Category: Useful Methods
2021-11-07
Convert Boolean to Yes/No in XAML
On user interfaces, it maybe necessary to present a user-friendly version of a Boolean value. I.e. Instead of true or false, it is presented as yes or no. With Xamarin Forms and MVVM XAML bindings, it is possible to add converters on bindings. As can be seen in this example, it is really easy to […]
2021-07-03
Convert to Relative Time
Displaying date and time on a user interface is useful, but it is not always the most user-friendly way to present information. Imagine a social media website, which displays recent comments, but displays the date and time when a photo or comment was published. It requires more than just a quick glance to work out […]
2020-07-31
Auto-Formatting UK Postcodes and validation
If you were to ask a user to provide a postcode little or no validation on, you would probably find that a postcode such as OX26 6XE would end up as something like Ox266xe or ox2 66xe. For some applications, this maybe acceptable. But for others, especially when integrating with address APIs, formatting maybe crucial. […]
2020-02-23
Improving MVVM INotifyPropertyChanged
With a project that uses MVVM (Model-View-View Model) design pattern, INotifyPropertyChanged is often used to detect a property value change in an object. This is particularly pertinent as far as creating a two-way data binding. Typical Implementation Normally, the INotifyPropertyChanged is implemented in a similar pattern to the code below. This is something that makes […]
2020-02-23
Time-based One Time Password
A nice easy-to-use RFC-6238 based algorithm, that provides a HMAC-based One-Time Password authentication. The algorithm is based on one outlined in this article here. The interval is in seconds. It dictates how long before a TOTP expires. For example, if a TOTP is generated at 14:20 and the interval is 120 seconds. The TOTP will […]
2018-10-16
UK National Holidays API
The UK Government have a useful web page for all of the UK’s National Holidays, such as Easter and Christmas. This can be found with the link here https://www.gov.uk/bank-holidays. In addition to this, there is also a really handy public API, which is the JSON representation of the web page (Just add .json to the […]
2018-02-18
Random AlphaNumeric Generator
Recently I needed to write a simple token generator for a project. In order to make it print-friendly and easy to read, I decided to make it an uppercase alphanumeric string. The code uses the ASCII (American Standard Code for Information Interchange) numeric representation of the character. A-Z (uppercase) is any number between 65 and 90. To […]
2017-07-30
Determining Colour Contrast
I was recently working on one of my home projects that required colour coded drop down list items according to the option they related to. In my project, it was going to be colour coded categories. I wanted to implement colour coding to act as a visual aid for the user interface. Rather than store […]