Elvis operator in expressions: `?.`

Currently a.b.c will thrown an error in expression if a is null. To suppress null dereferencing we should support a?.b.c which would short circuit further evaluation if a is null. In this way we could have explicit notation which would show which values could be null.

Syntax to fallow dart proposal: https://github.com/gbracha/nullAwareOperators/blob/master/README.md

[jelbourn]

Feels kind of weird to me; it’s surprising to have language extensions within the binding expression syntax.

This might also need some more thinking, but I don’t see this as being that useful. If angular defaults to gracefully handling null dereferencing in expression then the developer doesn’t have to care whether something is loaded lazy or not. The times when people do care is when something needs to be shown in place of the pending data, which will still be handled with an if

[leonard84]

@vicb @mhevery Sorry for resurrecting this but I want to point out that the safe-navigation-operator and the “Elvis” operator are two different things. See Wikipedia , Groovy-Elvis, Groovy-Safe-Navigation. The Elvis operator is more akin to the Null coalescing operator with the difference that it tests for “truthy” instead of null for the lhs.

displayName = user.name ? user.name : 'Anonymous'   
displayName = user.name ?: 'Anonymous'                  // <- Elvis operator

I think it is bad practice to take established terminology from other languages and change its meaning. What angular currently has is a safe-navigation-operator and not the Elvis operator. Calling it Angular “Elvis” operator ( ?. ) does not make it better 😉