phpied.com

This posts is one of those "note to self" kinda posts. I just finished installing PHP and Apache on my Mac OS 10.5.6 and though I should document the experience should I (or you) need to do it again.

It could already be there

The default OS install came with goodies like ruby and php already there. So I could use php on the command line already. But it wasn't "hooked" to Apache for proper web development.

Also turns out Mac comes with some version of Apache, looks like it's disabled by default, but if it isn't, disable it from System Preferences / Sharing / Web Sharing.

Now let's start fresh with PHP5 and Apache 2, ignoring the PHP that's already there.

Mac ports prerequisite

Mac ports makes installing many software packages a breeze on the Mac. If you don't have it already, do set up Mac ports first.

Ready? Set? Go

1. Log into the mac ports prompt:

   $ sudo port
   Password:
   MacPorts 1.700
   Entering interactive mode... ("help" for help, "quit" to quit)
   [Users/stoyan] >

2. inside the Mac ports prompt simply do:

   [Users/stoyan] > install php5

3. This is it! Give it a bit of time to pull out all dependencies, including Apache2. The rest is just some configuration...
4. Start Apache and make it start when you power on the computer next time:

   $ sudo launchctl load -w /Library/LaunchDaemons/org.macports.apache2.plist

5. Test that Apache runs fine by pointing your browser to http://localhost/. You should see a page that says "It works!"
6. Tell Apache that PHP exists:

   $ sudo /opt/local/apache2/bin/apxs -a -e -n "php5" libphp5.so
   [activating module `php5' in /opt/local/apache2/conf/httpd.conf]
   

7. Create a php.ini file (PHP configuration) by copying the default .ini

   sudo cp /opt/local/etc/php.ini-dist /opt/local/etc/php.ini

8. If you need Apache stuff, like config files, error/access logs, htdocs... look around /opt/local/apache2. The web root for example is /opt/local/apache2/htdocs. I found it kinda convoluted so decided to move the web root to my home directory. So next two steps are optional.
9. I'll store all web apps and pages and scripts in a directory called /localhost in my home directory:

   mkdir ~/localhost

10. Time to edit the Apache config to tell it about the new location of the web root. Open httpd.conf

    sudo vi /opt/local/apache2/conf/httpd.conf

    Search for "DocumentRoot" and replace the current value /opt/local... with /Users/[your username]/localhost.
    The result would be like:

    DocumentRoot "/Users/stoyan/localhost"

    Then do the same further down in the config where it says <Directory..., so it should read:

    #
    # This should be changed to whatever you set DocumentRoot to.
    #
    <Directory "/Users/stoyan/localhost">
    

11. Apache also need to know that files that end with .php will be handled by the php module, so edit httpd.conf (the same one from the previous step). Search for "php" and you'll find:

    LoadModule php5_module        modules/libphp5.so

    Add one more line so it looks like:

    LoadModule php5_module        modules/libphp5.so
    AddHandler application/x-httpd-php .php

12. restart Apache (see below) and you're all done

start/stop/restart Apache

Here's how you start/stop/restart Apache:

• $ sudo /opt/local/etc/LaunchDaemons/org.macports.apache2/apache2.wrapper start

• $ sudo /opt/local/etc/LaunchDaemons/org.macports.apache2/apache2.wrapper stop

• $ sudo /opt/local/etc/LaunchDaemons/org.macports.apache2/apache2.wrapper restart

Or to stop and disable starting up every time you power on:

$ sudo launchctl unload -w /Library/LaunchDaemons/org.macports.apache2.plist

Verify that all is good

You can check that all is good by creating a PHP info script.

echo "<?php phpinfo(); ?>" > ~/localhost/test.php

Now point your browser to http://localhost/test.php. It should give you the php info page (a looong page of PHP-related information)

Was having fun today with idiff.php - a PHP shell script to tell you if two images are visually different by comparing them pixel by pixel. If there's a difference, the script creates a third image - black background with the different pixels in green. Only after writing the script I found that there's an imagemagick command compare that does the same

the script

The idea is that two GD images are created from the input files, also a third GD image with black background to store the diff. Loop through all the pixels and compare them one by one. If one is different, write a green pixel at the same location of the diff image.

<?php
/**
 * Shell script to tell if two images are identical.
 * If not, a third image is written - black background with the different pixels painted green
 * Code partially inspired by and borrowed from http://pear.php.net/Image_Text test cases
 */

// check if there's enough input
if (empty($argv[1]) || empty($argv[2])) {
    echo 'gimme at least two image filenames, please.', "\n";
    echo 'e.g. "php idiff.php img1.png img2.png"';
    echo "\n", 'third filename is the image diff, optional, default is "diffy.png"';
    exit(1);
}

// create images
$i1 = @imagecreatefromstring(file_get_contents($argv[1]));
$i2 = @imagecreatefromstring(file_get_contents($argv[2]));

// check if we were given garbage
if (!$i1) {
    echo $argv[1] . ' is not a valid image';
    exit(1);
}
if (!$i2) {
    echo $argv[2] . ' is not a valid image';
    exit(1);
}

// dimensions of the first image
$sx1 = imagesx($i1);
$sy1 = imagesy($i1);

// compare dimensions
if ($sx1 !== imagesx($i2) || $sy1 !== imagesy($i2)) {
    echo "The images are not even the same size";
    exit(1);
}

// create a diff image
$diffi = imagecreatetruecolor($sx1, $sy1);
$green = imagecolorallocate($diffi, 0, 255, 0);
imagefill($diffi, 0, 0, imagecolorallocate($diffi, 0, 0, 0));

// increment this counter when encountering a pixel diff
$different_pixels = 0;

// loop x and y
for ($x = 0; $x < $sx1; $x++) {
    for ($y = 0; $y < $sy1; $y++) {

        $rgb1 = imagecolorat($i1, $x, $y);
        $pix1 = imagecolorsforindex($i1, $rgb1);

        $rgb2 = imagecolorat($i2, $x, $y);
        $pix2 = imagecolorsforindex($i2, $rgb2);

        if ($pix1 !== $pix2) { // different pixel
            // increment and paint in the diff image
            $different_pixels++;
            imagesetpixel($diffi, $x, $y, $green);
        }

    }
}

if (!$different_pixels) {
    echo "Image is the same";
    exit(0);
} else {
    if (empty($argv[3])) {
        $argv[3] = 'diffy.png'; // default result filename
    }
    imagepng($diffi, $argv[3]);
    $total = $sx1 * $sy1;
    echo "$different_pixels/$total different pixels, or ", number_format(100 * $different_pixels / $total, 2), '%';
    exit(1);
}
?>

usage

Type in the command line something like:

php idiff.php img1.png img2.png result.png

This command will compare img1.png with img2.png. If they are not the same dimensions, will exit with error code. If their pixels exactly the same will exit with success code 0 and print a success message. If the images are not the same, will write the file result.png.

If you omit result.png, the generated file will be called diffy.png

example

img1.png:

img2.png

running the command:

>php idiff.php img1.png img2.png
70/24600 different pixels, or 0.28%

the result diffy.png:

imagemagick

yep, so after I did this I found that imagemagick has a command called compare that does the same, only with more features, like the -fuzz option for example that allows you to specify how different should the pixels be, in order to consider them important.

the command:

>compare img1.png img2.png diffy-im.png

the diffy-im.png result

As you can see the different pixels are red and the actual image is a very pale background. Nice.

It's that time of the year again. Time to cast my vote as part of the jury in Packt's open-source awards, category "PHP CMS".

(for my last year's rant, check the internet archive copy)

How to judge a CMS?

