app                      → Application sources
 └ assets                → Compiled asset sources
    └ stylesheets        → Typically LESS CSS sources
    └ javascripts        → Typically CoffeeScript sources
 └ controllers           → Application controllers
 └ models                → Application business layer
 └ views                 → Templates
build.sbt                → Application build script
conf                     → Configurations files and other non-compiled resources
 └ application.conf      → Main configuration file
 └ routes                → Routes definition
public                   → Public assets
 └ stylesheets           → CSS files
 └ javascripts           → Javascript files
 └ images                → Image files
project                  → sbt configuration files
lib                      → Unmanaged libraries dependencies
logs                     → Standard logs folder
 └ application.log       → Default log file

• Play! Framework is Stateless and RESTFUL by default

• No Servlets == No servlet containers ( Tomcat, Jetty )  

• All requests enter a Play! app via a { java. nio } Non-Blocking I/O Server called Netty  that never touches HTTP Session ( ever ).

• Having a static routes file located in the conf directory :

#  HTTP        
# request      URI                     Controller.method
#  type
   
   GET     /                       controllers.Application.index()

   GET     /FlightSearch           controllers.FlightsController.flightSearch()

   POST    /Login/ResetPassword    controllers.SecurityManager.doReset()

   DELETE  /Cart/Remove            controllers.Cart.remove(cartId: Long)
     
    

• In the conf folder of the application directory, lives a lonely configuration file: application.conf

• Similar to a Java Properties File:

# Default Routes file: Default to Routes in the root package
#application.router=my.application.Routes
# Database configuration
# ~~~~~
# You can declare as many datasources as you want.
# By convention, the default datasource is named "default"
# Uncomment below or use the H2 in-memory database.
db.default.driver=com.mysql.jdbc.Driver
db.default.url="jdbc:mysql://localhost:3306/flights"
db.default.user=...
db.default.password=...
    

• Zero XML configuration

terminal~/dev/FlightClub$ play run

[info] Loading project definition from /Users/terminal/dev/FlightClub/project

--- (Running the application from SBT, auto-reloading is enabled) ---


[info] play - Listening for HTTP on /0:0:0:0:0:0:0:0:9000



(Server started, use Ctrl+D to stop and go back to the console...)

• Demo to come later  ;-)

• Simple Build Tool  -  the build tool used by 

• Dependency Management 
• build.sbt equivalent to maven's pom.xml

name := "FlightClub"

version := "1.0-SNAPSHOT"

libraryDependencies ++= Seq(
  javaJdbc,
  javaEbean,
  cache,
  "mysql" % "mysql-connector-java" % "5.1.18"
)

play.Project.playJavaSettings
	

• SBT compiles both and  sources.

• Reloads code changes on the fly :

--- (Running the application from SBT, auto-reloading is enabled) ---
...
[info] Updating {file:/Users/terminal/dev/Flightclub/}flightclub...
[info] Resolving ...
[info] Done updating.
[info] Compiling 3 Scala sources and 2 Java sources to /Users/terminal/dev/Flightclub/target/scala-2.10/classes...

• Means that every update to the code only requires a refresh        ( or two ) of the browser.

• Ebean is an ORM similar to Hibernate

• HTTP Session-less Transactions

• Highly integrated into Play! 

• Evolutions help to handle database migrations

• Auto-generates sql scripts in response to changes to your @Entity models
  

• These run at start-up on your database

• The Database we were given had no problems at all

• Flight Search approach
• Server vs Client-side templating
• Views
• views.scala.html templates
• Responsive design

• Compiled Assets
• LESS CSS
• CoffeeScript
• Forms & Data-Validation

Form<User> userForm = form(User.class);
@Entity
public class User {
    @Constraints.Required
    @Constraints.Email
    public String email;
    @Constraints.MinLength(6)
    public String password;
    
    public String validate() {
        if(authenticate(email,password) == null) {
            return "Invalid email or password";
        }
        return null;
    }
}  
    

if(userForm.hasErrors()) {
    return badRequest(form.render(userForm));
} else {
    User user = userForm.get();
    return ok("Got user " + user);
}
    

Variables are pretty easy
@black: #FFCC00
#header{
    color: @black
}

Mixins are an easy way of including properties from one rule-set to another.
.bordered {
  border-top: dotted 1px black;
  border-bottom: solid 2px black;
}

#menu a {
  color: #111;
  .bordered;
} 

Nesting Rules
#header {
  color: black;
  .navigation {
    font-size: 12px;
  }
  .logo {
    width: 300px;
  }
}