Scala-Play-Boilerplate

How to start?

1. Install docker and docker-compose.
2. Run docker-compose up -d in root directory to launch an instance of PostgreSQL.
3. Run sbt db_migrate to set up schema in PostgreSQL.
4. (Optional) Run sbt populate to populate database in development environment with fixtures.
5. Run sbt run to start the Play application.

Libraries Used

• Java8
• Play Framework
• Silhouette
• PostgreSQL
• Flyway
• Quill
• Enumeratum
• Circe
• Cats
• Shapeless
• PureConfig

Notes

Quill

val pagedQuery = quote { (offset: Int,limit: Int) => 
  query[Record].drop(offset).take(limit)
}
db.run(pagedQuery)(offset, limit)

Another possibility using lift and implicit quotation:

def pagedQuery(offset: Int,limit: Int) = 
db.run(query[Record].drop(lift(offset)).take(lift(limit)))

Also, you should avoid explicit typing your quotation with : Quoted[...] because it forces the quotation to be dynamic.

Authentication

Silhouette provides authentication for the application.

Error handlers

Global error handlers

By default Silhouette provides default error handlers via Guice dependency injection. To disable the default error handler, edit application.conf with the following content

play.modules.disabled += "com.mohiva.play.silhouette.api.actions.SecuredErrorHandlerModule"

Please refer to the list of error handlers section for an overview of all available error handlers and their modules.

Once the default handler module is disabled, you can bind your own implementation.

Global custom error handlers, CustomSecuredErrorHandler and CustomUnsecuredErrorHandler, redirect unauthenticated or unauthorized accesses to the appropriate landing pages.

Local error handlers

Adding authorization logic to secured endpoints

Silhouette provides a way do add additional authorization logic to secured endpoints. This is done by implementing an Authorization object that is passed to all SecuredRequestHandler and SecuredAction as a parameter. utility.authentication.AllowProvider checks whether a user logged in using a specific login provider. Could be useful for only exposing contents to specific login method.

Silhouette Events

Silhouette provides several events and event handling based on Akka's Event Bus. Silhouette itself doesn't listen for events. It is up to developers to decide if an event is useful or not.

PostgreSQL in Docker

Run docker-compose up -d to launch a PostgreSQL instance for development. By default the database can be connected to at localhost:27001.

Database Migration

When the Play application is launched, database migration is checked. If migration is not up to the latest version, an error message is displayed on the web page. Click on the Apply this script button to perform migration.

Alternatively, a manual migration can be performed via sbt. sbt db_migrate.

Database Population

Run sbt populate to populate database in development environment with fixtures.

TODO

1. Integrate with sbt-docker perhaps??

IntelliJ Idea Integration

doc

Set up Play to add hyperlinks to an error page. This will link to runtime exceptions thrown when Play is running in development mode.

Coursier Scala artifact fetching

Coursier is a dependency resolver / fetcher for Maven / Ivy. It can download artifacts in parallel.

Scala Formatter

A Scala formatter configuration file .scalafmt.conf is included in the project. Only git included files are formatted.

The sbt plugin, neo-sbt-scalafmt is used to integrate formatter with sbt. For compatibility with sbt 0.13, a workaround is used in build.sbt.

To format source code manually, run sbt scalafmt to format source code.

Scala WartRemover

At compile time, WartRemover

TODO

1. Update cats to 1.0.0 when released.
2. Update circe to 1.0.0 when its dependency on cats is updated.
3. Update slick-pg's when circe is updated.
4. Dev, test, prod environment.
5. Test code.
6. Hikari config.
7. Figure out a way to no longer require user to create Summary.scala file manually after cloning new project.