This function might come in handy when loading settings from a configuration file.

/**
 * Sets a field of a multi-dimensional array by specifying the key in a
 * flat string format
 *
 * Usage example:
 *
 *   $demo = array();
 *   arraySetByFlatKey($demo, 'this.is.a.test', 'Hello World!');
 *   arraySetByFlatKey($demo, 'this.is.a.monster', 'Brwaaa!');
 *
 * Sets:
 *
 *   $demo['this']['is']['a']['test'] = 'Hello World!';
 *   $demo['this']['is']['a']['monster'] = 'Brwaaa!';
 *
 * @param array $a Array to set the index of
 * @param string $key Flat key representation
 * @param mixed $value Value to set the index to
 */
function arraySetByFlatKey(array &$a, $key, $value, $delimiter = '.')
{
    $keyParts = explode($delimiter, $key);
    $leaveKey = array_pop($keyParts);

    $parent = &$a;

    foreach ($keyParts as $part) {
        if (!isset($parent[$part])) {
            $parent[$part] = array();
        }

        $parent = &$parent[$part];
    }

    $parent[$leaveKey] = $value;
}

Hint: If no support for varying character lengths is needed (e. g. when not working with UTF-8), the mb_* function calls should be replaced with their non-multibyte pendants. Especially mb_strpos is very inefficient when used in loops.

/**
 * Returns the longest intersection of two strings
 *
 * Usage example:
 *
 *   $a = 'This is a wonderful test string.';
 *   $b = 'This is another wonderful string.';
 *   var_dump(getLongestIntersection($a, $b)); // string(11) " wonderful "
 * 
 * @param string $haystack First string
 * @param string $needle Second string
 * @return string Longest intersection of both strings
 */
function getLongestIntersection($haystack, $needle)
{
    // Length of needle string
    $nLen      = mb_strlen($needle);

    // Starting point (in needle) of longest matching substring
    $maxAnchor = 0;

    // Length of (so far) longest matching substring
    $maxLen    = 0;

    // Starting point (in needle) of current substring to test
    $sAnchor   = 0;

    // Length of current substring to test
    $sLen      = 0;

    // Do checks until either substring anchor runs out of needle string or
    // until there is no room left for a longer match
    while ($sAnchor < $nLen
        && $sAnchor + $sLen <= $nLen
    ) {
        // Increase substring length
        $sLen++;

        if (mb_strpos($haystack,
                      mb_substr($needle, $sAnchor, $sLen)) !== false
        ) {
            /* Substring found. A new match is always the longest match */

            $maxLen    = $sLen;
            $maxAnchor = $sAnchor;
        } else {
            /* Substring not found */

            // Shift anchor one position to the right
            $sAnchor++;

            // Don't bother looking for substrings shorter than current best
            // match. This makes sure that a new match is always the longest
            // match up to this point
            $sLen--;
        }
    }

    return mb_substr($needle, $maxAnchor, $maxLen);
}

This is the first entry of a small advent calendar series featuring PHP snippets. Hopefully one or two of them will be useful to anyone.

Today, we start with a function to pick a random entry from a weighted array.

/**
 * Picks an element from a weighted array
 *
 * @param  array $map "Element to weight factor" mappings (<mixed> => <int>)
 * @return mixed|null Picked element or null if empty array
 */
function pick(array $map)
{
    $sum  = array_sum($map);
    $rand = mt_rand(0, $sum - 1);
    $k    = 0;
    $pick = null;

    foreach ($map as $element => $weight) {
        $k += $weight;
        if ($rand < $k) {
            $pick = $element;
            break;
        }
    }

    return $pick;
}

This example will return „c“ in 60 % of the time, „b“ in 30 % and „a“ in 10 %.

$weights = array(
     'a' => 10,
     'b' => 30,
     'c' => 60,
);

for ($i = 0; $i < 50; $i++) {
    echo pick($weights) . ", ";
}

This example simulates the rolling of two 6-sided dice (2d6).

$twoDice = array(
     '2' => 1,
     '3' => 2,
     '4' => 3,
     '5' => 4,
     '6' => 5,
     '7' => 6,
     '8' => 5,
     '9' => 4,
    '10' => 3,
    '11' => 2,
    '12' => 1
);

$results = array();

for ($i = 0; $i < 100; $i++) {
    $pick =  pick($twoDice);
    $results[$pick] .= '*';
}

ksort($results);

foreach ($results as $pick => $amount) {
    echo $pick . ': ' . $amount . '<br />';
}

There aren't that many articles on Hierarchical Model/View/Controller (HMVC) designs in PHP. This one might be worth a read. (thx Frucht)

A set of vintage calender designs. (via AisleOne)

Peter Gabriel & Hot Chip: Cape Cod Kwassa Kwassa (Vampire Weekend Cover)

Sebastian Bergmann writes that PHP 5.3.99 (which might be released as PHP 5.4) will introduce type hinting for scalar data types (e. g. function f(int $i, string $s) {}).

