A brief discussion on the caching mechanism of Ajax
This article mainly introduces us to a few simple rules and precautions of the AJAX caching mechanism. It is very good and is recommended to everyone here.
The caching mechanism of Ajax is the same as the caching mechanism of the browser when processing resources.
Three simple rules:
As long as it is a GET request with the same URL, the browser will use the cache (of course it also depends on the server's Cache-Control/Expires/Last-Modified/ETag header settings) ).
As long as it is a POST request, the browser will not cache it.
Https requests will not be cached by the browser (this is the case in most cases, but there are exceptions, and it is said that FF browser is an exception).
Supplement:
Inserting a random query string into the URL can make the browser think that this is a new request and thus not use the cache.
Set the Http header in the Ajax request: If-Modified-Since:0 to tell the server to ask for new content.
Supplementary Note:
Under normal circumstances, if the user manually triggers the browser refresh (windows:F5 MacOS:command R), the browser will ignore the setting of the Cache-Control/Expires header of the resource. And go connect to the server. This is true whether it is a page refresh or an Ajax refresh.
The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.
Related articles:
Ajax core XMLHttpRequest summary
Solving the problem of ajax cross-domain request data cookie loss
Use ajax to change page content and address bar URL without refreshing
##
The above is the detailed content of A brief discussion on the caching mechanism of Ajax. 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

AI Hentai Generator
Generate AI Hentai for free.

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

DNS (DomainNameSystem) is a system used on the Internet to convert domain names into corresponding IP addresses. In Linux systems, DNS caching is a mechanism that stores the mapping relationship between domain names and IP addresses locally, which can increase the speed of domain name resolution and reduce the burden on the DNS server. DNS caching allows the system to quickly retrieve the IP address when subsequently accessing the same domain name without having to issue a query request to the DNS server each time, thereby improving network performance and efficiency. This article will discuss with you how to view and refresh the DNS cache on Linux, as well as related details and sample code. Importance of DNS Caching In Linux systems, DNS caching plays a key role. its existence

Using Ajax to obtain variables from PHP methods is a common scenario in web development. Through Ajax, the page can be dynamically obtained without refreshing the data. In this article, we will introduce how to use Ajax to get variables from PHP methods, and provide specific code examples. First, we need to write a PHP file to handle the Ajax request and return the required variables. Here is sample code for a simple PHP file getData.php:

Optimizing Cache Size and Cleanup Strategies It is critical to allocate appropriate cache size to APCu. A cache that is too small cannot cache data effectively, while a cache that is too large wastes memory. Generally speaking, setting the cache size to 1/4 to 1/2 of the available memory is a reasonable range. Additionally, having an effective cleanup strategy ensures that stale or invalid data is not kept in the cache. You can use APCu's automatic cleaning feature or implement a custom cleaning mechanism. Sample code: //Set the cache size to 256MB apcu_add("cache_size",268435456); //Clear the cache every 60 minutes apcu_add("cache_ttl",60*60); Enable compression

In PHP development, the caching mechanism improves performance by temporarily storing frequently accessed data in memory or disk, thereby reducing the number of database accesses. Cache types mainly include memory, file and database cache. Caching can be implemented in PHP using built-in functions or third-party libraries, such as cache_get() and Memcache. Common practical applications include caching database query results to optimize query performance and caching page output to speed up rendering. The caching mechanism effectively improves website response speed, enhances user experience and reduces server load.

PHPAPCu (replacement of php cache) is an opcode cache and data cache module that accelerates PHP applications. Understanding its advanced features is crucial to utilizing its full potential. 1. Batch operation: APCu provides a batch operation method that can process a large number of key-value pairs at the same time. This is useful for large-scale cache clearing or updates. //Get cache keys in batches $values=apcu_fetch(["key1","key2","key3"]); //Clear cache keys in batches apcu_delete(["key1","key2","key3"]);2 .Set cache expiration time: APCu allows you to set an expiration time for cache items so that they automatically expire after a specified time.

There is a close interaction between the CPU (central processing unit), memory (random access memory), and cache, which together form a critical component of a computer system. The coordination between them ensures the normal operation and efficient performance of the computer. As the brain of the computer, the CPU is responsible for executing various instructions and data processing; the memory is used to temporarily store data and programs, providing fast read and write access speeds; and the cache plays a buffering role, speeding up data access speed and improving The computer's CPU is the core component of the computer and is responsible for executing various instructions, arithmetic operations, and logical operations. It is called the "brain" of the computer and plays an important role in processing data and performing tasks. Memory is an important storage device in a computer.

Advantages of Using APCu APCu provides the following key benefits: Improved website speed: By caching data and pages, APCu reduces querying to the database and page generation time, thereby increasing overall website speed. Ease server load: Caching data and pages reduces demand on server resources, easing server load and preventing crashes during peak periods. Improved user experience: Faster website speed leads to a better user experience, increased conversion rates and lower bounce rates. Easy to integrate: APCu can be easily integrated into WordPress, Drupal, and other PHP applications without major code modifications. How APCu works APCu uses PHP memory to store data and pages. It stores the following data in cache

Ajax (Asynchronous JavaScript and XML) allows adding dynamic content without reloading the page. Using PHP and Ajax, you can dynamically load a product list: HTML creates a page with a container element, and the Ajax request adds the data to that element after loading it. JavaScript uses Ajax to send a request to the server through XMLHttpRequest to obtain product data in JSON format from the server. PHP uses MySQL to query product data from the database and encode it into JSON format. JavaScript parses the JSON data and displays it in the page container. Clicking the button triggers an Ajax request to load the product list.
