to the method of obtaining HTTP status code in JavaScript: In front-end development, we often need to deal with the interaction with the back-end interface, and HTTP status code is a very important part of it. Understanding and obtaining HTTP status codes helps us better handle the data returned by the interface. This article will introduce how to use JavaScript to obtain HTTP status codes and provide specific code examples. 1. What is HTTP status code? HTTP status code means that when the browser initiates a request to the server, the service
