Tag Archives: Mathematics

Setting Up a Specific Layout for a Zend Action

micro tutorial, PHP, zend framework, , ,

Now that’s really simple! In your action method simply add this line:

$this->view->layout()->setLayout('embed');

Thus the code will look like so:

<?php
 
class IndexController extends Zend_Controller_Action
{
	public function indexAction()
	{
		$this->view->layout()->setLayout('embed');
		// ...	
	}	
}

PHP: The Array Element Doesn’t Exist – Suppress the Warnings

micro tutorial, PHP, , , , , , , , ,

What’s the problem?

If you code PHP from couple of hours you are probably familiar with the following problem:

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<?php
 
	error_reporting(E_ALL);
 
	$arr = array();
 
	echo $arr[3];
 
?>

The first and most common solution is just by adding the isset() statement and the code will look like that:

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<?php
 
	error_reporting(E_ALL);
 
	$arr = array();
 
        if (isset($arr[3]))
	        echo $arr[3];
 
?>

However do you know there’s is another simple and elegant solution? Simply add the @ sign to suppress the element existence

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<?php
 
	error_reporting(E_ALL);
 
	$arr = array();
 
	echo @$arr[3];
 
?>

Zend_Controller_Router_Route_Regex – the Power of Regular Expressions

micro tutorial, PHP, zend framework, , , , , , , , ,

I posted once of custom URLs within Zend Framework, but back than I wasn’t quite sure enough there isn’t a better, more elegant way to do this job. Of course as it appears, there is! With no need to is to use the power of regular expressions with Zend_Controller_Router_Route_Regex. Thus you can match dynamically the URL.

Let’s assume you’d like to have a link with something like www.example.com/3939-some-title-here. This is really very common. So to proceed you’d have to have some regex like:

$pattern = '/\d+-.*/;

So what about Zend Framework

Here the things are going naturally more OOP.

$route = new Zend_Controller_Router_Route_Regex('(\d+)-?(.*)',
                       array('controller' => 'controller_name', 'action' => 'action_name'),
                       array(1 => 'id'));
 
$ctrl->addRoute('my-route', $route);

How to detect a variable existence in JavaScript?

javascript, micro tutorial, , , , , , , , , , , ,

Preface

After reading one of the latest posts from Stoyan Stefanov’s blog – phpied.com I stumbled upon an interesting construction in JavaScript describing how to check an object property existence. I’m going to cover this case using as an example the console object, which comes with the Firebug enabled, and I think it may be very useful, just because this object is widely used, but doesn’t exists over all the browsers, even under Firefox when Firebug is disabled. This construction is known as the IN statement and it looks something like that:

property in object

which I’m going to cover later in details.

How you detect a variable existence?

There are three main ways to detect the existence of a property I see in my practice.

1. The most widely used:

if ( console ) { ... }

2. The second and more professional one:

if ( typeof console != 'undefined' ) { ... }

3. And finally the third and most unknown:

if ( console in window ) { ... }

Of course two of them are wrong! Which one should be changed?

Is everything working correctly? No!

Lets see how they are working. First of all I’m going to test all of them on Firefox 3.6 either with enabled and disabled Firebug, just shouting with old school’s alert().

Now the first one using the IN statement:

if ( console in window )
   alert('object exists!');
else
   alert('object doesn\'t exists!');

With Firebug disabled the answer is … nothing! No alert! That’s because the syntax is wrong. There’s an error within the IF statement. We should modify a bit the first row like that:

if ( 'console' in window )
   alert('object exists!');
else
   alert('object doesn\'t exists!');

Now everything’s OK. With a disabled Firebug the answer is: “object doesn’t exists!”, and after enabling it, normally the “object exists!”.

Lets move on the next example:

if ( console )
   alert('object exists!');
else
   alert('object doesn\'t exists!');

With Firebug enabled the answer is as we expect: “object exists!”, but after disabling it yet again – nothing?! Why’s that? Because the console object doesn’t exists anymore and the IF statement doesn’t return true or false, but simply crashes. How to modify the code? Simply by adding a window.console instead of console.

if ( window.console )
   alert('object exists!');
else
   alert('object doesn\'t exists!');

Than the answer is: “the object doesn’t exists!” after what we expected!

The third method is the mostly used, just because it’s completely clear what’s the goal of the IF statement:

if ( typeof console != 'undefined' )
   alert('object exists!');
else
   alert('object doesn\'t exists!');

In both disabled and enabled Firebug the answer is as expected!

Now the IN statement may be used if not for the console, but for checking the existence of a property of within an object.