How To use:
First, include the class and initiate it:

Optionally, you can use new Validation(false) to not parse all input data through the xss filter. This is not recommended.

Available functions are:

• xss($string)
• email($string)
• phone($string)
• url($string)
• db_prep($string)

All of the above functions return a boolean value with the exception of xss() and db_prep(). Those two return a modified version of $string.

Here is an example of form validation:

getErrorMessage());}

include("validation.class.php");
$validation = new Validation;

echo "SELECT * FROM users WHERE user='".$validation->db_prep($validation->database_input)."'";
echo "";

if($validation->email($validation->email)) echo "valid email";
else echo "not valid email";
echo "";

if($validation->phone($validation->phone)) echo "valid phone";
else echo "not valid phone";
echo "";

if($validation->url($validation->url)) echo "valid url";
else echo "not valid url";
echo "";
?>


database input:


email:


phone:


url:

A demo of the above test can be found here.

As you can see from the example above, instead of calling $_GET['username'], you can now call $validation->username without worrying about the data being ‘dirty’.

If you need help using this class, post a comment and I will gladly help you out. Also remember that this class is licensed under the Buy Me Dew License.

In this scenario, you have a custom built blog application that has a section with the latest posts. Instead of constantly pulling this text from the database or saving the output to text files, which can be slow, saving the test into memory may be the best solution.

Take the following code:

$sql = "SELECT * FROM posts ORDER BY date LIMIT 5";
$query = mysql_query($sql);
if(mysql_num_rows($query)
{
     while($row=mysql_fetch_array($query))
     {
          echo "
".$row['title']."

";
     }
}

Lets make that faster.

$memcache = new Memcache;
$memcache->connect('memcache_host', 11211);
if(!$memcache->get('recent_posts'))
{
     $sql = "SELECT * FROM posts ORDER BY date LIMIT 5";
     $query = mysql_query($sql);
     $post_array = array();
     if(mysql_num_rows($query)
     {
          while($row=mysql_fetch_array($query))
          {
               $post_array[] = $row;
          }
     }
    //recent expires in one hour
    $memcache->set('recent_posts',$post_Array, 0, 3600);
}

$recent_posts = $memcache->get('recent_posts');
for($i=0;$i".$recent_posts[$i]['title']."

";
}

You won’t notice a large increase if your site is small, but if you have a busy site and you have a bunch of spare ram, you might as well put it to use. In the future I will show you some more examples of real-world usage of Memcached.

Instead of having two different arrays of data to show a user’s information, you can combine both arrays together with array_merge(). This is one of my favorite php functions as it really saves you hassles.

This:

echo $forum_array['name']." - ".$blog_array['blogpost_count'];

Can become:

echo $user['name']." - ".$user['blogpost_count'];

Not only is it already shorter, but there is less to have to remember. All the data is right there. And to do that all you would need to do is:

$user = array_merge($forum_array,$blog_array);

Of course array_merge() can be used for other things as well, such as combining POST and GET data into a single array (which hopefully you would run an XSS check on it all).

You can view the source of the examples to see how they are done.

Ajax Username Validation with Prototype
Ajax Username Validation with jQuery

note: more examples will come in time. I am currently reading the mootools, dojo, and mochikit.

The only PHP code you will need is as follows:

include("../db.php");
$name = ereg_replace("[^A-Za-z0-9-]", "",mysql_real_escape_string(strip_tags(trim($_GET['name']))));
if(empty($name)) die();

$sql = "SELECT `username` FROM `common_usernames` WHERE `username` = '$name'";
$query = mysql_query($sql,$db);

if(!mysql_num_rows($query))
{
	die(''.$name.' is available!');
}
else
{
	die(''.$name.' is taken!');
}

number = Math.round(Math.random()*10);

Of course you can modify this slightly to fit your needs, but this should be the basics needed.

