What's the idiomatic way to : if I have a listOf<String>(...) and then I map it to a listOf&lt...

# announcements

[Pablo]

What's the idiomatic way to :
if I have a listOf<String>(...) and then I map it to a listOf<MyUiClass> to once I have this listOf<MyUiClass> remove an item of it if let's say today == whatever.

Pseudo :

val myList = listOf<String>("example1","example2",...)
val mappedUiClass = myList.map{myMapper.map(it)}
//Here I'd like to remove one exactly item if a condition is true.

So for instance if mappedUiClass contains
{id=1,name="Jhon", type: "MyType1"}
{id=2,name="Hual", type: "MyType2"}
{id=3,name="Hjdu", type: "MyType3"}

If the condition is true I just want to keep in mappedUiClass the id1 and id3, so if condition == true remove MyType2.

[diesieben07]

myList.mapNotNull { s -> myMapper.map(s).takeIf { it.type != "MyType2 } }

[Pablo]

But here's meesing the condition. The condition would be like
if(today.isRaining()) then remove the item that the type is MyType2

[diesieben07]

myList.mapNotNull { s -> myMapper.map(s).takeUnless { today.isRaining() && it.type == "MyType2 } }

[Pablo]

Can not do the it.type inside the takeUnless

[diesieben07]

wdym "can not do"? Whats the error?

[Pablo]

the it is the list<UiClass>

[diesieben07]

Can you show the actual code oyu tried?

[Pablo]

sure

val listString = getListOfStrings()
val listUi = listString.map{it.map(it)}.takeUnless { today.isRaining()}

[Pablo]

This is not complaining

[Pablo]

But then when I try to get the type it says that it is a list instead of the item itself

[diesieben07]

it.map(it) that doesn't make sense 😄

[Pablo]

note that it.map(it) is like extension function

[Pablo]

Is doing the job, don't worry

[Pablo]

Didn't want to put more things

[diesieben07]

You need mapNotNull and inside the mapNotNull you need takeUnless

[diesieben07]

Your code looks nothing like what I posted...

[diesieben07]

val listUi = listString.mapNotNull { it.map(it).takeUnless { /* condition */ } }

[Pablo]

I just want you to know that inside of val listUi there's the list mapped already so it's a listOf<Ui> instead of listOf<String>

[diesieben07]

Yes but you want listUi to be filtered, no?

[diesieben07]

You don't want an element in listUi for all elements in listString

[diesieben07]

You just want some

[Pablo]

Oh wait

[Pablo]

the takeUnless

[Pablo]

is inside the map...

[Pablo]

Right?

[diesieben07]

Yes

[Pablo]

That's why I was getting the list...

[Pablo]

Ok, let me try

[diesieben07]

hence mapNotNull, so it ignores everything that doesnt match the condition

[Pablo]

yes

[Pablo]

Thanks looks like is working 😛