How to judge a CMS? Tough one. How do you judge any piece of software anyway?

Features? Usually any system or product lists the features in way meant to wow you, I mean a list of features always looks nice, it's a sales tool. And the features don't mean that much, actually some say, you should underfeature the competition. Of course, you can't take that to the extreme and build software that does nothing. You need features, but the best CMS doesn't mean the one with the most features, neither the one with less. You just need the right mix and "right" may wildly vary depending on the task. Are you building an e-commerce site, a library of articles, a 5-page business card-like site, on online community? No way to judge a system without an idea of what you want it to do for you. And no way what you want to do is what everyone else wants to do.

Quality? This is much easier. Does the code validate, YSlow score, accessibility, etc. Easy, even automated, but again, the system can be written beautifully but doesn't do the right thing or work the right way.

Documentation? A must-have, usually a problem with any software. Can be too specific in areas that don't matter and completely lacking where you really need it. Or outdated. It's also nice to have some books, sign that the system is relatively popular, mature and at the end of it, it's cozier to share the couch with a book then with an online text. Also API documentation, at least it's easier to generate and keep updated.

Community? Very important, you'll inevitably have questions when you start working with the system. It would be nice to have a friendly place where you can ask/answer questions. But how do you judge a community? The only way is to get involved and spend time. No way to do this when you're judging 5 systems in a matter of days.

Verdict

It's virtually impossible to judge any piece of software until you start using it. It may have the right features, but they might be unfriendly or virtually unusable. It may have documentation, but not the one you need, etc, etc. So the only way is to spend time with the software and try to make it work for you.

And since I've been meaning to create my personal stoyanstefanov.com, I thought it would be a good idea to kill two birds with one stone - cast my vote and have a working site at the end, powered by my personal CMS favorite.

Content

So I sit down and listed the features I need, nothing overly complicated, and also decided on some rough structure. Here's my feature list:

• Blog. In English and also in Bulgarian, nice test for i18n capabilities
• Photos
• Syndicated Twitter feed, probably the CMS will not have it out of the box, but syndicating content and consuming web services is so common these days that the software better be capable of doing it easily or let me write an extension easily
• Slides, with the help of Slideshare's API, same as above
• Books - a page for each book maybe, reviews, image, etc
• Projects - list of stuff I'm involved in
• Publications - articles I wrote for other sites and magazines
• Conferences - list the conferences I've spoken to, encourage people to invite me, bio blurb, hi-res photo
• About
• Contact
• Social - links to facebook profile, linked in, etc
• Sites - other sites of mine
• Syndicated content - again, syndicate friendfeed or a Yahoo pipe that contains pretty much all my online activity, such as other blogs and even tiny things like last.fm love/hate ratings
• Subscribe - option to subscribe to RSS feeds or even monthly email
• custom 404

All these features I would combine in 5 top-level menu items: blog, news, writing, speaking, info.

Checklist

So now that I know what I want to build, I can go ahead and (attempt to) do it with each CMS while looking out for some pre-defined checks.

Info

URL:
Maturity: (since when the CMS exists)
Frequency of new releases: (is the project active)

Tasks

The best way to get a feeling of the software is by performing some tasks, the same tasks for all CMS

1. Download
2. Install
3. setup friendly urls
4. setup sections and content
5. customize presentation
6. customize homepage
7. create an extension
8. customize 404

QA

Test both the front-end and the back-end admin sections.

• works without js
• works without css
• validates html
• validates css
• jslint
• yslow grade
• smush.it

Misc

• Is there a WYSIWYG, people like those (I avoid them)
• available extensions
• available themes
• Documentation
• API docs
• Community
• Books

Whew!

Lotsa stuff, wish me luck with aaall that And I would be interested to hear any comments on the subject. Thanks for reading!

I'll be speaking at the php|works and pyWorks conferences in Atlanta, Georgia in November, they'll be held together and there is a central track that has topics of interest to both phpiers and pythonistas, this is where I come in.

The conference(s) schedule is here and this is me: "Image optimization for the web"

This is a sort of a catch-up post for listing what I've been up to lately.

• YUI Blog just published my first article, I'm so proud. It's about loading JavaScript in non-blocking fashion, because JavaScripts, they, you know, like, block downloads. Luckily, there's an easy fix - DOM includes, which I've previously discussed, discussed and discussed.
• SitePoint published an update to my older article that introduces AJAX, ok, Ajax, by creating a command-line-like interface with PHP on the server side. The updated article features improved code, jQuery example, YUI example, JSON discussion and example. Check it out, bookmark and recommend to your friends that keep asking you "What's this AJAX (they are new, don't know it's now spelled "Ajax") thing? Do you know of a good article?"
• YDN (developer.yahoo.com) published a video presentation of me and my lovely teammate Nicole Sullivan where we talk about some new and cool front-end performance techniques. So if you wandered how I look and are eager to hear my fabulous Balkan peninsula accent, give it a shot. The talk is called "After YSlow 'A'" and is targeted at those of you who have reached performance nirvana, but are still hungry for more. We talk about preloading components, post-loading, javascript, images, using flush() in PHP to send first byte early on and other fun stuff.
• Last, not least, I decided to try and find some time to update my JavaScript patterns site. Unfortunately I got sidetracked (yep, I'm easily distracted by shiny objects) and played with a not-so-javascript pattern. The post I published (includes a pretty lame screencast! and) demonstrates how you can use animated background position to indicate loading progress.

Whew, c'est tout pout ce moment, expect a lot more now that the JavaScript book is out of the way. Ah, yep, if you feel like it, join me on Facebook, I created a JS book page.

One of Yahoo's performance rules says: Use cookie-free domains for static components. This is good because the server has no use for cookie information when serving a JPEG or another static component, so all this cookie information creates network traffic for no reason.

One of the implications of following the rule is related to the whole www vs no-www question. Basically you should always use www if you're planning to use any other sub-domains and you want them cookie-free. This is because you have no way to set a cookie only to the top-level domain. So for example you cannot write a cookie only to phpied.com. If you load component from img.phpied.com, the cookie from phpied.com will be sent again. In Firefox this doesn't seem to be the case, but in IE it is.

Here are two test scripts that demonstrate the behavior:

• http://phpied.com/nowww.php
• http://www.phpied.com/yeswww.php

Load both of these pages and then reload them to see what cookies are sent. They both try to set cookies in all possible ways:

1. omitting the domain name
2. .domain.com
3. domain.com
4. www.domain.com

Here's the source code of the files:

nowww.php [test]

<?php
setcookie('no0', 'no www, no domain');
setcookie('no1', 'no www, .phpied.com', 0, '/', '.phpied.com');
setcookie('no2', 'no www, phpied.com', 0, '/', 'phpied.com');
setcookie('no3', 'no www, www.phpied.com', 0, '/', 'www.phpied.com');

echo '<pre>';
print_r($_COOKIE);
?>

yeswww.php [test]

<?php
setcookie('yes0', 'yes www, no domain');
setcookie('yes1', 'yes www, .phpied.com',    0, '/', '.phpied.com');
setcookie('yes2', 'yes www, phpied.com',     0, '/', 'phpied.com');
setcookie('yes3', 'yes www, www.phpied.com', 0, '/', 'www.phpied.com');

echo '<pre>';
print_r($_COOKIE);
?>

Loading the two pages twice shows how in IE, no0, no1, and no2 are all visible when using www as well as when not using it. In Firefox it's almost the same, only that no0 is not visible when using www.

