How to use php to configure the browser not to generate cache

When developing web applications, we usually encounter browser cache issues. During the development and testing process, due to the existence of browser cache, our modifications to the code may not take effect immediately, which causes a lot of inconvenience to development and testing.

Below, we will introduce how to use php to configure the browser not to generate cache.

1. Use php's header function

php provides a header function, which can send a raw HTTP header information to the browser. We can use it to set up browsing server cache. By setting the Expires and Cache-Control response headers in the header function, we can instruct the browser not to cache the page. For example:

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Cache-Control: no-cache");

This code sets the Expires in the response header to an expiration date, telling the browser not to cache the page. Similarly, Cache-Control: no-cache means not to cache the page.

2. Set the Pragma response header

Another way to set the browser cache is by setting the Pragma response header. The Pragma header instructs the page not to be cached, and is a legacy header from the HTTP/1.0 protocol. For example:

header("Pragma: no-cache");

3. Set HTML tags

In addition to setting response headers, we can also use meta tags in HTML pages, so that the browser can be set when the page loads cache. For example:

<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate">
<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="Expires" content="0">

This meta tag tells the browser not to cache the page. The value of Content is no-cache, no-store, and must-revalidate means not to cache the page. The value of Pragma is no-cache means not to cache the page. , a value of Expires of 0 indicates that the page has expired.

4. Static resources append random strings

For static resources (such as CSS, JS, images, etc.), we can add random strings to their links, so The browser will get new content every time it requests these resources. For example:

<link rel="stylesheet" href="style.css?v=<?=rand(1, 10000)?>" />

The rand function here generates a random number and appends it to the URL parameter, so that a new URL will be generated every time this resource is requested, thus avoiding browser caching. Similarly, we can also use similar methods in JS, images and other resources.

Summary

Configuring the browser not to generate cache is very important for web development and testing, because it can avoid problems such as untimely code updates caused by browser cache. PHP provides the header function to set response headers. You can also use meta tags in HTML to set browser cache. You can also append random strings to static resources to avoid caching. I hope this article will be helpful to everyone when learning and using php to configure browser cache.

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