Back in Chapter 3, Go to the Rescue!, we saw that the Go compiler has built-in support for the conditional inclusion of source files based on a system of environment variables and build tags. As an application adds more functionality, especially from a platform-integration perspective, it is possible that the toolkit you have chosen will not provide all of the functionality you are looking for. When this happens, the code will need to be updated to handle platform-specific functionality. To do so, we will use a variation of the conditional build – using well-named files instead of build tags (as used in Chapter 11, Navigation and Multiple Windows). This is easier to read at the project level and should indicate clearly which files will be compiled for which platform.
Let's create a simple example: we want to show a notification...