As a take-home:

• use www
• write cookies to the appropriate domain level (e.g. don't write to *.domain.com)

Philip "Bluesmoon" Tellis has posted a tiny (under 3K minified) JavaScript library to format dates, inspired by PHP's strftime()

Examples:

d.strftime('%Y/%m/%d')
» en: 2008/04/25
» fr: 2008/04/25
» de: 2008/04/25

d.strftime('%A, %d %B')
» en: Friday, 25 April
» fr: Vendredi, 25 Avril
» de: Freitag, 25 April

There's also a demo to fiddle with.

I've previously had fun with kinda like the opposite: translating human-readable times into JS Date objects. Also here and here you have strtotime() look-alikes that take human-readable dates and turn them into Date objects.

The basic idea of a Web 2.0-style "mashup" is that you consume data from several services, often from different providers and combine them in interesting ways. This means you often need to do more than one HTTP request to a service or services. In PHP if you use something like file_get_contents() this means all the requests will be synchronous: a new one is fired only after the previous has completed. If you need to make three HTTP requests and each call takes a second, your app is delayed at least three seconds.

Solution

An improvement of course is to cache responses as much as possible, but at one point or another you still need to make those requests.

Using the curl_multi* family of cURL functions you can make those requests simultaneously. This way your app is as slow as the slowest request, as opposed to the sum of all requests. And that's something.

A function

Here's a little function I coded that will allow you do multi requests.

<?php

function multiRequest($data, $options = array()) {

  // array of curl handles
  $curly = array();
  // data to be returned
  $result = array();

  // multi handle
  $mh = curl_multi_init();

  // loop through $data and create curl handles
  // then add them to the multi-handle
  foreach ($data as $id => $d) {

    $curly[$id] = curl_init();

    $url = (is_array($d) && !empty($d['url'])) ? $d['url'] : $d;
    curl_setopt($curly[$id], CURLOPT_URL,            $url);
    curl_setopt($curly[$id], CURLOPT_HEADER,         0);
    curl_setopt($curly[$id], CURLOPT_RETURNTRANSFER, 1);

    // post?
    if (is_array($d)) {
      if (!empty($d['post'])) {
        curl_setopt($curly[$id], CURLOPT_POST,       1);
        curl_setopt($curly[$id], CURLOPT_POSTFIELDS, $d['post']);
      }
    }

    // extra options?
    if (!empty($options)) {
      curl_setopt_array($curly[$id], $options);
    }

    curl_multi_add_handle($mh, $curly[$id]);
  }

  // execute the handles
  $running = null;
  do {
    curl_multi_exec($mh, $running);
  } while($running > 0);

  // get content and remove handles
  foreach($curly as $id => $c) {
    $result[$id] = curl_multi_getcontent($c);
    curl_multi_remove_handle($mh, $c);
  }

  // all done
  curl_multi_close($mh);

  return $result;
}

?>

Consuming

The function accepts an array of URLs to hit and optionally an array of cURL options if you need to pass any. The first array can be a simple indexed array or URLs or it can be an array of arrays where the second has a key named "url". If you use the second way and you also have a key called "post", the function will do a post request.

The function returns an array of responses as strings. The keys in the result array match the keys in the input.

A GET example

Let's say you want to use some Yahoo search web services (consult YDN) to create a music artist band-o-pedia kind of mashup. Here's how you can search audio, video and images at the same time:

<?php

$data = array(
  'http://search.yahooapis.com/VideoSearchService/V1/videoSearch?appid=YahooDemo&query=Pearl+Jam&output=json',
  'http://search.yahooapis.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&query=Pearl+Jam&output=json',
  'http://search.yahooapis.com/AudioSearchService/V1/artistSearch?appid=YahooDemo&artist=Pearl+Jam&output=json'
);
$r = multiRequest($data);

echo '<pre>';
print_r($r);

?>

This will print something like:

Array
(
    [0] => {"ResultSet":{"totalResultsAvailable":"633","totalResultsReturned":...
    [1] => {"ResultSet":{"totalResultsAvailable":"105342","totalResultsReturned":...
    [2] => {"ResultSet":{"totalResultsAvailable":10,"totalResultsReturned":...
)

A POST example

There's an interesting Yahoo search service called term extraction which analyses content. It accepts POST requests. Here's how to consume this service with the function above, making two simultaneous requests:

<?php
$data = array(array(),array());

$data[0]['url']  = 'http://search.yahooapis.com/ContentAnalysisService/V1/termExtraction';
$data[0]['post'] = array();
$data[0]['post']['appid']   = 'YahooDemo';
$data[0]['post']['output']  = 'php';
$data[0]['post']['context'] = 'Now I lay me down to sleep,
                               I pray the Lord my soul to keep;
                               And if I die before I wake,
                               I pray the Lord my soul to take.';

$data[1]['url']  = 'http://search.yahooapis.com/ContentAnalysisService/V1/termExtraction';
$data[1]['post'] = array();
$data[1]['post']['appid']   = 'YahooDemo';
$data[1]['post']['output']  = 'php';
$data[1]['post']['context'] = 'Now I lay me down to sleep,
                               I pray the funk will make me freak;
                               If I should die before I waked,
                               Allow me Lord to rock out naked.';

$r = multiRequest($data);

print_r($r);
?>

And the result:

Array
(
    [0] => a:1:{s:9:"ResultSet";a:1:{s:6:"Result";s:5:"sleep";}}
    [1] => a:1:{s:9:"ResultSet";a:1:{s:6:"Result";a:3:{i:0;s:5:"freak";i:1;s:5:"sleep";i:2;s:4:"funk";}}}
)

Writing readable code means proper indentation. Usually you'd tab (or use 2 or 4 or 3 spaces) after every curly bracket. Something like this:

if (true) {
    // indent
    if (false) {
        // another indent
        // and some more
    }
}

Same goes when you have a bigger hash/object sort of thing:

var memememe = {
    name: 'Stoyan',
    family_name: 'Stefanov',
    blog: 'http://www.phpied.com',
    kids_count: 2,
    books_count: 3,
    occupation: 'programmer'
}

Sometimes I find myself going a little fancy and aligning all the values in the name/value pairs:

var memememe = {
    name:        'Stoyan',
    family_name: 'Stefanov',
    blog:        'http://www.phpied.com',
    kids_count:  2,
    books_count: 3,
    occupation:  'programmer'
}

But recently, inspired by Firebug's Net panel way of presenting header information, I tried aligning the keys to the right in addition to aligning the values to the left. So I ended up with something like this:

var memememe = {
          name: 'Stoyan',
   family_name: 'Stefanov',
          blog: 'http://www.phpied.com',
    kids_count: 2,
   books_count: 3,
    occupation: 'programmer'
}

Fancy, eh? I liked the way it looks. But then I thought that when writing maintainable code, anything fancy suggests uncommon, uncommon suggests that other team members won't be using it, so it means breaking the rule #1 of writing maintainable code: be predictable. (this also happens to be rule #1 of other common activities, such as driving on the highway and designing usable web sites)

This type of formatting is also not easy to type in an editor, so it will require a little more effort. Those two drawbacks are enough, I believe, to dismiss this idea. But I can't help myself liking the way the code looks. Here's a piece of PHP, which looks even better than javascript, because even more characters are centered.

<?php
$memememe = array(
          'name' => 'Stoyan',
   'family_name' => 'Stefanov',
          'blog' => 'http://www.phpied.com',
    'kids_count' => 2,
   'books_count' => 3,
    'occupation' => 'programmer'
);
?>

Ain't that cool?

This post is a demo of what the imagefilter() PHP function can do for you.

