Ramblings of Sverrir Sigmundarson

Mastering cell validation lists in Excel

Cell validation lists or lookup lists can be very helpful for users when filling out forms or sheets in Excel. They instruct the user on the possible values allowed and perform basic validation on that input. However it can be extremely hard to implement this feature in the correct way especially when they need to be ammendable by the users.
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Extracting values from HTML form elements in webpages is a messy business. Here is the ultimate guide and example code showing how to automatically extract everything you want into a fully customizable JSON data structure. Super Easy!
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When using PHP to consume high precision data from location APIs such as the Google Maps and Google Elevation APIs extra care needs to be taken with the parsing of JSON data. This is due to a long outstanding bug in the PHP json parser engine which has only been fixed now in PHP v7.0.

The underlying VBA object model in Excel is very powerful but it is not straight forward to use. Here is the definite guide to supercharge your VBA code by connecting it to the Excel chart event model.
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Combining Mp4 video files automatically

I recently had to join a lot of mp4 video files together to make them easier to play on my Xbox. I wanted the resulting file to have chapter marks at the joining points so that I could quickly skip between episodes when watching. There is no such tool out there so I built a script to do this.
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Jekyll 3 Pagination Gem

I recently learned that the true and tested pagination gem for jekyll, jekyll-paginate, had been decommissioned and removed from Jekyll 3. So I decided to build a new fully backwards compatable and enhanced replacement for it.
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Google Analytics and server-side PHP

A complete guide with working code on how to integrate the Google Analytics Measurement Protocol API to measure custom events on your PHP server. Especially useful when you're interesting in tracking usage and exceptions for your web-based APIs.
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Writing a Python webserver in 10 seconds

Python has a built in support and classes to run a simple webserver straight from the command line. With a few extra lines of code you can extend the built in type and get a very decent testing server that can be run from any computer.
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HTML5 Video Playback on Xbox and the Playstation

The ultimate guide to how to create and program a website that can play mp4 videos in the native browsers on both the Xbox and Playstation consoles. The code supports playing multiple videos in sequence according to a playlist and will auto run when ready.
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Passing post variables to includes in Jekyll

In Jekyll includes do not have access to variables defined in your posts or pages. But don't worry here is how you can do it very easily.
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