A modern programming language that makes developers happier.

kotlinlang

image.png

```Row {
  Text("Hello")
  Box(
    modifier = Modifier.padding(16.dp)
//                .thenIf(true) { border(10.dp, Color.Red) }
      .border(10.dp, Color.Red)
      .size(60.dp)
      .background(Color.Blue)
  )
  Text("World!")
}```
result is :

```Row {
  Text("Hello")
  Box(
    modifier = Modifier.padding(16.dp)
      .thenIf(true) { border(10.dp, Color.Red) }
      .size(60.dp)
      .background(Color.Blue)
  )
  Text("World!")
}```
result is:

@Composable with thenIf has a larger Padding, but I don't know why this is the case, I would expect the result to be the same as the first one :thinking_face:

oh btw, in this case, my thenIf function is

```inline fun Modifier.thenIf(
  condition: Boolean,
  modifier: Modifier.() -&gt; Modifier,
): Modifier = if (condition) this.then(modifier()) else this```

if i use:
```inline fun Modifier.thenIf(
  condition: Boolean,
  modifier: Modifier.() -> Modifier,
): Modifier = if (condition) modifier() else this```
and
```Row {
  Text("Hello")
  Box(
    modifier = Modifier.padding(16.dp)
      .thenIf(true) { border(10.dp, Color.Red) }
      .size(60.dp)
      .background(Color.Blue)
  )
  Text("World!")
}```
the result will be the same as the first one

I think the problem might be with inline + then, but is there anything special about the `then` method? :thinking_face:

No, There is no issues with `thenif` modifier. Basically, it's used as alternative of clickable.

Because `if (condition) modifier() else this` will return `modifier()` or receiver’s `Modifier`
When `this.then()` version will return receiver’s `Modifier` + `modifier()` or just receiver’s `Modifier`

but my function is `inline` , the `if (condition) modifier() else this` block will be replace by `Modifier.xxxx.modifier()`  :thinking_face:

I’m not so sure about it :slightly_smiling_face:

Not using `this.then` is actually en error: <https://googlesamples.github.io/android-custom-lint-rules/checks/ModifierFactoryUnreferencedReceiver.md.html>

I think the compiler gets confused because there is still an occurrence of `this` in the body, it’s there but used wrongly :thinking_face:

I believe `this.then(modifier())` is causing the receiver to be used twice

Because the receiver is in scope it becomes `this.then(this.modifier())` which is using the padding modifier twice, hence the larger padding.

oh :hushed: it seems to make sense, I accidentally mixed up the scope of lambda :sob:

`modifier()` usually already does `this.then` for you
the correct version is `if (condition) this.modifier() else this`

yes, I didn't realize that my lambda's were in the same Modifier scope before :sob::sneezing_face: