h1. Overview

This is general purpose library. It provides some basic utilities for the scala project. I wrote this project mostly for myself, but I hope you can find it also helpful. If you have some interest, ideas, or found some bugs pleas feel free to give me your feedback. In this case I can put more efforts to improve project and make it more useful for others.

Project covers number of areas, that will be described in the next sections.

h1. Maven configuration

In order to use scala-essentials withing Maven2 project you should add one new repository in your pom.xml:

    
        
            angelsmasterpiece-repo
            Angel's Masterpiece Maven 2 Repository
            http://github.com/OlegIlyenko/angelsmasterpiece-maven-repo/raw/master
        
    

Now you can add this dependency:

    
        org.angelsmasterpiece
        scala-essentials
        1.0-SNAPSHOT
    

h1. Command line processing

It's easy and type safe to process command line arguments with CommandLine class. You can define your command line like this:

class MyCommandLine extends CommandLine {
    val argument1 = Argument[String]("argument1", optional = true)
    val argument2 = Argument[Double]("argument2", "arg2", description = "Double argument")
    val help = FlagArgument("help", "h", description = "Show this help")

    val flag = FlagArgument("flag-arg", "fl", "My super flag")
}

Now you can start you application like this:

@executable --argument1 SomeString -arg2 1.5 -fl@

In your code you can use it like this:

val cl = new MyCommandLine
cl parseOrExit args

val doubleVal = cl.argument2() + 2.0  // = 3.5

cl.argument1.value match {
    case Some(v) => // do something ...
    case None => // do something ...
}

It also contains some other features like validation and usage printer

h1. Configuration

So you can define your configuration:

case class MyConfig(s: ConfigurationSource) extends Configuration {

    // You can provice source like this.
    // By default SystemConfigurationSource would be used.
    implicit val implicitConfigurationSource = s

    val appName = Property[String]("common.appName", "Application name", "My app")
    val version = Property[Double]("common.version", "Application version", default = 2.1)
    val file = Property[File]("common.file", description = "Additional configuration file")

    val database = new Configuration {
        val driver = Property[String]("database.driver", default = "com.mysql.jdbc.Driver")
        val url = Property[String]("database.url", "JDBC Database URL")
    }

    // It's optional step, but you can use it for validation during instantiation.
    // You can also validate later manually by invoking validate(method on configuration instance)
    validate()
}

In this case configuration would be also automatically validated during instantiation.

You can use it like this:

val config = MyConfig(PropertiesConfigurationSource("config.properties"))

println(config.appName())
println(config.database.driver())
println(config.database.url())

You can also use different configuration sources. They can be found in the package org.angelsmasterpiece.scala.essentials.config. Following configuration sources are available (but you can also write your own):

• SystemConfigurationSource - from System.getProperty(...)
• MapConfigurationSource - from used map
• PropertiesConfigurationSource - from properties file, or properties instance
• CommandLineConfigurationSource - integrate with CommandLine class (takes properties by longName or alias)
• AggregatingConfigurationSource - aggregates several configuration sources

h1. Helpers

There are also some helpers, that provide useful functions and implicit conversions.

h2. IO Helper

With this helper you can do following things:

closeable(new PrintWriter("file.txt")) { writer =>
    writer.println("Hello World!")
}

File("file.txt").text match {
    case Some(text) => println(text)
    case None => println("Nothing")
}

File("file.txt").lines

File("file1.txt") write "Hello world 1!"

It also contains more features. Please see the sources to find out more.