Play framework tutorial: Cannot resolve symbol 'index'?

24
votes

I followed a tutorial here and although I got the entire tutorial working just fine, one of the classes in my IntelliJ project is marked with "red warnings". I cannot figure out what the problem is here? The project works but it shows these warnings? Any ideas on what this is and how to fix it? In the tutorial, about 3.5 minutes into it, the red marks magically disappear and the video presenter doesn't explain it.

enter image description here

7
playframeworkintellij-ideaplayframework-2.0
What version of IntelliJ are you using? Make sure that you have the Play 2.0 support plugin installed. – maba
I am using the community edition 12.1.3. I heard it has built-in support. Is that true? – djangofan
I don't use IntelliJ, but in the screenshot in your question the import views.html.* is greyed out, doesn't that mean it's been commented out? – 2manyprojects
@2manyprojects - No, that is just a warning message. That being said, are the static 'index' and 'routes' objects in the 'views' package? If not, what package are they in? I suspect I am just missing a static import that IntelliJ is not smart enough to resolve? – djangofan
The routes object is at controllers.routes. Maybe it's just been a long day but I'm not sure I know what you mean by the index object ... do you mean the compiled version of a index.scala.html file? That would be at views.html.index assuming it was in the root of the views folder of the project, otherwise views.html.<package>.index. – 2manyprojects

7 Answers

32
votes

This process worked for me:

  1. go into [File -> Project Structure -> Modules -> [YourAppModule] -> Sources Tab]
  2. navigate to the "target/scala-[version]/src_managed" directory (panel on the right).
  3. Right click the "main" directory and flag it as a source folder.
  4. Right click "controllers" and "views" and remove the "sources" flag (you should see the controllers and views folder become package directories).
  5. Apply -> OK -> recompile.

from https://github.com/playframework/playframework/issues/1784#issuecomment-26345523

8
votes

I managed to make it work on IDEA Community 14 by solely cleaning IDEA cache (File -> Invalidate Caches / Restart)

8
votes

Views / templates are not classes, which is why IDE cannot recognize them. IDE should be configured to look for the compiled version of the views. This click will fix your issue

enter image description here

5
votes

The routes file and the views are compiled only when the project is first loaded in the browser. Till then, IntelliJ shows the error as it cannot find those classes. But the errors magically dissppear when you run the application and load it into browser.

You can verify this in the play console. After you do a play run , and load the url localhost:9000 in the browser, you can see compilation messages in the play console saying

...compiling 22 scala sources....

1
votes

Go to the Run configuration for your Play project and remove the 'Make' step from the "Before Launch" section. Then, IntelliJ would simply run the Play project without attempting to compile, and the views will get compiled automatically.

Until the views are compiled, IntelliJ doesn't know they exist, and can't make the project itself. Clearly this is a problem with IntelliJ's plugin, but since you're already relying on Play to do your compiling dynamically, this workaround doesn't hurt the workflow too much.

1
votes
  1. Open "Project" sidebar
  2. Go to target/scala-<version>/src_managed
  3. Right-click the src_managed, "Mark Directory As"/"Generated Source Root"
  4. Subdirectories of src_managed are from a strange reason marked as source roots. You can disable it.
  5. Enjoy.

Note that javascript routes seem to be still ignored from a strange reason, so this is not a perfect solution. Nevertheless, it is better than nothing.