Scala unused import statement with play framework in IntelliJ

Question

I'm trying to learn scala and play framework. I choosed IntelliJ Idea as ide. The problem is editor gives warning on imports like ; "unused import statements"

import play.api._
import play.api.mvc._

Also give warnings on declerations like ; "Cannot resolve symbol Controller"

object Login extends Controller

How can i remove warnings?

Steps i followed;

Create template idea project with play command;

Add scala compiler and library into external libraries.

IntelliJ Idea Version : 12.1 Community Editon

Did you activate the Scala plugin? And I'm sad to say that the Play! Framework is only supported in the Ultimate edition: IntelliJ IDEA Editions Comparison. But I'm not sure that that has anything to do with this problem. — maba
yeap already activated the scala plugin. i guess ultimate edition is the solution unfortunately. — Fatih Donmez
I usually run the Ultimate edition but installed the Community edition right now and I don't get the same error as you. The controllers are fine. — maba
it's good to know that you didn't experience the problem with community edition, so then i was missing something — Fatih Donmez

maba maba · Accepted Answer · 2013-04-10T09:48:09

This is how I did it (I'm using Play! 2.1.0):

C:\dev>play new community
       _            _
 _ __ | | __ _ _  _| |
| '_ \| |/ _' | || |_|
|  __/|_|\____|\__ (_)
|_|            |__/

play! 2.1.0 (using Java 1.7.0_15 and Scala 2.10.0), http://www.playframework.org

The new application will be created in C:\dev\community

What is the application name? [community]
>

Which template do you want to use for this new application?

1             - Create a simple Scala application
2             - Create a simple Java application

> 1
OK, application community is created.

Have fun!


C:\dev>cd community

C:\dev\community>play idea
[info] Loading project definition from C:\dev\community\project
[info] Set current project to community (in build file:/C:/dev/community/)
[info] Trying to create an Idea module community
[info] Updating {file:/C:/dev/community/}community...
[info] Done updating.
[info] Excluding folder target
[info] Created C:\dev\community/.idea/IdeaProject.iml
[info] Created C:\dev\community\.idea
[info] Excluding folder C:\dev\community\target\scala-2.10\cache
[info] Excluding folder C:\dev\community\target\resolution-cache
[info] Excluding folder C:\dev\community\target\streams
(commons-codec_commons-codec_1.6_test,List(commons-codec_commons-codec_1.3))
(org.apache.httpcomponents_httpcore_4.1.3_test,List(org.apache.httpcomponents_httpcore_4.0.1))
(org.apache.httpcomponents_httpclient_4.1.2_test,List(org.apache.httpcomponents_httpclient_4.0.1))
[info] Created C:\dev\community\.idea_modules/community.iml
[info] Created C:\dev\community\.idea_modules/community-build.iml

C:\dev\community>play compile
[info] Loading project definition from C:\dev\community\project
[info] Set current project to community (in build file:/C:/dev/community/)
[info] Compiling 5 Scala sources and 1 Java source to C:\dev\community\target\scala-2.10\classes...

enter image description here

The Unused import statement is because no classes are being used in that package. This line can safely be removed by optimizing import: Ctrl + Alt + o.

In this case I didn't add any scala libraries at all. I just compiled from the command line.

Scala unused import statement with play framework in IntelliJ

1 Answers