Sometimes when writing software, the client of your library wants to pass something in, but you don't really want to know what they thing is.
For example you may have a view that you want to return a specific event on. But by passing in the event you are coupling to it. You basically have three options.
// 1. Couple to the event -> Coupling
func didSelectArticle(withURL url: URL, analyticsEvent: Analytics.Actions.Activation) {
// 2. Pass in `Any` -> Must cast `Any` to specific type in client
func didSelectArticle(withURL url: URL, analyticsEvent: Any?) {
// 3. Use a generic -> No casting required
func didSelectArticle(withURL url: URL, analyticsEvent: T) {The problem with #1 is you introduce hard coupling into your API. Now you library need to know about event.
The problem with #2 is you decouple, but they you need a cast in the client to convert Any into whatever object you want.
#3 is the right way to go because with generics, no casting is required.
protocol SupportArticleViewDelegate: AnyObject {
func didSelectArticle(withURL url: URL, withUserInfo userInfo: Any?)
}And then use it in the client class like this.
func didSelectArticle(withURL url: URL, withUserInfo userInfo: Any?) {
guard let event = userInfo as? Analytics.Actions.Activation else { return }
let activationData: [String: AnyHashable] = [
"supportArticleUrl": url.absoluteString
]
analytics.trackEvent(withTitle: event.rawValue, context: activationData)
}