define('AKISMET_PLUGIN_URL', plugin_dir_url( __FILE__ ));

My WordPress installation is at /usr/share/wordpress, but the Akismet plugin is installed to /var/lib/wordpress/plugins/akismet/ and there is a symlink (symbolic link) inbetween. This means that __FILE__ is /var/lib/wordpress/plugins/akismet/akismet.php but plugin_dir_url does not understand this, and will incorrectly return:

/wp-content/plugins/var/lib/wordpress/plugins/akismet/

This is not a proper URL for my WordPress installation!

I’m still on WordPress 3.0.something, but it seems like this issue is still a problem in newer versions. There are a number of bug reports for this and similar issues:

• 13550
• 16199
• 16953

First of all, what is the Inner-platform effect? It basically means that in attempt to make an application as flexible as possible it is implemented so that it creates a new platform that abstracts the original platform. I immediately associated to the API described below.

Let’s see if you can spot the Inner-platform effect in this URL, heavily anonymized but if you have been exposed to it you will probably recognize it immediately.

http://server/execute/clientSystemConnector
?service=createUser&key=id&value=97580
&key=name&value=David%20Eriksson&key=city&value=Ronneby

There are actually three examples of the Inner-platform effect in the above URL. The first is example is the “service” parameter. Instead of having separate URLs for separate services, the service name is a parameter. This means that the server platform first figures out what to about the /execute/clientSystemConnector path component of the URL, then the Inner Platform need to figure out how to handle the different possible values of the service parameter. (Anyone thinking about a giant “switch” statement?)  To avoid the Inner-platform effect, each service should have its own path in the URL.

The second example is blatantly obvious: having key and value parameters that specifies the names and values of the actual parameters. The impact of this “feature” is that the platform  provides a list of keys and a list of values to the inner platform, which must extract the actual parameters for use in the application. Without the Inner-platform effect the application could have received the parameters directly from the original platform.

It is probably not so easy to spot the third example, but it concerns authentication. Authentication (if it could be called that) for the services in this API is based on using different paths for different clients. So the above URL is used by the “clientSystem”. If “anotherClientSystem” need to execute the same service, the URL would be:

http://server/execute/anotherClientSystemConnector
?service=createUser&key=id&value=97580&...

So instead of using the built-in authentication mechanism (HTTP Basic Auth) in the platform, the Inner platform goes its own way.

How would I build an API to avoid the Inner platform? Except addressing the above issues I would also make it a POST (or PUT) request, as it handles the creation of a resource.

POST http://server/user/create HTTP/1.1
Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
Content-Type: application/x-www-form-urlencoded

id=97580&name=David%20Eriksson&city=Ronneby

Goodbye, Inner Platform!

PS. The origins of the API is probably 8-10 years old by now, and maybe it was a good idea at the time.

PPS. See the Inner-platform effect article on wikipedia for more examples.

I don’t do much C/C++ coding these days, even though I have been ogling Spindly – the C89 implementation of SPDY forked from libspdy by cURL author Daniel Stenberg.

For my current clients at work, I do Java coding or webMethods Integration Server development.

When I can spare some and energy for coding at home, it’s mostly web development in PHP, which brings me back to the tool-library pattern: Unfortunately I have not yet started using a smilar practice for my web development.

So what is the web site equivalence to the tool-library pattern? For a web site I mean that the “library” is a web service API that is consumed by the actual web site.  This is called First-Class APIs by Helgi Þormar Þorbjörnsson.

The API does not have to be public, but if it is, any other consumers of the API (for example a Smartphone app) will share the same API (or parts of it).

I’m currently rewriting my Swedish site for colloquial words and expressions from a hack (!) to a proper layered architecture. The next step will be to add new features and I hope to move these into an API.

1. Copy the /etc/dokuwiki/hostname directory and symbolic links
2. Copy the /var/lib/dokuwiki/hostname directory and symbolic links
3. Copy the template(s) from /var/lib/dokuwiki/tpl/templatename or /var/lib/dokuwiki/lib/tpl/templatename

Jag har skrivit detta blogginlägg enbart för att kunna länka till det när jag ser tävlingar på Facebook, så att jag slipper skriva samma sak om och om igen.

