[scaldi-play 0.5.8] StackOverflow in Play 2.4 With Custom ErrorHandler

[Neil Chaudhuri]

I have a Play 2.4 application with a custom error handler with the following signature:

class MyErrorHandler(env: Environment, config: Configuration, sourceMapper: OptionalSourceMapper, router: () => Router, mailer: Mailer)
  extends DefaultHttpErrorHandler(env, config, sourceMapper, new Provider[Router] {def get() = router()})

Note the Mailer as the last parameter in the constructor. I have bound Mailer and the custom handler like this:

bind[Mailer] when inProdMode to new ProdMailer
bind[Mailer] when inDevMode to new MockMailer

bind [HttpErrorHandler] to injected [MyErrorHandler] ('router -> injectProvider[Router])

The problem is I get a StackOverflowError on startup with this setup. If I remove the mailer from the methods where I use it but keep it in the constructor, the application starts just fine. Only when the mailer does something do I get the error.

Can anyone tell me where I messed up my bindings?

Thanks.

[Neil Chaudhuri]

Actually check that. I just found another StackOverflowError on startup with the Mailer in the signature. So it seems to be intermittent--the worst kind of bug--with the Mailer in the parameter list but happens every time with the Mailer in the parameter list and used in a method..

[Oleg Ilyenko]

Hi Neil,

I think it's similar kind of issue I also faced recently with `HttpRequestHandler` (https://groups.google.com/forum/#!topic/scaldi/4beiEok7D84). Making `mailer` a provider should solve this issue. Maybe you can try something like this:

class MyModule extends Module {

  // ...

  bind [HttpErrorHandler] to injected [MyErrorHandler] ('router -> injectProvider[Router], 'mailerProvider -> injectProvider[Mailer])

}

class MyErrorHandler(env: Environment, config: Configuration, sourceMapper: OptionalSourceMapper, router: () => Router, mailerProvider: () => Mailer)

    extends DefaultHttpErrorHandler(env, config, sourceMapper, new Provider[Router] {def get() = router()}) {

  lazy val mailer = mailerProvider()

  // ...

}

It's doesn't look very nice, but looks like it's necessary at the moment because of the way play wires all dependencies. I will investigating why it's the case for the `HttpErrorHandler` (as well as `HttpRequestHandler`)

Cheers,

Oleg

[Neil Chaudhuri]

That seems to have worked. Thanks for the tip! Hopefully one day we can figure out what Play is doing to cause this issue.

[Oleg Ilyenko]

FYI: looks like the module loading bugfix also resolved this issue, and allows to inject mailer without making it a provider: https://groups.google.com/d/msg/scaldi/SWSLOAWhazY/w1PTxrHFDgAJ (fixed in scaldi-play v0.5.9)