Sleipnir is a generator of native Scala bindings for rest.li Pegasus schemas. The code is implemented with the following ideas in mind:

1. Use as much of Pegasus infrastructure as possible: schema files parsing is reused, generated classes extend RecordTemplate/DataTemplate and work on top of DataMap and so on.
2. Low tech code generation: we use Twirl templates (aka Play Scala templates), more on this here.

The sleipnir-sample project uses Sleipnir to generate Scala bindings for a Play server.

You can use Sleipnir in a couple ways: as a command line tool or as an SBT plugin.

In SBT, run:

project sleipnirGenerator
runMain net.yefremov.sleipnir.Sleipnir <resolving path> <source dir> <target dir> [namespace prefix]

For example, to generate bindings for the schemas in the sample-data project, run:

runMain net.yefremov.sleipnir.Sleipnir  sample-data/src/main/pegasus sample-data/src/main/pegasus sample-data/src/main/codegen

To use Sleipnir in your SBT project, you should add the sleipnir plugin, and add its settings to your project.

1. Add the following line to plugins.sbt:

    addSbtPlugin("net.yefremov.sleipnir" % "sleipnir-sbt-plugin" % "<version>")
   

2. Add the sleipnir settings to the project that defines the Pegasus schemas:

    import net.yefremov.sleipnir.sbt.SleipnirPlugin._
   
    lazy val exampleProject = Project(...)
        .settings(sleipnirSettings: _*)
        .settings(
          sleipnirSourceDirectory := baseDirectory.value / "data" / "src" / "main" / "pegasus",
          sleipnirDestinationDirectory := baseDirectory.value / "data" / "src" / "main" / "codegen"
        )
   

The changes above will enable generation of Scala bindings for PDSC files defined within your project. You may also want to generate bindings for PDSC files defined in a dependency of your project. This is necessary if the dependency does not generate Scala bindings as a part of its own build process.

To generate bindings for PDSC files of all dependencies:

    lazy val exampleProject = Project(...)
        .settings(sleipnirDownstreamSettings: _*)

Also, you may enable filtering of dependencies that will be processed:

    lazy val exampleProject = Project(...)
        .settings(sleipnirDownstreamSettings: _*)
        .settings(dataTemplatesDependenciesFilter := DependencyFilter.allPass -- moduleFilter(organization = "net.yefremov.example-service"))

Only dependencies unfiltered by the dataTemplatesDependenciesFilter will have Scala bindings generated.