The Original

imagefilter() called with different filter constants

Filter: IMG_FILTER_BRIGHTNESS
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_BRIGHTNESS, 5);
imagepng($image, 'img_filter_brightness_5.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_BRIGHTNESS
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_BRIGHTNESS, 50);
imagepng($image, 'img_filter_brightness_50.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_BRIGHTNESS
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_BRIGHTNESS, 100);
imagepng($image, 'img_filter_brightness_100.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_GRAYSCALE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagepng($image, 'img_filter_grayscale.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_CONTRAST
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_CONTRAST, 5);
imagepng($image, 'img_filter_contrast_5.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_CONTRAST
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_CONTRAST, -40);
imagepng($image, 'img_filter_contrast_-40.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_CONTRAST
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_CONTRAST, 50);
imagepng($image, 'img_filter_contrast_50.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_COLORIZE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_COLORIZE, 100, 0, 0);
imagepng($image, 'img_filter_colorize_100_0_0.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_COLORIZE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_COLORIZE, 0, 100, 0);
imagepng($image, 'img_filter_colorize_0_100_0.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_COLORIZE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_COLORIZE, 0, 0, 100);
imagepng($image, 'img_filter_colorize_0_0_100.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_COLORIZE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_COLORIZE, 100, 100, -100);
imagepng($image, 'img_filter_colorize_100_100_-100.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_COLORIZE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_COLORIZE, 50, -50, 50);
imagepng($image, 'img_filter_colorize_50_-50_50.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_EDGEDETECT
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_EDGEDETECT);
imagepng($image, 'img_filter_edgedetect.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_EMBOSS
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_EMBOSS);
imagepng($image, 'img_filter_emboss.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_GAUSSIAN_BLUR
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GAUSSIAN_BLUR);
imagepng($image, 'img_filter_gaussian_blur.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_SELECTIVE_BLUR
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_SELECTIVE_BLUR);
imagepng($image, 'img_filter_selective_blur.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_MEAN_REMOVAL
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_MEAN_REMOVAL);
imagepng($image, 'img_filter_mean_removal.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_SMOOTH
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_SMOOTH, 5);
imagepng($image, 'img_filter_smooth_5.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_SMOOTH
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_SMOOTH, 50);
imagepng($image, 'img_filter_smooth_50.png');
imagedestroy($image);
?>

Filter: IMG_FILTER_NEGATE
Code to reproduce:
<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_NEGATE);
imagepng($image, 'img_filter_negate.png');
imagedestroy($image);
?>

A lazy way to do sepia

In order to do sepia, first you do grayscale, then colorize. Here are some experiments:


<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagefilter($image, IMG_FILTER_COLORIZE, 100, 50, 0);
imagepng($image, 'sepia_100_50_0.png');
imagedestroy($image);
?>


<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagefilter($image, IMG_FILTER_COLORIZE, 100, 70, 50);
imagepng($image, 'sepia_100_70_50.png');
imagedestroy($image);
?>


<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagefilter($image, IMG_FILTER_COLORIZE, 90, 60, 30);
imagepng($image, 'sepia_90_60_30.png');
imagedestroy($image);
?>


<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagefilter($image, IMG_FILTER_COLORIZE, 60, 60, 0);
imagepng($image, 'sepia_60_60_0.png');
imagedestroy($image);
?>


<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagefilter($image, IMG_FILTER_COLORIZE, 90, 90, 0);
imagepng($image, 'sepia_90_90_0.png');
imagedestroy($image);
?>


<?php
$image = imagecreatefrompng('nathalie.png');
imagefilter($image, IMG_FILTER_GRAYSCALE);
imagefilter($image, IMG_FILTER_COLORIZE, 45, 45, 0);
imagepng($image, 'sepia_45_45_0.png');
imagedestroy($image);
?>

You can read about the right way to do sepia in Wikipedia, but I'd say that the fakes above look pretty good too.
You can try with different values for R, G and B, but hear this - the thing about sepia is that it's brownish-yellow.
Brown is something that has more red, little blue and the green exactly in between the red and the blue. So brown examples would be (200, 100, 0) or (150, 100, 50).
Yellow on the other hand is equal red and green and no blue, like (255, 255, 0). So if you want more brownish sepia, use the first pattern when calling the colorize filter.

About part one

Part one of the image fun is here, it contains code that more or less does the same things, but pixel by pixel, which is very slow, but also works in PHP4.
At the time of writing part one, imagefilter() funtion was probaly only in cvs, not part of the official PHP. imagefilter() is PHP5-only.

Aloha, I'm back from a family vacation in Maui, HI, feeling rejuvenated after having fun on some nice beaches with crystal water, seen an ex-volcano, sunsets, etc.

An email from PHP Quebec was in my inbox saying I'll be speaking at the 2008 PHP Conference in Montreal. Isn't that great?! I'll have a chance to (have some poutine) meet my friends in Montreal, enjoy (the poutine!) the snow I'm sure I'll be missing this year in LA. If you're in Montreal (do try poutine!), the conference is in March and features quite an impressive lineup of PHP speakers.

I had about 200 entries to go over in my RSS reader. I don't read a lot of blogs (not up-to-date list here) but those that I do are really interesting. That explains why after 2-3 hours of reading, I have only 150 out of 200 posts left to read. Anyway, here's a jewel I came across today - theonion.com (via)

Another one from the "this is not a syntax error" department.

The front-end developer is a strange beast who has to jiggle to and fro and code in several languages literally at the same time - javascript, html, css, php or some other server side language, some SQL dialect... No wonder that sometimes we make silly mistakes like:

var $myarray;
var array = array();
$myarray = [];
foreach(var i in myarray)

Last night I just did a silly mistake like this. In JavaScript I used the PHP way of concatenating strings. Something like:

var user = 'Stoyan';
alert('hello ' . user);

This is obviously wrong, but the thing is that it's not a syntax error as one might expect. It alerts "undefined". Why is that?

Well, 'hello' is a string object. You can call methods and properties on it, like:

>>> 'hello'.toUpperCase()
"HELLO"
>>> 'hello'.length
5

And spaces don't matter...

>>> 'hello'     .   length
5
>>> 'hello'  . toUpperCase()
"HELLO"

So 'hello' . user is an attempt to access the "user" property of the string object 'hello'. This property doesn't exist, hence the "undefined" result.

Doing the opposite (using JavaScript-type concatenation in PHP) is also not an error:

$user = 'Stoyan';
echo 'Hello ' + $user; // prints 0

As bloged before, my publisher organizes a "Best CMS" award thingie and I'm one of the judges in the "Best PHP CMS" category. It's time now to sit on my behind and judge, as scary as it sounds. I have to pick three from the five finalists in the PHP category in any order, so that makes it easier. It could also mean I just pick two I don't like and call it a day. But I want to be more responsible than that and actually experience the pain and the pleasure of building a web site with each CMS. Installing, customizing, add/edit/publishing content, upgrading ... the whole thing.

So I picked 5 domains of mine that already have something published and decided to convert them to one of the CMS's. I picked which CMS will be used for each domain by ordering the domains and the CMS's alphabetically, I think this is as random as any other way of doing it. Here's the list in the format: domain-cms-description.

