PHP, MYSQL, CSS, LINUX TUTORIALS

Add error image when a image is not found

Samuel Marian — Thu, 24 Nov 2011 12:18:35 +0000

When creating a website, a priority is to make your website load faster. That’s good!
But what are you doing if your website is embeding some images who doesn’t exist?

Example:

View Code HTML

If the image (my-image.jpg in our example) doesn’t exist, your website will get loaded more slowly but if you user the .error event from jQuery you can solve this problem easily.

Example:

View Code JAVASCRIPT

$(document).ready(function() {
	$('img').error(function(){
		$(this).attr('src', 'http://example.com/image-not-found.jpg);
	});
});

So this script changes the image source to the error image (image-not-found.jpg) in our example) and your should not have any problem visiting your website.

How to create a Move Up and Move Down button using jQuery

Samuel Marian — Fri, 11 Nov 2011 11:44:22 +0000

I’m sorry i haven’t posted new tutorials for a long time.
And very soon i’ll update the wordpress plugin Maribol IMDB.

So what i would like to teach you today is how to move an element using the powerfull jQuery.

Let’s asume that you want to order the order for some text inputs

HTML structure:

View Code HTML

Javascript:

View Code JAVASCRIPT

    $(document).ready(function() {
        $('.moveUp').click(function(){
            var current = $(this).parent();
            current.prev().before(current);
        });
        $('.moveDown').click(function(){
            var current = $(this).parent();
            current.next().after(current);
        });
    });

View demo here

If you have any question please leave them in the comments section.

Using AJAX and PHP together

Samuel Marian — Sun, 14 Aug 2011 18:21:58 +0000

In this tutorial i’ll show you how to use PHP and AJAX together and get the results that you need.

Here’s an example of a function that executes a ajax request

View Code JAVASCRIPT

function execAjax(type){
   $.ajax({
      url: 'ajax.php?type='+type,
      dataType: 'json',
      success: function( data ) {
         var items = [];
 
         $.each(data, function(key, val) {
            items.push('+ key + '">' + val + '
');
         });
 
         $('#results').html(
            $('', {
               'class': 'results-list',
               html: items.join('')
            })
         );
      }
   });
}

This function should add a list with all the items resulted from the request.

Example of use:

View Code HTML

fruits
vegetables
furniture

And the ajax.php return an array encoded in json.

View Code PHP

$results = array(
   'fruits' => array(
      'apple',
      'bannana',
      'orange'
   ),
   'vegetables' => array(
      'potato',
      'carrot',
      'onion'
   ),
   'furniture' => array(
      'chair',
      'desk'
   )
);
 
$type = $_GET['type'];
 
echo json_encode($results[$type]);

If we’ve clicked on the “fruits” link, will get a result like:

View Code JSON

["apple","bannana","orange"]

This encoded array will be transformed in list with the “each” function from jquery and the result that you should see is:

View Code HTML


   
      apple
      bannana
      orange

Security Tutorial #2: Are you protected against sql injections?

Samuel Marian — Sat, 16 Jul 2011 12:34:42 +0000

There are alot of websites that are vulnerable to sql injections.
In this tutorial i’ll give you some examples with methods to protect you website.

Make your id from url (int)

Let’s assume that you get the id like this:

View Code PHP

   $id = $_GET['id'];

Well with this, your site may be vulnerable.

But if you use like this it will never be vulerable from this variable:

View Code PHP

   $id = (int)$_GET['id'];

Basically this will make your id an id, i mean the value returned is always numeric.

Use the mysql_real_escape_string function
This function may help you alot!

View Code PHP

$city = $_GET['city'];
$sql = mysql_query('SELECT firstname, lastname FROM people WHERE city="'.mysql_real_escape_string($city).'" ');

Note: if magic_quotes_gpc is enabled you should use:

View Code PHP

$city = stripslashes($_GET['city']);
$sql = mysql_query('SELECT firstname, lastname FROM people WHERE city="'.mysql_real_escape_string($city).'" ');

Maribol Personal – WordPress Theme

Samuel Marian — Fri, 15 Jul 2011 22:16:09 +0000

Maribol Personal is a free wordpress theme with a very simple design but it looks pretty.

Demo: here

Download: here