Edit: As pointed out, the code I supplied is not very random. If you need true random numbers, the mt_rand function supplied by the good guys at phpjs.org is a great solution.

function mt_rand( min, max ) {
    // Returns a random number from Mersenne Twister
    //
    // version: 810.1317
    // discuss at: http://phpjs.org/functions/mt_rand
    // +   original by: Onno Marsman
    // *     example 1: mt_rand(1, 1);
    // *     returns 1: 1
    var argc = arguments.length;
    if (argc == 0) {
        min = 0;
        max = 2147483647;
    } else if (argc == 1) {
        throw new Error('Warning: mt_rand() expects exactly 2 parameters, 1 given');
    }
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

I would suggest using the above when you need to generate random numbers. You should also check out the rest of phpjs.

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php?/$1 [L]

that will allow you to have all the /section/production/2/view/large sections you want without creating additional rewrite conditions. In your index.php script, you can access all of the uri data by simply doing this:

$vars = explode("/",$_SERVER['REQUEST_URI']);

foreach($vars as $value)
{
     echo $value." | ";
}

That will output all of the sections in the uri. Say you want to get a product number and the uri is:

/products/12345/

Grab the product number by getting the second key in the $vars array.

This concept is used in some major open source projects such as WordPress and CodeIgniter.

If you run a large website, you probably should be offsetting your database load. One popular solution is to cache database queries to files on the server’s hardrive. This is not the best way if you are looking for near instant data read times. Memcached stores data into ram, making reading and writing the data very quick.

A simple scenario: You increment the ‘views’ field for a news post. All growing traffic causes a ton of updates which result in locking. Your site becomes slow. Memcached to the rescue!

$memcache = new Memcache;
$memcache->connect('memcache_host', 11211);
if(!$memcache->get('postxyz_123_views'))
{
    //sql to grab number of views

    //number expires in one hour
    $memcache->set('postxyz_123_views',$view_count, 0, 3600);
}
//increment the views
$memcache->increment('postxyz_123_views');

$view_count = $memcache->get('postxyz_123_views');

All you need to do then is run a cron job every hour and have it dump the view counts to the database.

That is basically all there is to using memcached. It is very simple. If you feel adventurous, check out the php documentation for some more advanced features.

It is amazingly simple to limit download speeds with php using no more than a half-handful of built in functions.

To get started, define the download path, filename, and download speed.

$file_path = "/path/to/file/demosong.mp3";
$file_name = "Cool_Song.mp3";
//download speed is in kb/s
$download_rate = 50;

note: you can easily change the download rate on a per-mimetype basis. ex:

if(strstr($file_name,'.mp3'))
{
$download_rate = 30;
}
else
{
$download_rate = 150;
}

Now, check that the file exists and then send some header information.

if(file_exists($file_path) && is_file($file_path))
{
header('Cache-control: private');
header('Content-Type: application/octet-stream');
header('Content-Length: '.filesize($file_path));
header('Content-Disposition: filename='.$file_name);
flush();

note: it is a good idea to leave the flush() in there.

All we have to do now is read the file in chunks. PHP will sleep every second and output the $download_rate to the browser.

$file = fopen($file_path, "r");
while(!feof($file)) {
print fread($file, round($download_rate * 1024));
flush();
sleep(1);
}
fclose($file);
}
else
{
die('Error: The file '.$file_name.' does not exist!');
}

That sums it up. Below is the file code.

$file_path = "/path/to/file/demosong.mp3";
$file_name = "Cool_Song.mp3";
//download speed is in kb/s
$download_rate = 50;
if(strstr($file_name,'.mp3'))
{
$download_rate = 30;
}
else
{
$download_rate = 150;
}
if(file_exists($file_path) && is_file($file_path))
{
header('Cache-control: private');
header('Content-Type: application/octet-stream');
header('Content-Length: '.filesize($file_path));
header('Content-Disposition: filename='.$file_name);
flush();
$file = fopen($file_path, "r");
while(!feof($file)) {
print fread($file, round($download_rate * 1024));
flush();
sleep(1);
}
fclose($file);
}
else
{
die('Error: The file '.$file_name.' does not exist!');
}