Ett tips när det gäller tävlingar på Facebook är att de har väldigt strikta regler för “promotions”, som det kallas! Om ni läser på Facebooks egna sida Promotions Guidelines samt artikeln Facebook Promotions: What You Need to Know t.ex. så förstår ni nog vad jag menar.

Det är många som inte har koll på reglerna, men om man ska ignorera dem så är det ju bra att kunna göra en riskanalys:

Hur stor är risken och följderna av att Facebook straffar er jämfört med risken och följderna av att era kunder och presumtiva kunder saknar tävlingar på er Facebook-sida?

Själv så känner jag inte till något fall där Facebook straffat arrangören av en tävling som bryter mot Facebooks regler, men som sagt tycker jag det är bra att vara medveten om risken.

Jag vill gärna höra om andras erfarenheter kring detta. Kommentera gärna detta inlägg!

For PHP there are at least the following implementations related to Dependency Injection:

• PHP-Dependency (Pd) - A PHP Dependency Injection Framework
• Pimple – A simple Dependency InjectionContainer for PHP 5.3
• Zend Framework 2 Dependency Injection

PHP-Dependency (Pd) works with @ annotation in the constructor comment, but why involve the constructor? And is a whole framework needed? PHP is not Java.

Pimple is very much a Dependency Injection Container, not so much about the injection. Simple, yes.

When it comes to Zend Framework 2 Dependency Injection I just can’t grasp how it simplifies anything. It seems to require a lot of boilerplate.

Unsatisfied with the above and a given a dose of NIH Syndrome, I decided to create my own DI system for PHP. After a bit of coding yesterday evening and night I named it Pebble and it is already on github! :-)

My current requirements on Pebble are as follows:

1. It must be possible to inject values of specific properties on class construction
2. It must work nicely in Zend Framework 1.x
3. It must not require any configuration files (and especially no XML)
4. It must be a single .php file for the core implementation
5. It must provide an open interface for extension and customization
6. It must work nicely with PHPUnit (especially with the getMock method)
7. It must work with autoloading of classes in PHP
8. It is allowed to use PHP 5.3 features
9. It is allowed to use @-based annotations in docComment, e.g. /** @something */

However, I have not yet used Pebble with PHPUnit, so I don’t know yet if that requirement holds!

Now is a good time for you to examine example1.php! The README is currently plain-text, I’ll format it later!

Marker tooltip

I start with the marker, as it is the simplest implementation:

function attachMarkerInfoWindow(marker, html)
{
	marker.infoWindow = new google.maps.InfoWindow({
		content: html,
	});
	google.maps.event.addListener(marker, 'mouseover', function() {
		marker.infoWindow.open(map,marker);
	});
	google.maps.event.addListener(marker, 'mouseout', function() {
		marker.infoWindow.close();
	});
}

var marker = new google.maps.Marker({
	position: new google.maps.LatLng(56.183182,15.593239),
});

attachMarkerInfoWindow(marker, '<strong>Softhouse office</strong>');

Polygon tooltip

A polygon does not contain a single position, so where should the tooltip show? One option is to calculate the center of the polygon using getCenter() on google.maps.LatLngBounds, but I decided to use the position of the mouseover event as the position of the InfoWindow. Think about it; the center of the polygon may not actually be inside the polygon!

As a bonus I change the fill opacity while the mouse cursor is inside the polygon.

function attachPolygonInfoWindow(polygon, html)
{
	polygon.infoWindow = new google.maps.InfoWindow({
		content: html,
	});
	google.maps.event.addListener(polygon, 'mouseover', function(e) {
		var latLng = e.latLng;
		this.setOptions({fillOpacity:0.1});
		polygon.infoWindow.setPosition(latLng);
		polygon.infoWindow.open(map);
	});
	google.maps.event.addListener(polygon, 'mouseout', function() {
		this.setOptions({fillOpacity:0.35});
		polygon.infoWindow.close();
	});
}

var polygon = new google.maps.Polygon(/* omitted for brevity */);
attachPolygonInfoWindow(polygon, '<strong>Info about this area</strong>');

To read and manage posts I use the Facebook Graph API, but there are a number of limitations:

• My application supports deleting posts, but Facebook does not allow applications to delete a photo
• Real-time Updates do not include support for groups (so I have to poll)
• Reading the Group feed and and using the since and until parameters do not guarantee that you find all posts in a high-traffic group, not even when using the previous and next links in the feed

Update Maybe I should start using FQL to query the Group feed?