XEWeb

Simple PHP caching improved

Jason — Thu, 03 Nov 2011 13:51:48 +0000

There are many tools around that will help cache your web pages to increase speed and performance (most notably Memcached) however these usually require installation on your web server, thus rendering them useless for people who use shared hosting and don’t have access to the server.

Using some simple PHP code we can quite effectively cache a webpage, useful for sites that are database driven and have a large amount of queries or high volumes of traffic.

First we need to setup the folder where the cached files are stored, making sure it has read/write permissions (CHMOD to 0777 – see your FTP client documentation on how to do this).

Next create a file called cache.php which contains the following code:

class Simple_Cache {

 // Number of seconds a page should remain cached for

 public $cache_expires = 3600;

 // Path to the cache folder

 public $cache_folder = "/home/usr/www/cache/";

 // Include query strings to make the cached page file unique

 public $include_query_strings = true;

 // The current cache file, this will get set when loaded

 private $cache_file = "";

 /**

  * Set the current cache file from the page URL

  */

 public function __construct() {

  $file = $_SERVER['REQUEST_URI'];

  if (!$this->include_query_strings && strpos($file, "?") !== false) {

   $qs = explode("?", $file);

   $file = $qs[0];

  }

  $this->cache_file = $this->cache_folder . md5($file) . ".html";

 }

 /**

  * Checks whether the page has been cached or not

  * @return boolean

  */

 public function is_cached() {

  $modified = (file_exists($this->cache_file)) ? filemtime($this->cache_file) : 0;

  return ((time() - $this->cache_expires) < $modified);

 }

 /**

  * Reads from the cache file

  * @return string the file contents

  */

 public function read_cache() {

  return file_get_contents($this->cache_file);

 }

 /**

  * Writes to the cache file

  * @param string $contents the contents

  * @return boolean

  */

 public function write_cache($contents) {

  return file_put_contents($this->cache_file, $contents);

 }

}
// Initiate the cache class

$cache = new Simple_Cache();
// Check if the page has already been cached and not expired

// If true then we output the cached file contents and finish

if ($cache->is_cached()) {

 echo $cache->read_cache();

 exit();

}
// Ok so the page needs to be cached

// Turn on output buffering

ob_start();

Now in your page you would include cache.php on the first line before you do anything else. This is because if the page is cached we don’t want it to do anything else other than output the cache to the page. If you are still including other files or connecting to databases before checking for the cache you are putting additional load on the server, making this exercise pointless.

Finally create a file called cache_footer.php which contains the following code:

// Grab the uncached page contents
$cache_contents=ob_get_contents();
ob_end_flush();
// Save it to the cache for next time

$cache->write_cache($cache_contents);

?>

You would include this file on the last line of your page, which saves the page in the cache if required.

Putting it altogether a typical page would look like this:

// Load the cache process
include("cache.php");
// Connect to database

include("config.php");

mysql_connect($db_host, $db_username, $db_password) or die(mysql_error());

mysql_select_db($db_name) or die(mysql_error());

?>

<html>

<body>

<h1>Articlesh1>

<ul>

// Some query

$query = mysql_query("SELECT * FROM articles ORDER BY id");

while ($row = mysql_fetch_array($query)) {

  echo '
.$row['id'].'">'.$row['title'].'
';

}

?>

ul>

body>

html>

// Save the cache

include("cache_footer.php");

?>

Flintstone – A key/value database store using flat files for PHP

Jason — Thu, 14 Jul 2011 11:04:53 +0000

XEWeb are proud to announce the release of Flintstone, a key/value database store using flat files for PHP.

Some of the features include:

Memory efficient
File locking
Caching
Gzip compression
Easy to use

All it requires is PHP 5 and read/write file permissions.

Take a look at example usage below:

try {

    // Load flintstone

    $db = new Flintstone(array('dir' => '/path/to/database/dir/'));

    // Set keys

    $db->load('users')->set('bob', array('email' => 'bob@site.com', 'password' => '123456'));

    $db->load('users')->set('joe', array('email' => 'joe@site.com', 'password' => 'test'));

    $db->load('settings')->set('site_offline', 1);

    $db->load('settings')->set('site_back', '3 days');

    // Retrieve keys

    $user = $db->load('users')->get('bob');

    echo 'Bob, your email is ' . $user['email'];

    $offline = $db->load('settings')->get('site_offline');

    if ($offline == 1) {

        echo 'Sorry, the website is offline
';

        echo 'We will be back in ' . $db->load('settings')->get('site_back');

    }

    // Delete a key

    $db->load('users')->delete('joe');

    // Flush database

    $db->load('users')->flush();

}

catch (Exception $e) {

    echo 'Exception: ' . $e->getMessage();

}

For more information and to download visit http://www.xeweb.net/flintstone/

Generate a random string A-Z, 0-9 in PHP

Jason — Fri, 11 Feb 2011 10:36:04 +0000

Often I find that generating a random string can be tedious, there seem to be so many ways to do this.

