Talking about PHP generating static page analysis template + cache + writing files_PHP tutorial

1. Introduction
In terms of speed, static pages are much faster than dynamic pages such as PHP. This is undoubtedly true. However, due to the poor flexibility of static pages, if you do not use a database or other devices to save relevant information, In other words, the overall management is more cumbersome, such as modification and editing, such as reading permission restrictions, etc. However, for some files that we often use frequently, such as the news release system we develop, we do not want many users to read the database before displaying it. As a result, on the one hand, this consumes the resources of the server, and on the other hand, it takes up a lot of valuable response time of the browser. Therefore, with the "static page" approach, many websites currently use this technology, usually by Management background control, or generating html for direct display, or using xhtml to control display with css, or generating xml for display with xslt. These techniques are not difficult. Here I will briefly talk about the method of generating html.
2. Preparation Knowledge
Template technology:
[PHP] An in-depth introduction to the template engine Smarty--2005-12-31
[PHP] Talking about configuration and using Smarty technology--2006-01-04
Caching technology:
Some information, such as information that is often constant but can still change, is placed in the cache to speed up the display. This is very valuable. The so-called cache is generally understood to be some shared information stored on the server side. It It is the same as the server. When saving the cache, we can specify the judgment of the next update time. For example, if it needs to be updated every 5 minutes, we can record the last update time and compare it with the current time. If it is greater than 5 minutes, read Get the database and update it, otherwise read the cached data directly. Of course, the cache needs to be activated by the client user, which only needs to be done once.
ob_start() function: Open the output buffer.
Function format void ob_start(void )
Note: When the buffer is activated, all non-file header information from the PHP program will not be sent, but will be saved in the internal buffer. In order to output the contents of the buffer, you can use ob_end_flush() or flush() to output the contents of the buffer.
Flush: Flush the contents of the buffer and output.
Function format: flush()
Description: This function is frequently used and is very efficient.
ob_get_contents: Returns the contents of the internal buffer.
Function format: string ob_get_contents(void)
Description: This function will return the contents of the current buffer. If the output buffer is not activated, it will return FALSE.
ob_get_length: Returns the length of the internal buffer.
Function format: int ob_get_length(void)
Description: This function will return the length in the current buffer; like ob_get_contents, if the output buffer is not activated, it returns FALSE.
ob_end_clean: Delete the internal buffer area, and close the internal buffer
Function format: void ob_end_clean(void)
Description: This function will not output the content of the internal buffer but delete it
ob_end_flush: Send the internal buffer Content to the browser, and close the output buffer
Function format: void ob_end_flush(void)
Description: This function sends the content of the output buffer (if any)
ob_implicit_flush: Turn on or turn off absolute refresh
Function format: void ob_implicit_flush ([int flag])
Description: The default is to close the buffer. After turning on absolute output, each script output is sent directly to the browser, and there is no need to call flush()
File writing:
int fwrite (resource handle, string string [, int length])
fwrite() writes the contents of string to the file pointer handle. If length is specified, writing will stop when length bytes have been written or when the string has been written, whichever occurs first.
fwrite() returns the number of characters written, or FALSE if an error occurs.
Related reference official website: File reference
3. Solution
Idea: turn on ob_start buffer, get ob_get_contents when the data has been transferred out, then generate a static page, ob_end_clean clear the buffer.ok, that’s it , let’s look at an example (combination of php+mysql):
Create database: