PHP Cache specific parts of a page

Question

I have sections on a page that require a fair amount of resources that I would like to cache, here is an example of the page.

[=== Some Static HTML ===]
[=== PHP Script 1 ===]
[=== Some Static HTML ===]
[=== PHP Script 2 ===]

I would like to put "PHP Script 1" into a cache file eg script1.html and include it rather than processing the whole script, and the same for Script 2.

The problem I have is I can cache the whole page easily and it works but I would like to just cache specific parts (as above) because some things like user session data needs to be live.

I have this class that is meant to be able to stop and start the buffer so I can pull out specific parts without breaking the rest of the page however it doesn't do what I want. http://pastebin.com/Ua6DDExw

I would like to be able to go like this below, while it would store the section in a file with a simple php inlcude rather hitting the database.

HTML Content

<?php
$cache->start_buffer("cache_name");
// PHP Script
$cache->end_buffer("cache_name");
?>

HTML Content

<?php
$cache->start_buffer("cache_name");
// PHP Script
$cache->end_buffer("cache_name");
?>

I don't have access to memcache or anything else like that because this will be going on shared hosting.

Any help would be great, Thanks

Answer 1

look into using ob_start() and ob_flush() It does what you are looking to do. You'll need to manually write it to a file. There are cache.php classes out in the wild as well.

http://php.net/manual/en/function.ob-start.php

<?php  

  $cache_time = 3600; // Time in seconds to keep a page cached  
  $cache_folder = '/cache'; // Folder to store cached files (no trailing slash)  

  // Think outside the box the original said to use the URI instead use something else.
  $cache_filename = $cache_folder.md5(",MyUniqueStringForMyCode"); // Location to lookup or store cached file  

  //Check to see if this file has already been cached  
  // If it has get and store the file creation time  
  $cache_created  = (file_exists($cache_file_name)) ? filemtime($this->filename) : 0;

  if ((time() - $cache_created) < $cache_time) {  
    $storedData = readCacheFile($cache_filename);
  }
  else
  {

    // Alternatively you can ignore the ob_start/get_contents/end_flush code 
    // and just call a function and store it directly to the variable.
    // Start saving stuff
    ob_start();  

    /** do your work here echoing data to the screen */

    $storedData = ob_get_contents();
    ob_end_flush();

    // create the cachefile for the data.
    createCacheFile($cache_filename);
  }


  // Do stuff with $storedData.