Tag Archives: Technology/Internet

PHP if-else-endif Statements

PHP: if

A typical web developer knows exactly how a PHP if statement looks like:

   if ( expression ) {
      // if the expression was true proceed here
   } else {
      // there was a false expression
  }

HTML mess with PHP

When it comes to merge PHP and HTML the things are becoming ugly. Indeed most of the template systems as Smarty are improved and developed to overcome this issue, however when working with a native PHP code with no template system or with template system where the PHP code is allowed the things are really bad.

Let me show this in a breve example. Image you have to show different formatted HTML depending on a PHP expression. Something like that

<?php if (expression) { ?>
<div class="message">OK. Your registration is successful</div>
<?php } else { ?>
<div class="error">Something went wrong! Please try again later! </div>
<?php } ?>

Now you can see how difficult to maintain this code is when it doesn’t make use of only one code of HTML markup. Imaging you’ve to print differently formatted tables! Indeed the PHP curly brackets are different to follow.

PHP: the different IF syntax

So there is a PHP syntax that tries to help you manage this. You can write more human readable code like this:

<?php if ( expression ) : ?>
<div>message goes here</div>
<?php endif ?>

Thus you get the ENDIF instead of only one curly bracket. That’s indeed readable enough. In fact you can use this syntax with any conditional or loop statement in PHP:

<?php foreach($array as $key => $val) : ?>
<div class="message"><?php echo $val ?></div><br />
<?php endforeach ?>

To return in the previous example the code above should be transformed in that:

<?php if ( expression ) : ?>
<div class="message">some message here!</div>
<?php else : ?>
<div class="error">some error here!</div>
<?php endif ?>

PHP: detecting mobile device

HTTP_USER_AGENT

Beside that most of the responses of $_SERVER[‘HTTP_USER_AGENT’] may return, it appears that this is the most reliable way to track down a user agent with PHP. It is weird that most of the clients, i.e. Safari and Chrome will return something with Mozilla in it’s strings, but however it’s enough to track the “chrome” or “safari” sub strings.

All the examples bellow are from Mac OS X:

Firefox 3.6:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

Note: there are both Mozilla and Firefox sub strings!

Safari 4:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; bg-bg) AppleWebKit/531.21.8 (KHTML, like Gecko) Version/4.0.4 Safari/531.21.10

Chrome:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; en-US) AppleWebKit/532.9 (KHTML, like Gecko) Chrome/5.0.307.11 Safari/532.9

Note: Here they are Mozilla, Chorme and Safari!!!

Opera:

Opera/9.80 (Macintosh; Intel Mac OS X; U; en) Presto/2.2.15 Version/10.10

The day of mobile

Nowadays it’s normal to make a site with the presumption it will be visible from mobile. The war between Nexus One from Google and iPhone from Apple is just beginning and with all those devices with wide screens everything’s becoming more complicated.

User agent strings from Nexus One and iPhone

Both are weird, but both contain the keyword – “mobile” and that may help you make a check with something like this PHP snippet:

<?php
$mobile = !!(FALSE !== strstr(strtolower($_SERVER['HTTP_USER_AGENT']), 'mobile'));
?>

CSS right to left direction & floating elements

direction:rtl

When developing a website for Arabic one of the most common questions is how to get it work with a reverse direction. Actually there is the CSS property direction:

.my-class {
    direction:rtl;
}

which makes the page right aligned.

Floating elements …

However sometimes there are elements on the page which are absolutely positioned and the direction property doesn’t do the job. The solution is something like combining the two settings. Both direction and float. So something like:

.my-class {
    float:left;
}

becomes something like:

.my-class {
    float:right;
    direction:rtl;
}

and of course if you’ve something like margin-left it should become margin-right!

Video sites must use … mp4 and only mp4!

H.264

Yes it may sound strange, but now with the upcoming HTML5 features every browser again is playing its own game. Firefox and Opera support only OGG Theora, Chrome and Safari only MP4 and what about IE .. it doesn’t support anything. Than why should we convert to mp4 with h.264 codec?

Because everybody is playing flash

And that’s again very sad but at least the flash players are playing mp4 with this encoding, which is good because this file will be playable under most of the mobiles. And if you have a large video site to support why don’t you convert to mp4 and play it with a Flash Player and give the opportunity to play mp4 on mobile.

Only one file under the sky

Thus you gain to keep only one file – playable under every device?

YouTube and FLV

Now I wonder why YouTube have both FLV and MP4 formats?

Of course if you’d like to be perfect …

Convert every video to MP4, FLV and OGG, but that means 3 files for every video?!

Does Firefox play mp4 h.264 within the HTML5 video tag?

As Firefox has declared it will play only open formats within the HTML5 video tag support. But however is there any way to play video with the mp4 h.264 codec under FF with no plugin support?

That is the question.