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Mastering play framework for scala

By : Shiti Saxena
Book Image

Mastering play framework for scala

By: Shiti Saxena

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Mastering play framework for scala
Shiti Saxena
May, 2015 | 274 pages
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Table of Contents (21 chapters)
Mastering Play Framework for Scala
Mastering Play Framework for Scala
Credits
Credits
About the Author
About the Author
Acknowledgments
Acknowledgments
About the Reviewers
About the Reviewers
www.PacktPub.com
www.PacktPub.com
Preface
Preface
Free Chapter
1
Getting Started with Play
Getting Started with Play
Venturing into the world of Play
Summary
2
Defining Actions
Defining Actions
A dummy Artist model
Actions
Request body parsers
Extending a parser
Exploring the results
Asynchronous Actions
Content negotiation
Filters
Action composition
Troubleshooting
Summary
3
Building Routes
Building Routes
Introduction to Play routes
Reverse routing
Assets
Configuring route definitions
Configuring request parameters
Troubleshooting
Summary
4
Exploring Views
Exploring Views
Diving into Scala templates
Generating forms
Internationalization
Scala templating in Play
Troubleshooting
Summary
5
Working with Data
Working with Data
Introducing models
JDBC
Anorm
Slick
ReactiveMongo
The Cache API
Troubleshooting
Summary
6
Reactive Data Streams
Reactive Data Streams
Basics of handling data streams
Iteratees
Enumerator
Enumeratees
Summary
7
Playing with Globals
Playing with Globals
GlobalSettings
The life cycle of an application
The request-response life cycle
Summary
8
WebSockets and Actors
WebSockets and Actors
An introduction to WebSockets
WebSockets in Play
Actor Model
Introducing Akka Actors
WebSocket using Iteratee
WebSocket using Actors without Iteratees
Closing a WebSocket
Troubleshooting
Summary
9
Testing
Testing
The setup for writing tests
Unit testing
Dissecting PlaySpecification
Unit testing a controller
Functional testing
Summary
10
Debugging and Logging
Debugging and Logging
Debugging a Play application
Experimenting in a Scala console
Logging
Play's logging API
Log configuration in Play
Summary
11
Web Services and Authentication
Web Services and Authentication
Calling web services
OpenID
OAuth
Summary
12
Play in Production
Play in Production
Deploying a Play application
Configuring for production
Enabling SSL
Using a load balancer
Troubleshooting
Summary
13
Writing Play Plugins
Writing Play Plugins
Plugin definition
Plugin declaration
Exposing services through plugins
Tips for writing a plugin
Summary
Index
Index

Troubleshooting

  • What is the equivalent of interrupting Actions in GlobalSettings for WebSockets? What if we want to refuse a WebSocket connection when certain headers are missing? Something similar to the following code snippet didn't work as expected:

    override def onRouteRequest(request: RequestHeader): Option[Handler] = {
    if(request.path.startsWith("/ws")){
      Option(controllers.Default.error)
    } else
      super.onRouteRequest(request)
  }

    Interrupting WebSocket from the global object does not work as it does for Actions. However, there are other means of doing so: by using the tryAccept and tryAcceptWithActor methods. A WebSocket definition can be replaced by the following code:

    def wsWithHeader = WebSocket.tryAccept[String] {
    rh =>
      Future.successful(rh.headers.get("token") match {
        case Some(x) =>
          var channel: Concurrent.Channel[String] = null
          val out = Concurrent.unicast[String] {
            ch =>
              channel = ch
   ...
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