Detailed explanation of Meta http-equiv attributes (transfer), metahttp-equiv_PHP tutorial

Meta http-equiv attribute detailed explanation (translated), metahttp-equiv

http-equiv, as the name suggests, is equivalent to the file header function of http. It can return some useful information to the browser. information to help display web page content correctly and accurately. The corresponding attribute value is content. The content in content is actually the variable value of each parameter.

1. Expires
Description: Can be used to set the expiration time of the web page. Once a web page expires, it must be retransmitted to the server.
Usage:

1. ＜meta http-equiv="expires" content="Wed, 20 Jun 2007 22:33:00 GMT"＞

Note: GMT time format must be used.

2. Pragma (cache mode)
Description: It is used to set up to prohibit the browser from accessing page content from the cache of the local machine. Once you leave the webpage after setting, Cannot be retrieved from Cache
Usage:

1. ＜meta http-equiv="Pragma" content="no-cache"＞

Note: With this setting, visitors will not be able to browse offline.

3. Refresh
Description: Automatically refresh and point to a new page.
Usage:

1. ＜meta http-equiv="Refresh" content="2；URL=http://www.net.cn/"＞

Note: The 2 refers to automatically refreshing to the URL after staying for 2 seconds.

4. Set-Cookie (cookie setting)
Note: If the web page expires, the saved cookies will be deleted.
Usage:

1. ＜meta http-equiv="Set-Cookie" content="cookievalue=xxx;expires=Wednesday, 20-Jun-2007 22:33:00 GMT; path ="＞

Note: GMT time format must be used.

5. Window-target (display window setting)
Description: Force the page to be displayed as an independent page in the current window.
Usage:

1. ＜meta http-equiv="Window-target" content="_top"＞

Note: Used to prevent others from calling your own page in the frame.

6. content-Type (display character set setting)
Description: Set the character set used by the page.
Usage:

1. ＜meta http-equiv="content-Type" content="text/html; charset=gb2312"＞

7. Pics-label (webpage rating)
Usage:

1. meta http-equiv="Pics-label" contect="">

Note: There is a content setting in IE's internet options that can prevent browsing of some restricted websites, and the restriction level of the website is set through the meta attribute.

8. Page_Enter, Page_Exit
Set special effects when entering the page

1. meta http-equiv="Page-Enter" contect="revealTrans(duration=1.0,transtion= 12)" > 

Set special effects when leaving the page

1. meta http-equiv="Page-Exit" contect="revealTrans(duration=1.0,transtion= 12)" > 

The value of Duration is the time for dynamic transition of the web page, in seconds.
Transition is the transition method, its value is 0 to 23, corresponding to 24 transition methods. As shown in the table below:
0 Box-shaped contraction 1 Box-shaped radiation
2 Circular shrinkage 3 Circular radiation
4 From bottom to top 5 From top to bottom
6 From left to right 7 From right to Left
8 Vertical blinds 9 Horizontal blinds
10 Horizontal grid blinds 11 Vertical grid blinds
12 Dissolve at will 13 Expand from the left and right ends to the middle
14 Expand from the middle to the left and right ends 15 From Expand from the upper and lower ends to the middle
16 Expand from the middle to the upper and lower ends 17 Expand from the upper right corner to the lower left corner
18 Expand from the lower right corner to the upper left corner 19 Expand from the upper left corner to the lower right corner
20 From the lower left Expand the corner to the upper right corner 21 Horizontal linear expansion
22 Vertical linear expansion 23 Randomly generate a transition method

9. Clear cache (re-download when visiting this website again!)

1. meta http-equiv="cache-control" content="no-cache">

10. Set the expiration time of the web page

1. meta http-equiv="expires" content="0">

11. Keywords, used by search engines

1. meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

12. Page description

1. meta http-equiv="description" content="This is my page">