iOS 8: options for presenting Action Extensions to users?

Question

After reading the Apple documentation on extensions, it's not clear how Action Extensions get presented to users. The docs mention the Bing translate use case where actions are presented after users tap the Share button. But what if an app, say a chat app, doesn't have a share button? Another example is if the calling app (not the containing app of the extension) presents an option to invoke an Action Extension.

Are these the only two options? In other words, if an app lacks a Share button and doesn't integrate your extension, there's no way to present an Action Extension?

Answer 1

That is correct. Actions are always initiated by the user, and always from system-provided UI.

Answer 2

Extensions are presented as a possible in a UIActivityViewController. The host app provides the UIActivityViewController with the data context. If your extension adheres to this context, it will be available in the list.

If someone writes an app without the UIActivityViewController then they won't be able to use your extension.

Answer 3

May be help you. Apple provides sample code for ImageInverter: Creating Action Extensions

There are concept for Action Extensions.