is there a more idiomatic way of writing this ``` ...

# announcements

[Hexa]

is there a more idiomatic way of writing this

if(!item.name.isNullOrEmpty()){
            itemMap["name"] = AttributeValue().withS(item.name)
        }

[Tolriq]

Usually I do

item.name?.takeif { it.isNotEmpty() }?.let { AttributeValue().withS(it) }

[Hexa]

Screen Shot 2018-11-25 at 12.46.14.png

[Hexa]

my compiler doesnt like the takeif function

[Hexa]

is that a function that I have to write or am I missing a depedency? @Tolriq

[hallvard]

Personally, I find @Tolriq's solution less clear, actually. The advantage of isNotNullOrEmpty() is that you get more checks into one, and yet the semantics of it is very clear to the human eye.

[Hexa]

yea it seems less readable @hallvard, but I'm curious how it works

[Tolriq]

it's takeIf sorry. in his case seeing that ?. is a warning it means the String can't be null so isNotEmtpy is enought. For the rest it's a matter of reading.

[Tolriq]

Depends on what you mean readable. This is a one liner that is more functional in reading. It says given a value take it if XXX then if it's not null do YYY

[Tolriq]

This is readable and functional, just needs to be used to it, but takeIf takeUnless and all those are here for that purpose.

[hallvard]

Sure, it's functional and kotlinish. I still think doing just one check is more readable in this case, but you are free to disagree, of course. And I do agree that there are plenty of other use-cases where takeIf is very useful.

[Tolriq]

Well the other advantage is that it properly handles smart cast for complex object 🙂 If item.name is mutable and could have been null then the if code would still require a !! after the item.name.

[Tolriq]

For simple case that that simple if is OK, for proper general way and Kotlin way, takeIf is a better way.

[Hexa]

thanks @Tolriq

[Tolriq]

Just to show the problem (your item.name can't be null but to have the idea)

class Item(var name: String? = null)

val item = Item()

fun test() {
    if (!item.name.isNullOrEmpty()) {
        var t: String = item.name
    }
}

That does not work compiler will complain that item.name is mutable and can't be smartcast 😉