Two aura:id for one lightning component. Is it possible?

Question

Is it possible to have two aura:id for one lightning component?

I am feeling that I have an x-y problem, but I can not think any other solution her. So, let me explain the issue.

In a nutshell I have the following lightning app architecture:

Parent component(pc) has two child components (c1, c2). pc can have different components in place of c1 and c2. Sometimes c1 may dispatch a component event which pc should handle. pc should handle the event as follows: check that c2 has a specific component function if it does have it pc should call it.

In order to check for the function presence in c2 I need to access the component at first. I would like to use aura:id for that. But the thing is that components which may be in place of c2 may have different aura:id. So, I was hoping to add a second aura:id to c2 to extract whatever component there might be. In other words I would like to us aura:id here as an interface in OOP.

If you have different propositions on how to solve that I would be glad to hear them. In case I did not provide some information ask me and I will provide it.

Answer 1

Presuming that you're dynamically creating components (e.g. c1 and c2), you have total control over the aura:id. A component cannot define its own aura:id, only the aura:id for children within itself. From here, it follows that you're trying to figure out what type of component you're dealing with. For that, we use Component#getType. This tells you exactly what type of component you're dealing with.

For example:

var c2 = component.find("child2");
if(c2.getType() === "c:someComponent") { ...

Alternatively, if you're exposing actual aura:method references, you can also check for the presence of the function before calling it:

var c2 = component.find("child2");
if(c2.someMethod) { ...

Finally, if you are using interfaces, you can also check if a component is a type of interface:

if(c2.isInstanceOf("c:interfaceName")) { ...