Wind Rose Chart Extension

    Recently I developed my first QlikView extension object, and it actually wasn't that hard. Yes, I have done some web development in the past, and I am sure that made things a little easier. But there is some excellent sample code on the web and QlikView desktop installs with plenty of examples to get you started. If you are looking to get started with QlikView extensions then I highly recommend this excellent tutorial (which is where I started):

    http://qliktips.blogspot.com.au/2011/01/beginners-guide-to-qlikview-extension.html

     

    The object that I needed to build was a Wind Rose Chart, which is a chart used to display wind speeds around the points of the compass. This particular design comes from the Australia Bureau of Meteorology and is explained here: http://www.bom.gov.au/climate/averages/wind/wind_rose.shtml

    Below is a screen shot of how it should look once you install the customisation and feed it some data. I am posting what I built here as it may assist someone who needs either:

    - a Wind Rose Chart in QlikView

    - a starting point for a similar radial bar chart extension

      - an example of using the Raphael javascript library to build custom visualisations in QlikView

      - an example of a custom extension

     

    wind_rose.jpg

     

    Finally, a little info about how I built this. As I mentioned above, first I started with the tutorial. Then, trawling around the web I found a product called Raphael (http://raphaeljs.com) which is a set of javascript functions you can use to build svg files on the fly. Raphael allows you to build an image using data from QlikView and then display that image in QlikView. As a starting point for how to use Raphael with extension objects I then had a look at the heat map example that comes with QlikView desktop (in C:\Program Files\QlikView\Examples\Extensions). Note that when you install the extensions they unzip to C:\Users\[your user ID]\AppData\Local\QlikTech\QlikView\Extensions. Take a look at the files there, they are just text files containing XML or javascript. Then I started building my own extension bit by bit and testing at each stage.

     

    Attached is the install file for the extension, which is a qar file extension. Just double click on it to install it. Note that qar files are just zip files containing the necessary components of the extension. These get copied to the path mentioned above when you double click on the qar file. If you change the file extension to zip you can open them like any other zip and take a look inside. Also attached is a document explaining a little about how to configure the extension, as it requires values in a specific format to work properly.

     

    Note that this example extension is provided 'as is' and is not supported in any way.