I wrote this simple function to do the work, and it can be easily modified.

/*

 * Create a random string

 * @author XEWeb 

 * @param $length the length of the string to create

 * @return $str the string

 */

function randomString($length = 6) {

 $str = "";

 $characters = array_merge(range('A','Z'), range('a','z'), range('0','9'));

 $max = count($characters) - 1;

 for ($i = 0; $i < $length; $i++) {

  $rand = mt_rand(0, $max);

  $str .= $characters[$rand];

 }

 return $str;

}

You can remove any of the ranges in $characters (for example if you didn’t want uppercase letters delete the range('A','Z')) or put in your own array of characters.

Bash commands to detect script injections and malware

Jason — Mon, 16 Aug 2010 15:05:23 +0000

Not so long ago this site and other domains hosted on my server were injected with malware PHP scripts that caused all sorts of damage, including amending javascript files to display ads to people who visited my sites.

These 2 bash commands saved my life and I would like to share them with the world.

The first one will find any javascript file that contains the string “eval(unescape” which is the most common way of injecting malicious code. The second is a similar method for PHP files.

find . -name "*.js" | xargs grep -l "eval(unescape"

find . -name "*.php" | xargs grep -l "eval(base64_decode"

Seek and destroy!

Thumbnail opacity hover with CSS and jQuery

Jason — Mon, 22 Mar 2010 16:32:38 +0000

A nice effect when hovering over thumbnails is to change the opacity, so that it has that fade in and out effect.

<ul class="thumbnails">

 <li><a href="#"><img src="thumb-1.jpg" alt="" /></a></li>

 <li><a href="#"><img src="thumb-2.jpg" alt="" /></a></li>

 <li><a href="#"><img src="thumb-3.jpg" alt="" /></a></li>

 <li><a href="#"><img src="thumb-4.jpg" alt="" /></a></li>

 <li><a href="#"><img src="thumb-5.jpg" alt="" /></a></li>

</ul>

Take the above example, a simple list of images. Let’s apply the basic styling for it…

ul.thumbnails { list-style: none; margin: 0; padding: 0; }

ul.thumbnails li { float: left; margin: 10px; width: 50px; height: 50px; }

ul.thumbnails li img { filter: alpha(opacity=60); /* IE only */ opacity: .60; /* All other browsers */ }

As you can see all of the thumbnails will have a default opacity of 60%. Now comes the jQuery script to add the fade effect…

$(document).ready(function(){

 $('ul.thumbnails li').hover(function(){

  $('img', this).stop().animate({opacity: 1});

 }, function() {

  $('img', this).stop().animate({opacity: 0.6});

 });

});

And that’s all there is to it!

Pure CSS coke can spin

Jason — Sat, 20 Feb 2010 10:40:51 +0000

This just goes to show what you can do with CSS these days as Román Cortés demonstrates with his awesome spinning coke can example.

I found out that by a combination of the CSS1 properties background-attachment and background-position, 2D displacement maps could be created and, by scrolling, the displacement map would be applied to different parts of the texture (a background image).

With displacement maps lots of cool effects could be done, but thinking that the complexity of the displacement map would directly affect the CSS and markup size, choosing a good example took me some time. I thought in sea waves reflections, underwater distortions, magnifying glass, a rotating Earth… but the final thing I did was just right in my desktop: a Coke can – my favourite drink.

Due the cilindrical shape of a can, the displacement map is very simple with the parallel projection I did, so the code is very little – below 5kb – and easy to understand I hope.

Even if this effect is mainly CSS1 and some bits of CSS2 – for the scrolling div, overflow: auto property -, it is not going to work in IE6, because it doesn’t support background-attachment: fixed. I’ve tested it and it works in IE8, Firefox 3.5, Chrome 3, Safari 4 and Opera 10. Also, the code validates.

Check it out at http://www.romancortes.com/blog/pure-css-coke-can/

3D carousel using jQuery

Jason — Tue, 02 Feb 2010 16:47:12 +0000

Inspired by Andrew Sellick’s Simple 3D Carousel using Mootools I needed a jQuery version of the script, source code of which is below (tested with jQuery 1.4).

