SCALA-NATIVE.md

Scala Native and Scala.js Help

The release has minimal capabilities at this time so the following is an example of how to use the API.

Dependency for Scala Native and Scala.js

Use three percent signs %%% instead of two for dependency resolution.

// sconfig uses "provided" so you have a choice of the java.time API you use
// Refer to your preferred java.time project for version to use
libraryDependencies ++= Seq(
  "org.ekrich" %%% "sconfig" % "x.y.z",
  "org.ekrich" %%% "sjavatime" % "a.b.c"
)

Please refer to the sjavatime home page for the current version.

Read from String example

This assumes that you read a file into a configStr first. Other methods that don't use File or URL should also work.

import org.ekrich.config.ConfigFactory

val configStr =
        """
          |maxColumn = 100
          |project.git=true
          |align = none
          |danglingParentheses = true
          |newlines.neverBeforeJsNative = true
          |newlines.sometimesBeforeColonInMethodReturnType = false
          |assumeStandardLibraryStripMargin = true
        """.stripMargin

val conf = ConfigFactory.parseString(configStr)

val maxCol = conf.getInt("maxColumn")
val isGit = conf.getBoolean("project.git")

Using Reader - StringReader example

Both JS and Native now support java.io.Reader which allows using sconfig to parse all supported formats by passing a filename with extension. See the following examples from the shared ConfigFactoryTest file.

val filename = "/test01.properties"
val fileStr =
    """
      |# test01.properties file
      |fromProps.abc=abc
      |fromProps.one=1
      |fromProps.bool=true
      |fromProps.specialChars=hello^^
      """.stripMargin

// create Reader
var test01Reader = new StringReader(fileStr)

val config = ConfigFactory.parseReader(
  test01Reader,
  ConfigParseOptions.defaults
    .setSyntaxFromFilename(filename)
)
val specialChars = config.getString("fromProps.specialChars")

In Scala Native java.io.FileReader is available so you can create a FileReader from a File.

How to read a HOCON configuation file using Scala Native

In order to read a configuration file you need to know the relative path from where the executable was started or use an absolute path. If the Scala Native executable is run from sbt it will have the current working directory equal to the directory at the base of your project where sbt was started. If curious or the situation is unclear you can run the following code inside your Scala Native application to find the path.

val dir = System.getProperty("user.dir")
println(s"Working Dir: $dir")

Continuing the same thought process you can use the following code to read the file from a simple sbt project where the src directory is at the top level of your project and you are using the run command. If you package your application or run the application executable directly, then making the path relative to the binary with the code above could be your best option. Another option is to use the "user.home" or the "user.dir" property to configure the file path. Note: When the executable is added to the path, the current working directory is where you start the executable from so keep that in mind

import java.io.File
val file = new File("src/main/resources/myapp.conf")
// ConfigDocument
val configDocument = ConfigDocumentFactory.parseFile(file)
// or Config
val config = ConfigFactory.parseFile(file)

Using this code with the code above gives you a working solution to use sconfig with Scala Native.

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