


html - My website is made with PHP+MySQL+Javascript, which is used to display dynamic data in real time. Now I want to make an alarm light on the main interface. Please give me some advice!
Reply content:
There are currently two mature solutions, Ajax polling and Web Socket, of course the latter is recommended.
As for what is said upstairsYour Web is developed by PHP server script. Unfortunately, Web Socket cannot establish communication with PHP
. From my experience, this is wrong.
I have personally practiced it (both online projects and command line Web Sockets can be implemented, which are written in PHP). There is no problem in applying Web Socket in PHP. This is basically independent of language. You can take a look at walkerman and swoole in PHP.
Or you can choose this: http://socket.io/ This can be achieved by combining it with redis.
There are currently only two technologies for obtaining factual data on the front end without refreshing the page, Ajax and Web Socket. This requires comparing the differences between the two technologies. Ajax is a completely Web-based data acquisition technology, which means that the data it can obtain is actually the result of a Web server-side script that can use URL feedback. It is obviously very suitable for you. The current use, to be precise, the design is relatively simple. However, a big drawback of Ajax technology is that it can only passively obtain information. What is passive acquisition of information? Combine it with your application scenario, the temperature is changing, when does it change? When is the data updated? Obviously, the front-end js script is unpredictable. The only thing it can do is to set a timer and obtain data every n (milli) seconds. When the data changes between this time and the last time, the chart can be updated. Such a passive approach will cause a problem. The acquisition interval is too long, making it difficult to reflect "real-time" data. The interval is too short, and a large amount of useless information is loaded (that is, the current data is the same as the previous one), thus increasing the server's processing capacity. burden. So what's a better solution? Of course there is, Web Socket based on front-end development solves this problem. It establishes a communication line with the server. No matter which party it is, it can actively send messages, and the receiving party can feedback the results in real time. So why can’t this technology be used in your current application? First of all, your Web is developed by PHP server script. Unfortunately, Web Socket cannot establish communication with PHP. What you need is to develop a server-side script that can have active requests based on the server, such as Java Socket Server. This article will not go into too much detail on how to build it.
I’m not a master, I suggest you get it asynchronously through AJAX. As mentioned in the previous section, the display method depends on your own design needs.
Read it with ajax at regular intervals, such as every one minute or ten seconds

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

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

HTML defines the web structure, CSS is responsible for style and layout, and JavaScript gives dynamic interaction. The three perform their duties in web development and jointly build a colorful website.