Please refer to the original tutorial for instructions and a working demo.

var count =0;
var baseSpeed =0.05;
var radiusX =190;
var radiusY =40;
var centerX =300;
var centerY =190;
var speed =0.3;
var imageDivs ='';
var numberOfElements =0;
var carousel ='';
var speedTest ='';
$(document).ready(function(){

 carousel = $('#carousel');

 imageDivs = $('#carousel div');

 numberOfElements = imageDivs.length; 
 setInterval('startCarousel()', 40);

 carousel.mousemove(function(event) {

  tempX = event.clientX;

  speed = (tempX - centerX) / 2500;

 });

});
function startCarousel(){

 for(i=0; i < numberOfElements; i++){
  angle = i * ( Math.PI * 2 ) / numberOfElements;

  posX = ( Math.sin( count * ( baseSpeed * speed ) + angle )* radiusX + centerX );

  posY = ( Math.cos( count * ( baseSpeed * speed ) + angle )* radiusY + centerY );

  imageDivWidth = posY/3;

  imageDivZIndex = Math.round(imageDivWidth)+100;

  $('#carousel div').eq(i).css({'position': 'absolute', 'left': posX + 'px', 'top': posY + 'px', 'width': imageDivWidth + 'px', 'zIndex': imageDivZIndex});
  angle += speed;

 }

 count++;

}

Tweet the Tube – Live train updates on twitter

Jason — Fri, 22 Jan 2010 12:56:38 +0000

I find it frustrating getting into London these days as there are always problems on the tube that causes delays.

To take action we have launched a new service dubbed “Tweet the Tube” which provides live updates whenever a tube service changes status, pulled straight from the Transport for London website and checked every 5 minutes.

All you have to do is follow “tweetthetube” on twitter: http://twitter.com/tweetthetube

Feel free to leave comments/suggestions on this page.

Simple PHP caching

Jason — Fri, 15 Jan 2010 15:29:11 +0000

» November 2011 – improved code click here to view

There are many tools around that will help cache your website to increase speed and performance, such as eAccelerator and APC. However these usually require installation on your web server, thus rendering them useless for people who use shared hosting and don’t have access to the server.

Using some simple PHP code we can quite effectively cache a webpage, useful for sites that are database driven and have a large amount of queries or high volumes of traffic.

First we need to setup the folder where the cached files are stored, making sure it has read/write permissions (CHMOD to 0777 – see your FTP client documentation on how to do this).

Next create a file called cache.php which contains the following code:

// Number of seconds a page should remain cached for
$cache_expires=3600;
// Path to the cache folder

$cache_folder = "/home/usr/www/cache/";
// Checks whether the page has been cached or not

function is_cached($file) {

 global $cache_folder, $cache_expires;

 $cachefile = $cache_folder . $file;

 $cachefile_created = (file_exists($cachefile)) ? @filemtime($cachefile) : 0;

 return ((time() - $cache_expires) < $cachefile_created);

}
// Reads from a cached file

function read_cache($file) {

 global $cache_folder;

 $cachefile = $cache_folder . $file;

 return file_get_contents($cachefile);

}
// Writes to a cached file

function write_cache($file, $out) {

 global $cache_folder;

 $cachefile = $cache_folder . $file;

 $fp = fopen($cachefile, 'w');

 fwrite($fp, $out);

 fclose($fp);

}
// Let's begin, first work out the cached filename

$cache_file = md5($_SERVER['REQUEST_URI']) . ".html";
// Check if it has already been cached and not expired

// If true then we output the cached file contents and finish

if (is_cached($cache_file)) {

 echo read_cache($cache_file);

 exit();

}
// Ok so the page needs to be cached

// Turn on output buffering

ob_start();

Finally create a file called cache_footer.php which contains the following code:

// Grab the uncached page contents
$cache_contents=ob_get_contents();
// Save it to the cache for next time

write_cache($cache_file, $cache_contents);

?>

You would include this file on the last line of your page, which saves the page in the cache if required.

Putting it altogether a typical page would look like this:

// Load the cache process
include("cache.php");
// Connect to database

include("config.php");

mysql_connect($db_host, $db_username, $db_password) or die(mysql_error());

mysql_select_db($db_name) or die(mysql_error());

?>

<html>

<body>

<h1>Articlesh1>

<ul>

// Some query

$q = mysql_query("SELECT * FROM articles ORDER BY id");

while ($r = mysql_fetch_array($q)) {

  echo '
.$r['id'].'">'.$r['title'].'
';

}

?>

ul>

body>

html>

// Save the cache

include("cache_footer.php");

?>

GoLinks – PHP/MySQL Links Directory Script

Jason — Thu, 14 Jan 2010 13:07:47 +0000

Here at XEWeb we are cracking open a bottle of champagne as we announce the new version of GoLinks.

GoLinks is a simple yet powerful and efficient links directory script with many features including unlimited categories, link submission, search engine friendly URL’s, multiple themes and language support with completely customizable templates.

Take a look at http://www.golinks-script.com to download, order and view a demo online.