A toggle is a switch that allows users to set things up in two mutually exclusive states: on or off. It is common in technology, computing, and programming to use toggles to allow users to change settings or modes. It is also used as a verb, such as “He toggled between the screens during the video chat.”
In the context of web design, toggles are useful when there are only two options that an object can be in, such as showing and hiding navigation menus in a responsive web design or displaying different layouts based on screen size and device. They can also be useful when designing a user interface for a complex process where users must make multiple decisions and then confirm those choices.
Toggles are also a great tool for conducting A/B or Multivariate testing in production. By configuring a toggle to be either Off or On, and then assigning a different codepath to each cohort of users at runtime the system can compare the effects of these two codepaths against one another. This approach is very common in ecommerce systems where the product team wants to see what combination of options and features performs best for each customer type.
There are a variety of different ways to manage toggle configuration, from very simple and static approaches through to some highly sophisticated but very difficult to implement solutions. At the most basic level, a developer can hardcode a toggle to have either an on or off state by commenting in the appropriate place with an #ifdef flag. This method is typically only suitable for toggles that aren’t expected to have a large number of changes to their configuration over time, such as the Ops Toggles discussed below.
Another common way to manage toggles is to store them in a centralized repository. By doing this, a developer can easily create, edit and delete toggles by updating the code which stores them. This method can be very difficult to maintain at scale, however. When a large number of servers are involved it is often necessary to manually update config files which can cause significant issues if the config changes over time.
Ultimately, the choice of how to manage toggles is a matter of preference and the specific needs of an organization. In most cases, however, it’s good practice for teams to test the toggle configuration which they expect to go live in production (with all of the toggles which they’re releasing flipped On) along with a fallback configuration where those same toggles are flipped Off. This provides some peace of mind that existing or legacy behavior is preserved if the toggles are flipped Off, and new or future behavior is enabled if they’re flipped On. By ensuring that these two test configurations are consistent and available across all of a company’s development environments, developers can be confident that their new releases will behave as expected. By doing so they can be sure that they’re delivering the best possible experience for their customers.
