arkinEx Codex » PHP

PHP Function: array_trim

arkin — Wed, 04 Nov 2009 20:39:07 +0000

I was loading alot of data from .csv files, some of the data was blank and i didnt want array key=>values for it, so i created an multi dimensional array cleansing tool.

function array_trim(&$a){
	foreach( $a as $k => $v )
	{	
		if ( is_array( $a[$k] ) ) array_trim( $a[$k] );
		else $a[$k] = trim( $v );
		if ( empty($a[$k]) ) unset( $a[$k] );
	}
} 
// Useage:
array_trim( $a );

Have fun.

Convert time (hr:min:secs) into seconds

arkin — Sun, 14 Sep 2008 23:33:47 +0000

I wrote this snippet to convert ffmpeg’s information output time into seconds, i can then determine the 25, 50 and 75 percentages to create 3 different thumbnails of a movie (using ffmpeg also).

Heres the snippet:

function time2seconds($time='00:00:00'){
  list($hr,$m,$s) = explode(':', $time);
  return ( (int)$hr*3600 ) + ( (int)$m*60 ) + (int)$s;
}

Hope you find this as useful as I have.

Automatically Version your Javascript & Stylesheets

arkin — Mon, 04 Aug 2008 17:34:06 +0000

Recently, I was browsing the internet, as you do, and I came across a great little article that discussed the automatic versioning of stylesheets, javascript, flash and image files.

As i constantly have to hold shift when refreshing to get a full page refresh, I decided this method was genius and decided there were a few things needed to make it perfect.

First of all, I couldn’t get the cache code which goes in .htaccess to work, after closer inspection you must make sure mod_expires is enabled on your server (if you run your own), otherwise you will see a 500 error.

Secondly, the autoVer ended up breaking my javascript and stylesheet files as I name them with multiple periods and it was subsequently replacing them all with numbers so i ended up with filenames like framework.1230203232.version.21302302.two.js which is a bit over the top.

Anyway, this is my revised version, for those of you who haven’t read Particletree, you don’t necessarily need to, I will cover all the required parts.

First of all, we modify .htaccess so that it sets an expiry date on all stylesheets, images and javascript files.

.htaccess


    ExpiresActive On
    ExpiresDefault "access plus 10 years"

#Rules for the versioned files
RewriteRule ^(scripts|css|images)/(.+)\.([a-zA-Z0-9]+)\.(js|css|jpg|gif|png)$ $1/$2.$4 [L]

This will make all images, stylesheets, flash and javascript cache for 10 years (reduces load on your server and bandwidth costs) and also adds the RewriteRule which handles the version file pointing to the normal files.

Next, we want to add the function, ideally you want this defined on every page, so stick it somewhere good.

the Auto Version function

function autoVer($f){
    if (!file_exists($_SERVER['DOCUMENT_ROOT'].$f)) return $f
    return substr($f,0,strrpos($f,'.')+1).base_convert(filemtime($_SERVER['DOCUMENT_ROOT'].$f),10,36).substr($f,strrpos($f,'.'));
}

In the case that php cannot find the file, it still might exist, so the function just returns the parameters it was given.

Next, we rewrite the HEAD part of your html, this file must be PHP for it to work, and the function must be included (either at the top of the page or within another file).

My HEAD area

&lt;head&gt;
&lt;title&gt;arkinEx.com - Autoversion Your Javascript &amp; CSS Stylesheets&lt;/title&gt;
&lt;meta http-equiv="content-type" content="text/html; charset=UTF-8" /&gt;
&lt;meta name="author" content="arkinEx" /&gt;
&lt;link rel="stylesheet" type="text/css" href="<?=autoVer('/resources/stylesheets/design.css')?>" /&gt;
&lt;script type="text/javascript" src="<?=autoVer('/resources/javascript/mootools-core.js')?>"&gt;&lt;/script&gt;
&lt;script type="text/javascript" src="<?=autoVer('/resources/javascript/mootools-more.js')?>"&gt;&lt;/script&gt;
&lt;script type="text/javascript" src="<?=autoVer('/resources/javascript/mootools-pastejax.js')?>"&gt;&lt;/script&gt;
&lt;/head&gt;

Which, then, will produce a nice output something like this:






You get the idea, so try it out, let me know how you found it.
The Original Article: “Automatically Version Your CSS and Javascript Files“.

Benchmark your PHP code

arkin — Mon, 04 Aug 2008 11:51:44 +0000

As a developer I often question myself when I have many occurrences of a function that could be replaced by something else. There are often many ways of achieving the same thing and only opinion standing in the way of a decision.

To solve this problem, I often benchmark certain peices of code multiple times to see which comes out the fastest. In this guide/tutorial I will teach you how to benchmark your own code.

The first step is to decide what you want to benchmark, I had trouble in figuring out what to test in this benchmark so in this example I am going to do a simple comparison of using sizeOf inside a for loop and outside a for loop.

The second step is to decide how many times you want to repeat a block of code, if its a larger and more intense block I sugget fewer times, for a shorter block, i recommend more times. In this example I have done 100 times to produce a noticably different output time.

The first part of the code which uses sizeOf inside the for loop:

$start = microtime(true);
for ($i = 0; $i < 100; $i++) {
/* PUT THE CODE TO BENCHMARK BELOW */
 
	$x = range(1,25);
	for ($a=0;$a<sizeOf($x);$a++);
 
/* END OF BENCHMARK CODE */
} unset($start,$i,$x,$a,$s);
printf('%01.2fms'."\n",(microtime(true)-$start)*1000);

Notice, it is important to unset the variables that were set during the test to make it fair.

The second test will be with the sizeOf element outside of the for loop.

$start = microtime(true);
for ($i = 0; $i < 100; $i++) {
/* PUT THE CODE TO BENCHMARK BELOW */
 
	$x = range(1,25);
	$s = sizeOf($x);
	for ($a=0;$a<$s;$a++);
 
/* END OF BENCHMARK CODE */
} unset($start,$i,$x,$a,$s);
printf('%01.2fms'."\n",(microtime(true)-$start)*1000);

Also, notice, the only thing that changed here was the addition of $s = sizeOf($x); and the changed variable in the for loop.

The ouput of this test was quite significant:

2.06ms
0.96ms

As you can see from the results, the sizeOf is best kept outside of the for loop (cached in a variable), so it is not repeated each time.

I hope this guide has helped, I will post the file online later for download and will be doing a more advanced guide on benchmarking in the next few days.