• bebetata.com - CMS Made Simple - will have photos of my kids, content in Bulgarian, "bebetata" means "the babies"
• csssprites.com - Drupal - currently tool for creating CSS sprites, will expand to have articles, tips, etc.
• hiliteme.com - e107 - tool for highlighting code, will add articles, different methods to highlight, etc.
• jspatterns.com - Joomla! - best/worst practices when it comes to coding javascript
• ragtimebg.com - PHP Fusion - this will be a site for my mother-in-law's business, in Bulgarian. "About us", "contact", that kind of stuff. Also articles on how to take care of your tires. The current version is at ragtime.hit.bg (don't laugh, this site is ooold, featuring client-side inclusion of header and footer, using document.write, fun stuff)

As you can see, different sites with different requirements, so hopefully I'll think of interesting scenarios to try and achieve with each CMS. Any requirement I implement in one CMS, I'll try in all others, so that things are as fair as possible.

I posted initial musings on the "best CMS" problem some time ago in this posting over at opensourcecommunity.org, where the charming Amy Stephen is a frequent contributor.

Wish me luck to have this initiative more than just a nice "wannado".

Simplified, but still...

<?php
if (!function_exists('file_put_contents')) {
    function file_put_contents($filename, $data) {
        $f = @fopen($filename, 'w');
        if (!$f) {
            return false;
        } else {
            $bytes = fwrite($f, $data);
            fclose($f);
            return $bytes;
        }
    }
}
?>

So there is this group of local LA web developers that meet every month or so to meet and discuss what's up. More about/join the group here.

This month Yahoo will be hosting the meetup in the Santa Monica office (my workplace), it's actually tomorrow, so if you're in LA, don't miss the opportunity for beer, pizza and meeting fellow web devs. RSVP here.

On Yahoo's side, Jim Bumgardner, a.k.a. krazydad will be demoing the Facebook app he did that allows you to find music videos and discover artists similar to the ones you like. The app, Jim talking about it, Yahoo Developers Network posting.

Sounds like it would be fun, and also a chance for a local web dev to see what Yahoo's office looks like, meet some of the people that work here, and in a way to try-before-you-apply

Nominate your favorite open-source CMS before August 31st. (Yours truly is one of the judges in the PHP category.)

Here are some convenient tools I've added to my TextPad editor, hope you'll like 'em.

TextPad tools

Stuff can easily be added to TextPad's Tools menu, like I did, shown on the screenshot.

In order to do so, you go Configure -> Preferences. Then select Tools on the tree to the left, then Add. You can add a DOS command, an application or a help file (.hlp or .chm)

The first three tools on the picture above come out-of-the-box, the other 4 I've added myself. Let me show you what I did.

Tool #1 - PHP lint (a.k.a. syntax check)

So I'm editing a PHP file and I want to syntax check it from the editor. Good. PHP on the command line comes with the -l option (this is lowercase L) which does just that. For example if you run this from your command prompt, it will check the file test.php for syntax errors:
C:\php> php -l test.php

So for tool #1 I just did - Configure-Preferences-Tools-Add-DOS command, then typed:
php –l $File

In Textpad apparently $File refers to the current file being edited. So now I can edit a file, press CTRL+4 and syntax check the file. Neat.

Tool #2 - PHP help

This is exactly the same idea as the previous tool. I use PHP command line option --rf which gives you help information. For example try getting help with the str_replace() function:

C:\php>php --rf str_replace

The result is

Function [ <internal> public function str_replace ] {

  - Parameters [4] {
    Parameter #0 [ <required> $search ]
    Parameter #1 [ <required> $replace ]
    Parameter #2 [ <required> $subject ]
    Parameter #3 [ <optional> &$replace_count ]
  }
}

Adding this functionality to textpad is very similar to tool #1, only this time the command is:

php --rf $SelWord

$SelWord is the currently selected word in textpad (just placing the cursor somewhere in the word is enough)

Tool #3 - PHP Manual

Sometimes the help above is not enough and you want to hit the manual on php.net. Here's the next tool. You go:
Configure-Preferences-Tools-Add-Program and you find your firefox.exe, like
C:\Program Files\Mozilla Firefox\firefox.exe

Now, in order to edit a tool you created in TextPad, you need to expand the Tools node of the Preferences tree and click the tool you need, as shown on the screenshot:

In this screen, you need to type this in the Parameters field:
http://php.net/$SelWord

Tool #4 - JS Lint

JSLint is a tool for checking JavaScript code, it also can be run on the command line in Windows, using cscript. So if your jslint.js is in C:\, you can have tool #4 another DOS command:

cscript C:\jslint.js <$File

Hope you like it

Or maybe add these simple tools to your text editor of choice.

Last thing

One little thing I didn't mention - it's a bit of a challenge to figure out how to rename a tool once created. Basically on the list of tools (next to the Add button), just click, right click, double-click or simultaneously click left and right mouse buttons. One of these will work eventually

Let's go ahead and optimize our phpBB installation for front-end performance. I'll follow Yahoo's 14 optimization rules, but only implement the ones that apply for phpBB. During this short workshop there will be no changes to the phpBB code, we'll create a new template instead, so that in case something bad happens, your board will continue to work normally. As an example, I'll use the bgcanada.com/phpBB2, the board I volunteer to administrate.

The plan

1. creating two subdomains to host assets - images and css, maximizing parallel downloads (also following rule #9)
2. creating a new template (theme) based on the default subSilver template
3. moving CSS to an external file (rule #8), merging the two css files (rule #1)
4. copying images and css to the new subdomains
5. making sure css is served gzipped (rule #4) and also making sure php pages are served gzipped)
6. turning ETags off (rule #13)
7. setting the Expires header (rule #3)
There will be no explanations on the reasoning why these rules exists, but only how to implement the applicable ones in phpBB. It's a good idea though to go through the links above and read the detailed description of the rules. Maybe you'll find something that can be done in addition to the plan above. The suggested implementations were done and tested on a normal $60/year shared host, working around the limitations of such hosting. I'll speculate that at least 90% of the phpBB installations out there use shared host so I hope my implementation will be relevant to your phpBB install as well.

New subdomains

Typically, shared hosts allow subdomains and have their admin interface for doing so. In case your host is an exception, alternatively you can buy one or two extra domains to use for the same purpose - storing page assets.

So in my case, for the domain bgcanada.com I create two sub-domains - i1.bgcanada.com and i2.bgcanada.com (i as in image). Now the question would be how to divide assets between the two domains. I decided that more or less half of the images are multilingual (they don't contain text) so these go to i2. i1 will have all the rest - translatable images found in subSilver/images/lang_english, smilies and the stylesheet.

creating a new template

Let's go ahead and create a new template (theme), based on the default subSilver template. I'll call mine "sso" as in "subSilver optimized" (or the longer mirror-like version "ssoss" as in "stoyan stefanov, oh, so smart" )

For this purpose, just take the contents of path/to/phpbb/templates/subSilver and copy it under the name "sso", so you'll have /templates/sso, an exact subSilver copy.

Now go ahead and modify templates/sso/subSilver.cfg, the theme configuration. First rename it to sso.cfg. Then at the top of the document, replace the line:

$current_template_images = $current_template_path . "/images";

with

//$current_template_images = $current_template_path . "/images";
$i1 = "http://i1.bgcanada.com/sso"; // language and smilies
$i2 = "http://i2.bgcanada.com/sso"; // the rest

use your domain, of course.

Then do a search/replace. All occurrences of:

$current_template_images/{LANG}/

should become

$i1/{LANG}/

And all occurrences of

$current_template_images/

become

$i2/

At the end of the file, just before ?> add a new line:

$board_config['smilies_path'] = 'http://i1.bgcanada.com/smilies';

This will overwrite the path to the smilies you set in the admin interface. This is optional, you can achieve the same by using the admin panel, but we said we wanted to have the board unaffected by the changes.

Now open templates/sso/theme_info.cfg and replace all occurrences of "subSilver" with "sso".

