A toggle is a piece of hardware that can be moved between a number of positions to change its function. For example, a toggle can be used to switch between different color schemes in an application or to hide or show content. Toggles can also be used in software to allow developers to test changes with small groups of users before they are fully rolled out to the entire user base. In this article we will look at how to use toggles in continuous development and some best practices for managing them.
The word toggle is a combination of two words: “on” and “off”. Toggles can be on or off, but they are usually on one time only. This is in contrast to a button which can be pressed again and again to change its state, but it cannot be on more than once at a time.
In software, toggles are usually implemented as Boolean variables with values of either True or False. When a variable is set to be true, it means that the feature is active and should be used. The other way around, when a variable is set to be false, it means that the feature should not be used and should be disabled.
Feature toggles are essential tools for teams using agile methodologies and Continuous Delivery. Traditionally, new features would have been written on code branches which would then go through a lengthy testing and QA process before they could be integrated back into trunk code. Feature toggles let teams release code with new features hidden behind them until they’re ready for Beta or full rollout, and they can even act as circuit breakers in the event of a bug fix.
The main use of a feature toggle is to experiment with functionality with a group of users before it is released to the general public. For example, an e-commerce site may want to test whether adding a shopping cart is effective for their users. This would be a great use of a permission toggle.
It’s important for teams to think carefully about the configuration of their toggles. While it’s tempting to try to cover all possible combinations of states by hardcoding them into the code, this can lead to confusion and can be very difficult to debug weeks or months down the road. If a feature toggle can be set to multiple states it’s important for teams to choose their default carefully, as this will be the behavior that will be enacted by the system in most cases.
Another key aspect of managing a feature toggle is ensuring that it’s named clearly and correctly, so that it makes sense to anyone who reads the code in the future. The best practice is to name a toggle after the feature it’s implementing, but other best practices include using a short, clear description and ensuring that the label clearly describes what the toggle will do when pressed.
