Installation

1. Download the zip via the download button below.
2. Extract and upload to your wordpress installation plugin folder.
3. Activate the widget plugin via the admin panel of your blog.
4. In the admin panel widgets section, drag the Simple Weather widget to the desired position in the sidebar.
5. Select temperature unit, Celcius or Farenheit.
6. Done!

Usage

To use the widget, in the desired posts simply add a cityName and possibly weatherBase custom fields with the name of the city for which you wish to display the weather. The weatherBase is only needed if Google weather API does not recognize the city in cityName.

If neither cityNamenor weatherBase is entered, the widget will not display.

Download

When facing chemical equilibrium problems of the type

it is often useful to construct logarithmic concentration versus pH diagrams to illustrate how the concentrations of the ions are dependant of the pH-value.

The theory behind the diagram is not too complicated and the construction is straightforward. However, generating nice looking diagrams can be time-consuming and tedious and therefore I wanted to share my excel template for generating dibasic log concentration – pH diagrams.

This template is intended for dibasic systems and can ideally be used for school assignments or teaching. The excel template will generate a diagram looking like the below example:

Any feedback is appreciated and can be left via the comment function below.

No need to bother with complicated field formulas and tedious chart formatting – that is already done for you!

Dowload template here:

Only edit cells with green text to avoid breaking any formulas and functionality.

Dowload:

$page = file_get_contents('http://www.pagetobechecked.com');
		$dom = new DOMDocument();
		@$dom->loadHTML($page);
		$xpath = new DOMXPath($dom);
		$hrefs = $xpath->evaluate("/html/body//a[substring(@href,1,25)='http://www.yourdomain.com']");
		if($hrefs->length>0) {$link_exists = true;} else {$link_exists = false;}
}

Swine flue cases in Sweden 2009 (click for larger image)

The results are interesting to say the least. From this simple test it seems that in this particular instance AdSense relies entirely on the filename / URL alone to determine content targeting. If the file is called world_of_warcraft_guide.htm, then ads about World or Warcraft would show, regardless of page title and page content (see images below).

Furthermore, if the filename was buy_car_online.htm, then ads about car rental would display, despite the title being DVD-player (in swedish) and the content being about DVD players.

See for yourselves.

Further, the security benefits from masked passwords are likely minimal for most users and applications. However, there are situations and applications that legitimately benefits from masked password fields, and to cover all bases that best solution might be to enable the user to decide wether masking is warranted or not.

This can be achieved with a simple javascript toggle function:

function switchType(obj){
if(obj.getAttribute('type')=='text')
{
obj.setAttribute('type','password');
}else{
obj.setAttribute('type','text');
}
obj.focus();
}

This function is then called when the user checks a checkbox:
<input onclick="switchType(document.form1.password);" type="checkbox" />

To view an example, click here. The full source code can be seen by right clicking and selecting view source code (or the equivalent)

“Common sources of location information include Global Positioning System (GPS) and location inferred from network signals such as IP address, RFID, WiFi and Bluetooth MAC addresses, and GSM/CDMA cell IDs”

This functionality was earlier available through 3rd part solutions such as Google Gears, but now it is natively supported in Firefox.

The key function is: navigator.geolocation.getCurrentPosition()
If you have Firefox 3.5+ you may test the Geolocation API here (please let me know if the result is correct).

I also make use of the API in my geographical chat/game Zapin (in Swedish, but have a look).

Here is the javascript that makes it happen:
var oRequest = new XMLHttpRequest();
var sURL = "geodecode.php?lat="+position.coords.latitude+"&lon="+position.coords.longitude;

oRequest.open("GET",sURL,false);
oRequest.setRequestHeader("User-Agent",navigator.userAgent);
oRequest.send(null)

var MyAdress = 'Time:' + position.timestamp + '<br>Latitude:' + position.coords.latitude + '<br>Longitude:' + position.coords.longitude + '<br>Accuracy:' + position.coords.accuracy + 'm<br>Altitude:' + position.coords.altitude + oRequest.responseText;
document.getElementById('adressField').innerHTML = MyAdress;
}

if (navigator.geolocation) {
// Geo request
navigator.geolocation.getCurrentPosition(GeoDecode);
}

The trick is to add a listener when creating the markers, and then use getElementID to select the corresponding item in the document, identified by a uniqe ID.

(Java script)
var marker = new GMarker(point, customIcons[\"standard\"]);
GEvent.addListener(marker, \"mouseover\", function() {
marker.setImage(\"../images/marker_h.png\");
var listItem = document.getElementById(\"item-\" + j);
listItem.style.backgroundColor = \"#FFFA5E\";
});
GEvent.addListener(marker, \"mouseout\", function() {
marker.setImage(\"../images/marker.png\");
var listItem = document.getElementById(\"item-\" + j);
listItem.style.backgroundColor = \"#FFFFFF\";
});

The HTML could for example look like this:

<li id="item-1">Some content</li>

Maybe not the most elegant solution, but it does the job.

Finally, some useful resources for Google map developers:
Google Maps API Tutorial by Mike Williams
Simple to use tool to make custom markers