Now the bad news is that some of the template files (.tpl) still contain relative paths to images, we need to make these absolute and pointing to the subdomians. Since these paths are hardcoded in the templates we're sure that they are language independent, so they'll all go to the i2 subdomain. If you have a good text editor that can search/replace in multiple files, go ahead. Alternatively, use the php script I came up with. Download it, copy it to your /templates/sso folder, rename to replace.php and use it like:
C:\path\to\phpbb\templates\sso> php replace.php
It will report what it replaced.
It only searches for templates/subSilver/images and replaces with http://i2.bgcanada.com/sso

Yep, almost done with the template, one last step - the css.

Moving CSS to an external file, merging

In the default subSilver there are style definitions in overall_header.tpl. Remove them, the whole thing between the <style> tags and replace with:

<link rel="stylesheet" href="http://i1.bgcanada.com/sso.css" type="text/css">

Now rename subSilver.css to sso.css. Copy the contents of formIE.css and append it to the end of sso.css. Optionally, you can walk through the new file and strip all comments and white space. Or use my stripped version.

Note that as a side effect, the font of the board will look somewhat different, because the definitions in subSilver.css are not exactly the same as those in the overall_header.tpl. It's not a big difference, but if it's important to you, just ignore the original subSilver.css and create sso.css copying the styles from overall_header.tpl and formIE.css.

We're done with the files, the rest is sysadmin stuff.

copying files to the new subdomains

That's easy, just take everything from templates/sso/images (leave the lang_english or any other language folders) and copy to http://i2.bgcanada.com/sso

Than take all lang_* folders and copy to http://i1.bgcanada.com/sso, so you'll have http://i1.bgcanada.com/sso/lang_english/

Now copy all smilies from phpbbroot/images/smilies to http://i1.bgcanada.com/smilies/

Now take the sso.css you created and copy to http://i1.bgcanada.com/sso.css

Last, take the whole sso directory and copy to the main domain - http://www.bgcanada.com/phpBB2/templates/ so that it's in the same folder next to subSilver.

Login to the admin panel and activate the new theme as usual. Login to your account and change your theme preference to sso. You still want to test before making it a default theme for everyone.

At this point you should be able to browse your forum with the new theme and everything should look like as if you were using subSilver.

Serving gzipped content

The rule is that all served files should be gzipped, with exception for images, because gifs, jpgs, pngs are already compressed.

To serve the normal html (php) pages gzipped, just use the built-in phpBB feature, log on to the admin panel and enable gzip compression.

To serve sso.css gzipped, ideally you should only create an .htaccess file and have Apache do it for you (more info). Unfortunately my host won't allow it, so I took the alternative path - have PHP gzip and serve the css file. To do so I created an .htaccess file http://i1.bgcanada.com/.htaccess and put in it:

AddHandler application/x-httpd-php .css

This affects all CSS files (but we have only one) and makes them php scripts. If your host allows you to use php_value in .htaccess, you can do the rest of the job by only using .htaccess. Otherwise create a http://i1.bgcanada.com/php.ini file and put in it:

[PHP]
default_mimetype = "text/css"
zlib.output_compression = On
zlib.output_compression_level = 6
expose_php = Off
auto_prepend_file = "pre.php"

The first line makes php send text/css header instead of the default text/html. Some browsers won't like CSS files served with text/html header. The second line enables compression and the next line sets the compression level (could be up to 9). 4th line is absolutely optional, just removes an extra header that PHP sends. The last line sets that all served php files should include the file pre.php as if you used include "pre.php" inside every PHP script. This is actually used later for the Expires header.

turning ETags off

That's super easy. Just add .htaccess rules in both i1 and i2 to say:
FileETag none

Expires header

To set the expires header, add these lines to .htaccess on both i1 and i2

ExpiresActive On
ExpiresDefault "access plus 2 years"

This makes all files - images and CSS - on i1 and i2 expire in 2 years, if that's too much/not enough, feel free to change.

If it doesn't work for you (it didn't for me, because of the host), you can go the php auto_prepend route described above and add in the pre.php file
header('Expires: ' .gmdate("D, d M Y H:i:s",time() + (60 * 60)) . ' GMT');
Feel free to set 60 * 60 to whatever you think makes sense for you. Note that this will only affect the CSS file, images will be served "normally". You can also have PHP serve all the images, like we did for CSS, but I think it's probably too much.

Sysadmin summary

There was a lot of if-then above so let me summarize what worked for me, but try your other options first to see how "liberal" your host is in order to do a better job than me.

http://i1.bgcanada.com/.htaccess

AddHandler application/x-httpd-php .css
FileETag none

http://i1.bgcanada.com/php.ini

[PHP]
default_mimetype = "text/css"
zlib.output_compression = On
zlib.output_compression_level = 6
expose_php = Off
auto_prepend_file = "pre.php"

http://i1.bgcanada.com/pre.php

<?php
header('Expires: ' .gmdate("D, d M Y H:i:s",time() + (60 * 60)) . ' GMT');
?>

Done!

We're done! Did it take more than an hour? Hope not, although with these computers and stuff, everything takes more time than expected.

Do you see anything missing? Or something that can be improved? Or something didn't work for you? Please post a comment. The whole posting is a bit fast-paced and written in a rush (I really need to go to bed), so if there's something unclear please ask.

So I launched this little tool csssprites.com that allows you to upload images and create one CSS sprite image, plus it gives the background-position CSS definitions to use in order to show parts of the sprite. People have been trying it out, but unfortunately sometimes uploading 20 megs of images to create a sprite, which is not the point of the css sprites technique. Anyway as a result I exceeded the disk quota my host gives me and since the site is hosted on the same server as this blog, the blog stopped working. Hence the publishing diet.

Initially I blamed WordPress because it started acting strangely, asking me to update my database, saying that I don't have admin privileges, then not loading the CSS files and finally just stopped working even on the front end. I said oh well, I need to upgrade it anyway, so let's do it now. Just trying to FTP a single file got me the message that I can't copy so I finally figured out the real case - the exceeded disk space.

It's all good now, I just deleted all CSS sprite images that were generated, I was planning to do a cron job do delete the ones older than a day or two anyway, but never got around doing it. I should just check and warn the cssspritres.com users not to upload huge images, because this is not how CSS sprites were designed to work anyway.

Long story, short message. I'm off the publishing diet now.

Meanwhile I wrote an article for the International PHP Magazine, it's an intro to unit tetsing with PHPT, called "PHPT - Unit testing for the rest of us". Nice, eh? Just got an email today that the new IPM issue is out the door, you can check the TOC here. I wanted to further experiment with PHPT and was thinking of writing this test generation tool. Say you have a bunch of classes, you run the tool and it generates PHPT test stubs, based on the classes and methods in finds. Then you tweak the generated stubs here and there to implement the actual tests. PHPUnit has this feature, so why not PHPT as well. We'll see if I'll find the time.

On a different technology, I was playing around implementing the decorator pattern in Javascript, will post about it later (sneak peek).

On a different subject, just added a few very simple tools to my favorite Textpad, I found them helpful for PHP development, will post about them later.

On a yet another subject a few days ago I finished a draft outline for my new book-to-be and we started discussing with the editor.

On a totally unrelated subject, I did a new phpBB theme (copy of the default subSilver) following as many of the Yahoo front end performance rules as I found applicable. Naturally, I'll post about it later.

