FROST

Creating your own library in CodeIgniter

admin — Sun, 03 Feb 2008 18:12:56 +0000

Creating your own library in CodeIgniter

You setup CodeIgniter and you see how it really helps your life as a developer doing you job. But you want your codes to be reusable into your other projects. Yes you can say i'll just copy-paste the codes, but there's more elegant idea, build it as a library. What is a library, IMO, a library is a file or a component that can be easily inject into an existing system.

Nuf said, here's the code:

/**
* class for easy uploading of files for CI
* @author zeratool
* @uses CI::Upload class
*
*/

class lib_upload
{
function __construct()
{
$config['upload_path'] = '/your/path/to/upload/dir/';
$config['allowed_types'] = 'gif|jpg|png';

$this->CI =& get_instance();
$this->CI->load->library('upload', $config);
}

/**
* uploads the file
* @access public
*
*/
function do_upload()
{
$data = $this->validate();
return $data;
}

/**
* cehcks the file uploaded
* @access private
* @return mixed, string if error, array of file uploaded info on success
*/
private function validate()
{
if (! $this->CI->upload->do_upload())
{
return $this->CI->upload->display_errors();
}
else
{

return $this->CI->upload->data();
}
}

}

Now in order to use our library, we have to create our Controller and View files.

First, the controller:

class upload extends Controller
{
function __construct()
{
parent::Controller();

//we use our custom library by loading it first
$this->load->library('lib_upload');
}

function index()
{
// we load our view file here, in our case it's the upload form
$this->load->view('uploadform');
}

function do_upload()
{
// we call the do_upload method of our library
$ok = $this->lib_upload->do_upload();

// we checked if the upload is successful or not
// if it displays the array of the file information, try to check your
// upload directory and look for the file there
// NOTE : you must set the upload dir enough write priveledges

echo '

';

print_r($ok);
}

}
?>
Here's our View  file




Upload Form

Blog title changed

admin — Fri, 25 Jan 2008 20:34:46 +0000

"Frameworks that work" was the old title of this humble blog. I switched to "FROST!" so I can write anything open source. Hoping for more frequent postings.

PHP Caching using Memcached

admin — Thu, 24 Jan 2008 21:14:26 +0000

Why cached? It's simple, you want speed. How? Say you have search application on your php webapp that yields thousands of results. Of course these are divided in a nice paginated links. Without caching, everytime the user jumps from each paged result links, your app will query your database, which adds overhead.

By using caching, you're storing the result set in a temporary container(in case of memcached, it's the memory) so that only one call to the DB are done.

Here's the logic.

1. First check if we have cached the result set coming from DB.

2. If not, run the query.

3. Now, save the result set into cache.

4. If yes(see #2), get the result set from the cache.

Why Memcached? Well IMHO, it's fast and it's supported by php using libmemcache. You can see the complete details and can download it from danga.com

Can you provide sample snippet? See below.

// first we set up memcached connection

$memcache_obj = new Memcache;
$memcache_obj->connect($memcache_host, 11211);

// now let's check for cached data

if(!$memcache_obj->get('unique_key')) {

// your very large query here and assign the result in $resultset

// save the db result into the cache, set the cache lifetime for 5 minutes(60 sec * 5)

$memcache_obj->set('unique_key', $resultset, MEMCACHE_COMPRESSED, 300);

} else {

$resultset = $memcache_obj->get('unique_key');

}

// do useful things with the $resultset

It's so simple , yet so helpful.

CodeIgniter 101

admin — Mon, 10 Dec 2007 06:25:28 +0000

You want to use codeigniter but don't know where to start? Below are the lists to get you up and running.

1. Download the zip/tar package at http://codeigniter.com/ , click the link "Download Codeigniter" or click here

2. Extract the files under your document root, on windows if you are using wamp5, it's under c:\wamp\www, on linux, the default is under "/var/www". Create a folder say "CodeIgniter" and put all the files here.

3. You're done! Fire up your browser and open the url "http://localhost/CodeIgniter/" and you will see a welcome page saying "Welcome to CodeIgniter". You can see the screenshot below.