Hi everyone, Is it possible to get the file name of a class? For example I have Foo.kt containing th...

# getting-started

[hichem fazai]

Hi everyone,
Is it possible to get the file name of a class? For example I have Foo.kt containing this class:

class Bar {
  init {
    // Here I want to get the name of the file (Foo)
  }
}

[Joffrey]

The source file doesn't necessarily exist at runtime. If your class is compiled into a .class file which is then packaged into a jar, what file name do you expect to get when you run this program?

[Joffrey]

Maybe you can use Java reflection like:

Bar::class.java.protectionDomain.codeSource.location.path

But it might not be 100% guaranteed to be accessible

[hichem fazai]

I tried this but it gives the path to the main function.

[hichem fazai]

If the source file doesnt exist in the runtime, so how the stacktrace shows it?

[hichem fazai]

If you execute this:

fun main() {
  Bar()
}

class Bar {
  init {
    throw Exception()
  }
}

output:
Exception in thread "main" java.lang.Exception
at Bar.<init>(Foo.kt:7)
at FooKt.main(Foo.kt:2)
at FooKt.main(Foo.kt)

[hichem fazai]

What do you think about the code below?

class Bar {
  init {
    val name = Exception().stackTrace.first().fileName.removeSuffix(".kt")
  }
}

[hichem fazai]

It works for me but looks very hacky

[Joffrey]

Seems indeed quite hacky to me. Maybe there is something in Kotlin's Metadata on the class that you could use. But I don't know much about this

[Joffrey]

Why are you interested in the filename at runtime btw?

[hichem fazai]

Here is my use case
I have a containing some classes that represents visual forms. That forms contains too many informations like title, labels of the fields, ... etc.
Now I want to provide a way to localize these forms in one xml file.
So the method will be like this:

fun localize(form: Form) {
  val name = form.fileName()
  // if language is french, look for localization in the file name-fr_FR.xml
  // if language is english, look for localization in the file name-en_GB.xml
}

[Joffrey]

So basically you want to associate Form instances with XML files based on the name of the file containing the form? Why not base this on a convention on class name? Or just specifying the file prefix explicitly in each form (which is more refactoring-proof)?

[hichem fazai]

Yes exactly,
I was trying to reduce code and make the program deduct that information.
Actually it's based on classname but to make the components in the form reusable it's possible to create a class for a field and insert it in a form. This way I will have to write an xml file foreach field. That's why I wanted to regroup localization of many classes in same xml file.
Also you're right about specifying the file prefix explicitly to avoid refactoring problem.

[hichem fazai]

Thanks alot for the ideas and help!
I invite you to take a look at this framework and the DSL I'm building:
https://github.com/kopiLeft/Galite#form