Otherwise life has been good. I moved with my family to LA to start working for this company called Yahoo!. Work is great, LA was bit of a surprise and not very welcoming, but hey, it's the experience. We had some initial rental issues (we lost quite a bunch of money double and some point triple renting), then there was the stress of the whole move, having to start everything over again, driving licenses, shocking 20% APR rates from Toyota, credit cards refusals and stuff (the only thing that I still use here from Canada is the Costco card!). Yahoo did help a lot during the moving process, can't imagine what would have been without all the little and not so little perks I got during the relocation. So anyway, after all that initial shock, the family is starting to settle. The kids just loooove Disneyland, we ended up getting anual passes for California residents, so we'll be seeing it a lot. Also the beach is quite nice, not the cleanest mind you, but it's probably because we're new don't know where to go, we just hit the closest to us, in Venice. By the way, Venice is amazingly similar to some little Bulgarian towns on the Black Sea. In general LA is quite expensive, especially the Santa Monica area, where the office is, but I wanted to be close to the family in those times of change, so we ended up renting a place only 5 miles from the office (still getting used to those miles and pounds). I proudly bike to work now, doing my share in saving the environment. Half an hour in each direction, it's a nice excersise. Talking about biking, here's some biking-to-work wisdom for you:

Tree branches are hanging lower than they appear.

also

Just when you thought you learned how to bike without using your hands and to light a cigarette meanwhile... you didn't.

Here's my last weekend's project - a web-based tool to generate images for CSS sprites: http://www.csssprites.com. Cool domain name, eh? I couldn't believe it was not taken.

CSS Spr...what?

This is a simple technique used for page load performance purposes. Since HTTP requests are the most expensive thing you can do in regards to front-end performance, you strive for making as little requests as possible. So instead of having the browser download 4 rounded corner images for example, you create one image that has all four. Then you use CSS' background-position to only show the part of the image you want. More on the subject in this ALA article

How does the tool work

You upload as many images as you want and the tool generates a mosaic of all images, gives you the result as PNG and gives you the coordinates you need to use in the background-position declaration. The tool also gives you an html page as an example, so you can save both the PNG and the html page for reference.

Image size

If you properly optimize the big image, you might actually have smaller size than all the individual images combined. In my tool, the PNG image generated is not optimized at all, I leave this to you to use PNGOUT or any other tool you know. Also you can convert the PNG into GIF if that's better for your purposes.

Implementation - PHP

The PHP code is fairly simple. The actual spriting (is that a word?) class takes a list of images and calls getimagesize() on each one to get the dimensions. The image with the biggest height is used as distance between images. The rest is just composing the imagemagick command that will to the work. Here's the important method:

<?php
function combine() {
    if ($this->distance === false) {
        $distance = $this->_biggest;
    } else {
        $distance = (int)$this->distance;
    }

    if ($this->output_dir === false) {
        $output_dir = $this->_dir;
    } else {
        $output_dir = $this->output_dir;
    }

    $half = ceil($distance / 2);

    $coord = array();
    $y = 0;

    foreach ($this->images as $i=>$data) {
        $this->images[$i]['x'] = $half;
        $this->images[$i]['y'] = $half + $y;
        $coord[] = '-page +0+' . $y . ' ' . $i;
        $y += $data[1] + $distance;
    }

    $cmd = 'convert ' . implode(' ', $coord)
         . ' -background none -mosaic -bordercolor none -border '
         . $half . 'x' . $half
         . ' ' . $output_dir . '/result.' . $this->output_format;
    system($cmd, $ret);

    return $ret === 0;

}
?>

Implementation - JS

In the spirit of web2 I couldn't afford a complete page reload although it would've been much simpler. I just had to get fancy. YUI to the rescue. On page load I set up the form for async request, using YAHOO.util.Connection. In case of file uploads YUI generates an iframe behind the scenes and uploads to the iframe. Then it takes whatever is in the body on the iframe and gives it to you instead of the XMLHttpRequest's responseText property.

So the files are uploaded to upload.php which calls the class that has the method mentioned above then loops through the $images property of the said class and writes the example html file as well as prints out a JSON string with the same image information.

YUI's Connection calls my callback function and I get the invaluable responseText. Parsing the JSON with the json.js, I get a JS object. Looping through it and DOM-generating a table of results is the semi-last step. The last is (we're fancy, remember?) to yellow-fade the background color of the result, using YAHOO.util.Animation.

BTW, I got fancy once again and combined and minified json.js with my JS file, so that there is one less request and a side effect impossible to read. The unminified version of the JS that does all the work is here for reference.

Comments

I hope this tool cane be useful for quickly generating those sprites, if only for prototyping purposes. Any comments, requests, bug reports are all very welcome.

And how do you like the version of the tool? Anyone n00b can do "beta", it takes a true h@x0r (or something) to do a better job

Ah, yeah, and the page badly needs a stylesheet, do you want to help?

I've been selected as a judge in this year's Open Source CMS Award, organized by Packt Publishing. I'll be voting for three out of 5 PHP CMS projects where those 5 are selected by votes from the site visitors. Join me in a discussion I started at opensourcecommunity.org "What do you think makes a good CMS?"

Nice title, eh?

OK, so all of a sudden theweathernetwork.com buttons I was using to show the weather in Sofia, Bulgaria and selected Canadian cities on the community site bgcanada.com, stopped working. Reason: unknown. So it was time for a change, since those buttons were generated by some javascripts, hosted by theweathernetwork, which is kind of a web 1.0 way of sharing content. In the days of APIs and stuff, this is a shame.

The first substitute that came to mind to check were the Yahoo APIs and feeds and, no surprise, they do offer weather feeds. All you need is the code of the city you're interested in (or zip code for the States) and you're good to go. I also wanted the temperatures to be displayed in Celsius, and there was indeed an option to set this. The feed URL for Montreal for example looks like:

http://weather.yahooapis.com/forecastrss?p=CAXX0301&u=c

With a little searching on the real Yahoo weather site, I was able to figure out the codes of the cities I'm interested in. From there it was a breeze.

Here's the script that takes an array of cities and produces a single HTML page with the weather information. It's using simplexml_load_file(), which makes things so simple, it's scary.

<?php
// array of cities we're interested in
// the codes are taken from weather.yahoo.com URLs
// by searching for the city
$cities = array(
    'Sofia'     => 'BUXX0005',
    'Montreal'  => 'CAXX0301',
    'Toronto'   => 'CAXX0504',
    'Vancouver' => 'CAXX0518',
    'Ottawa'    => 'CAXX0343',
);

// general purpose feed URL with placeholder for city code
$feed = 'http://weather.yahooapis.com/forecastrss?p=%s&u=c';

// loops cities
foreach ($cities AS $name => $code) {

    // load XML from the real feed URL
    $url = sprintf($feed, $code);
    $res = @simplexml_load_file($url);

    // on success, spit out city name and weather data
    if ($res) {
        $data = $res->channel->item->description;
        echo '<h2>', $name, '</h2>', $data;
    }
}
?>

If you use PEAR::MDB2, you can set a custom debug handler and collect all the queries you execute for debugging and performance tunning purposes, as shown before. But what if you're using PEAR::DB? Well, since PEAR::DB doesn't allow you such a functionality out of the box, you can hack it a bit to get similar results.

Simple app

Let's say you have a simple app:

<?php
require_once 'DB.php';

$dsn = 'mysql://root@localhost/test';
$db =& DB::connect($dsn);
$db->setFetchMode(DB_FETCHMODE_ASSOC);

$sql = 'SELECT * FROM zipcodes';
$result = $db->getAll($sql);
$result = $db->getOne($sql);
$result = $db->getCol($sql);
$result = $db->getAll($sql);
$sql = 'SELECT zipcode FROM zipcodes';
$result = $db->getAll($sql);
$result = $db->getAll($sql);
$sql = 'SELECT CONCAT(zipcode, " - ", city) FROM zipcodes';
$result = $db->getAll($sql);
?>

Of course, this is an oversimplified example, usually you have more included files, class libraries and such, and it's not difficult to lose track of the database work as your app grows in complexity and size.