There is one thing to note: It seems like there are no plans to check or enforce the new type hints in the interpreter, so this feature might be purely syntactical. I am not sure whether this makes a lot of sense to me.

National Geographic was again kind enough to let me choose some of their entries from 2010 for display here on The Big Picture. Collected below are 47 images from the three categories of People, Places and Nature. Captions were written by the individual photographers.

Not surprisingly, most of these photos are great.

Here's a nice collection of ignore templates to be used with a version control system in order to avoid adding temporary files to the repository. The linked templates are written for Git but should be easy to adapt.

Stromae: Alors on danse

<?php

/**
 * Returns all possible permutations of $values containing $n elements using a
 * "draw and place back" algorithm
 *
 * The resulting array will always have pow(count($values), $n) entries.
 *
 * For
 *   $values = array('a', 'b') and $n = 2,
 * the result will contain:
 *   [aa, ab, ba, bb]
 *
 * @param array $values Vector to generate permutations of
 * @param int $n Elements per permutation
 * @return array Possible permutations
 */
function getPermutations(array $values, $n)
{
    $rec = function (array $values, &$ret, $n, array $cur = array()) use (&$rec)
    {
        if ($n > 0) {
            foreach ($values as $v) {
                $newCur = $cur;
                $newCur[] = $v;
                $rec($values, $ret, $n - 1, $newCur);
            }
        } else {
            $ret[] = $cur;
        }
    };

    $ret = array();
    $rec($values, $ret, $n);

    return $ret;
}



$values = range('a', 'd');
$n = 2;

$ret = getPermutations($values, $n);

foreach ($ret as $r) {
    foreach ($r as $d) {
        echo $d;
    }
    echo '<br>';
}

PHPTAL is a template language that might actually be worth using. From the website:

To be short, PHPTAL is a XML/XHTML template library for PHP.

While most web developpers continue to use ASP/JSP/PHP tags as the core language of their templates, the Zope community came with a refreshing idea named TAL. The idea was to move presentation actions inside XHTML attributes instead of using plain tags or elements.

Here's a transcript of the talk „The Design of HTML5“ by Jeremy Keith held at the Fronteers 2010 congress.

I am linking to Jeremy quite a lot lately, but that's okay.

Georg Friedrich Händel: Zadok the Priest

This weekend, the OpenRheinRuhr free software congress takes place at Oberhausen. The talks should be interesting and the admission fee is very low (5 € for two days, 3 € for one day), so there isn't really a reason not to attend, I guess.

There are a lot of Paul Kalkbrenner Livesets on SoundCloud. I can only recommend to listen to some of these if you like minimal techno music.

Home is wherever I'm with you.

Edward Sharpe & the Magnetic Zeros - Home

The current A List Apart issue gets you started with the Git version control system.

"How to hire a programmer when you're not a programmer" (on Signal vs. Noise). Or: What people might be looking for when they are thinking about hiring you.

Lately, Jeremy Keith has shown different examples of responsive web design in his blog. There are at least two other entries: "Responsive refresh" and "Responsive enhancement". I really like the technique.

Dave Winer thinks, "The Social Network" is not a great movie and it's also not very realistic. Roger Ebert likes it quite a lot (four stars out of four). Differing signals.

The Zend Framework's default directory layout assumes that you are able to place all of your library and application code outside of the web server's document root directory. In shared hosting environments, this is often impossible because the document root is the topmost directory you have access to.

Lorenzo Alberton explains how to setup the framework under these conditions.

Here are some Pop/Minimal beats to get things moving:

Chilly Gonzales: Waves (Piano Remake)

Minilogue: Hispaniola

Chilly Gonzales: I Am Europe

AKA AKA ft. Thalstroem: Relajate Remix

Dazzle Camouflage was a camouflage paint scheme used on ships, extensively during World War I. This technique did not conceal the ship but made it difficult for the enemy to estimate its type, size, speed and heading.

Take at look at the images at GraphicHug and Wikipedia.