Full On Design

Berkshire Based Web Development

 

PHP

How to use the Filter Functions in PHP

When I started learning PHP (Back in the PHP4 days) validating data was always a pain (for me at least). Most of the resources available cited the POSIX functions as the most effective way of validating an email address or URL.

Thankfully since then, the PHP community has embraced the PCRE functions which are more efficient and are Perl-compatible. However the downside to PCRE (and POSIX for that matter) is that you need to know regular expressions, which for a newbie to learn can feel like walking through a minefield.

Recently though the Filter Functions have become a very popular method to validate data. This is due to their small learning curve.

How to use the Filter Functions

In this example (Using the filter_var() function) the filter function takes the data you input (For example: email@example.com) and will return either the data (if it’s valid) or false (if the data is not valid).

Read the rest of this entry »

URL Shortening Function

Here is a function I use from time to time in my code which I thought I should share. It allows you to quickly shorten URL’s via 6 popular URL shortening websites.

function shorten_url($url, $service=NULL){
		if($service== 'tinyurl'){return get_link('http://tinyurl.com/api-create.php?url='.urlencode($url));}
		elseif($service == 'urly'){return get_link('http://ur.ly/new.txt?href='.urlencode($url));}
		elseif($service == 'isgd'){return get_link('http://is.gd/api.php?longurl='.urlencode($url));}
		elseif($service == 'klam'){return get_link('http://kl.am/api/shorten/?format=text&url='.urlencode($url));}
		elseif($service == 'unu'){return get_link('http://u.nu/unu-api-simple?url='.urlencode($url));}
		else{return get_link('http://api.tr.im/v1/trim_simple?url='.urlencode($url));}
		return $url;
	}

	function get_link($url){
		if(function_exists('curl_init')){
			$ch = curl_init();
			curl_setopt($ch, CURLOPT_VERBOSE, 1);
			curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
			//curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
			//curl_setopt($ch, CURLOPT_POST, 1);
			curl_setopt($ch, CURLOPT_URL, $url);
			$result = curl_exec($ch);
			$resultArray = curl_getinfo($ch);
			if ($resultArray['http_code'] == 200){
				return $result;
			} else {
				return FALSE;
			}
			curl_close($ch);
		}elseif(ini_get('allow_url_fopen') == 1){
			return fopen($url, 'r');
		}
		return FALSE;
	}

/* Usage */
echo shorten_url('http://www.fullondesign.co.uk/');
// returns: http://tr.im/JPCz

PHP Function: realpath()

One functions I wish I had known about when i start learned PHP is the realpath() function. Pretty much what it does is take symbolic link (such as ‘../’ or ‘/’) and returns a canonicalized absolute link (like ‘/home/public_html/folder’). Here is an example of it in action:

<?php
echo realpath('../');
// Would return: /home/mike/www/blogposts
?>

Handling Errors In PHP

Handling errors in PHP can be quite a handful at times. Here is a really simple PHP class which I use to manage errors:

<?php
/*
errors class - Helps management of errors in a script.

@version
	1.0
@author
	Mike Rogers (FullOnDesin.co.uk)
@last updated
	03 June 2009
@usage
	You are free to share, modify and use this code for commercial or non-commercial uses.
	Please give a link back (to http://www.fullondesign.co.uk/ ) if you can, but you don't have you.
	You use this at your own risk.
*/
class errors {
	var $errors_data;

	/*
	Add the error from $new_error into an array of errors.

	@param
		$new_error	string The text related to your error.
	@return:
		True - Error has been Added
	@example
		add_error('Username is Incorrect');
	*/
	public function add_error($new_error){
		$this->errors_data[] = $new_error;
		return TRUE;
	}

	/*
		Outputs the errors.

	@param
		None
	@return:
		- A div (ID - error) which contains the errors.
		NULL - No errors
	@example
		echo output_errors();
	*/
	public function output_errors(){
		if(is_array($this->errors_data)){
			// Cycle through the errors.
			foreach($this->errors_data as $error)	{
				$return .= '<p>'.$error.'</p>';
			}
		// Add it to the error div
		return '<div id="error">'.$return.'</div>';
		}
		return NULL;
	}
}

// @Example - creating the class:
$errors = new errors;

// @Example - Add an error
$errors->add_error('Username is incorrect');

// @Example - Return the errors
echo $errors->output_errors();
?>

If you are looking to fully integrate a script similar to the above, there is a really good post regarding the set_error_handler() function on Tinsology ( PHP Error Handling ).