Now let's debug this app to see what type of database work it does.

Hacking PEAR::DB

In my case, I'm using MySQL, so I need to find the DB/mysql.php file in my PEAR directory. I open that file and find the simpleQuery() method. That's where all queries and up, sooner or later. I find this piece of code:

<?php
if (!$this->options['result_buffering']) {
    $result = @mysql_unbuffered_query($query, $this->connection);
} else {
    $result = @mysql_query($query, $this->connection);
}
?>

Then I hack this piece of code, adidng some lines before and after it. The result:

<?php
// start
$start_time = array_sum(explode(' ',microtime()));
// end

if (!$this->options['result_buffering']) {
    $result = @mysql_unbuffered_query($query, $this->connection);
} else {
    $result = @mysql_query($query, $this->connection);
}

// start
$query_took = array_sum(explode(' ',microtime())) - $start_time;
@$GLOBALS['global_query_counter']++;
@$GLOBALS['all_the_queries'][$GLOBALS['global_query_counter'] . ' - ' . $query] = $query_took;
//end
?>

Now as my app's pages are executed, I'll collect invaluable DB information.

Reporting

Let's see what we've collected.

You can add different types of reports in the footer of your application, or better yet, you can register a shutdown function to do the same. Here are some reporting ideas:

<?php
// report 1.
echo "<pre>All the queries, by the order they are executed:\\n";
print_r($GLOBALS['all_the_queries']);
echo '</pre>';

// report 2.
echo "<pre>All the queries, ordered by the time they took, descending:\\n";
arsort($GLOBALS['all_the_queries']);
print_r($GLOBALS['all_the_queries']);
echo '</pre>';

// report 3.
$sum = 0;
foreach ($GLOBALS['all_the_queries'] AS $t) {
    $sum += $t;
}
echo '<pre>';
echo 'Total number of queries:   ' . $GLOBALS['global_query_counter'] . "\\n";
echo 'Total time spend querying: ' . $sum;
echo '</pre>';

// report 4.
$distinct = array();
foreach ($GLOBALS['all_the_queries'] AS $q=>$t) {
    $parts = explode(' - ', $q);
    unset($parts[0]);
    $query = implode(' - ', $parts);
    @$distinct[$query]++;
}
echo "<pre>How many duplications:\\n";
arsort($distinct);
print_r($distinct);
echo '</pre>';
?>

Report results

Let's see what these reports gives us.

All the queries, by the order they are executed:
Array
(
    [1 - SELECT * FROM zipcodes] => 0.00626707077026
    [2 - SELECT * FROM zipcodes] => 0.00730204582214
    [3 - SELECT * FROM zipcodes] => 0.00796985626221
    [4 - SELECT * FROM zipcodes] => 0.00654602050781
    [5 - SELECT zipcode FROM zipcodes] => 0.0058650970459
    [6 - SELECT zipcode FROM zipcodes] => 0.0239379405975
    [7 - SELECT CONCAT(zipcode, " - ", city) FROM zipcodes] => 0.00581502914429
)

All the queries, ordered by the time they took, descending:
Array
(
    [6 - SELECT zipcode FROM zipcodes] => 0.0239379405975
    [3 - SELECT * FROM zipcodes] => 0.00796985626221
    [2 - SELECT * FROM zipcodes] => 0.00730204582214
    [4 - SELECT * FROM zipcodes] => 0.00654602050781
    [1 - SELECT * FROM zipcodes] => 0.00626707077026
    [5 - SELECT zipcode FROM zipcodes] => 0.0058650970459
    [7 - SELECT CONCAT(zipcode, " - ", city) FROM zipcodes] => 0.00581502914429
)

Total number of queries:   7
Total time spend querying: 0.0637030601501

How many duplications:
Array
(
    [SELECT * FROM zipcodes] => 4
    [SELECT zipcode FROM zipcodes] => 2
    [SELECT CONCAT(zipcode, " - ", city) FROM zipcodes] => 1
)

Thanks for reading!

Any comments or suggestions are very welcome!

What could possibly be better for a writer's ego other than being read and being praised? Hmm...

So I wanted to have a page that shows the books I've written, together with their Amazon sales rank and the average customer rating and number of reviews. It's really easy. I took one example out of the PEAR book and slightly modified it.

The result is here.

Implementation at a glance

• Get an Amazon Web Services (AWS) subscription id
• Get a copy of PEAR::Services_Amazon package
• Make a request
• Display the response

When making a request, you need to say what type of request it is and what type of response you want. It's documented here. For the type of request, look under "API reference -> Operations" and for the response type, look under "API reference -> Response Groups"

The code

<?php

// include the PEAR package
require_once 'Services/AmazonECS4.php';

// Your AWS subscription id
$subscriptionId = '1WQDAES5PQ**********';

// create a new client by supplying
// subscription id
$amazon  = new Services_AmazonECS4($subscriptionId);
$amazon->setLocale('US');

// output options
// what do you need returned?
$options = array();
$options['ResponseGroup'] = 'SalesRank,ItemAttributes,Reviews';

// for which books
// comma-delimited list of ISBNs
$items = '1904811795,1904811914,1904811132';

// do the request
$result = $amazon->ItemLookup($items, $options);

// check for errors
if (PEAR::isError($result)) {
    print "An error occured<br/>";
    print $result->getMessage() . "<br/>";
    exit();
}

// some spaghetti to display HTML response
echo '<ul>';
foreach ($result['Item'] as $book) { // loop the books
    // URL
    echo '<li><a href="'. $book['DetailPageURL'] .'">';
    // book title
    echo $book['ItemAttributes']['Title'], '</a><br />';
    // authors, comma-delimited
    echo implode(', ',$book['ItemAttributes']['Author']);
    // sales rank
    echo '<br />Sales rank: ', $book['SalesRank'];
    // average rating
    if (!empty($book['CustomerReviews'])) {
        echo '<br />Rating: ';
        echo $book['CustomerReviews']['AverageRating'];
        echo ', based on ';
        echo $book['CustomerReviews']['TotalReviews'], ' reviews';

    }
    echo '</li>';
}
echo '</ul>';
?>

<a
  href="#"
  onclick="javascript:document.getElementById('response').style.display='block';"
  >Show complete response</a>
<pre id="response" style="display: none">
<?php print_r($result); ?>
</pre>

Today I saw a post at digg.com on image resizing with PHP and there was quite a discussion. Let me share the laziest way (that I know of) how to do it - PEAR::Image_Transform is all it takes. Here goes:

<?php
require_once 'Image/Transform.php';
$i =& Image_Transform::factory('');

$i->load('test.jpg');
$i->fit(100,100);
$i->save('resized.png', 'png');
?>

In addition, the Image_Transform library offers diffferent ways (to skin the old cat) to resize an image - by given pixel value, only on the X axis, on Y, scalling in percentage and so on. And, of course, the library can do much more than resizing, as you can see in the API docs.

It supports all kinds of image manipulation extensions - GD, GD1, ImageMagick, NetPBM, Imlib... If you want to use a specific one, you set as a parameter to the factory() method. In the example above I passed an empty string, so it will try to figure out what's available in my PHP setup and use it, trying Imagick2 first, then GD, then Imlib.

You have setOption() and setOptions() methods if you want to play around with the image quality and those sort of things.