A toggle is a user interface element used to switch on or off features. It’s a way to allow users to update settings or view content that is otherwise hidden, or to change the default state of the element. Toggle switches are most commonly found on mobile devices, in browsers or apps that support drag-and-drop. They can also be implemented in hardware, such as buttons or switches on a computer keyboard or video game controller.
In software development, toggles are often used to roll out or back features during code deployment. They help maintain stability and shorten the time it takes to fix bugs when compared with traditional trunk-based development. Using toggles also helps reduce the risk of breaking existing functionality when introducing a new feature.
The word toggle comes from the mining term “Canary in a Mine,” which was used to warn miners of toxic gases. Toggles are useful for detecting dangerous conditions and can be rolled back without impacting the whole application. They are also used to manage access to features for certain groups of users, such as premium members of a service.
How Toggle Works
A toggle can be defined as a Boolean variable with two states — On and Off. A toggle can be switched between states by using an event or action that triggers the corresponding value to be set. In this way a program can track the current toggle state and take appropriate actions depending on the state. For example, a button clicked in an ecommerce application can switch an item from “available” to “in stock.”
Toggle Configuration
Most commonly toggles are configured via static files or an external feature flag service. However, as the number of toggles grows it can become cumbersome to modify the configuration via these methods. To resolve this many organizations opt to build out some form of admin UI which allows system operators, testers and product managers to view and modify the toggle configuration.
When it comes to designing an effective toggle user interface, there are a few key considerations. The most important thing is to clearly identify what the toggle does, so that there’s no ambiguity about which state it is in. This can be achieved by describing the toggle’s behavior in the label, providing an interface icon that conveys the current state and updating the button’s appearance based on its current state.
It’s also important to test the toggle configuration that is expected to be deployed in production, including any toggles that are currently flipped Off. To avoid surprise regressions in a future release many teams also perform some tests with all toggles flipped On, so that they can detect any unexpected changes in behavior. As with all things, it’s always better to be proactive than reactive when it comes to software testing. That’s why a solid quality assurance plan should be in place, which includes the use of toggles to test and refine new features.
