See scaladoc at top of file for general picture.
See scaladoc at top of file for general picture.
See SemanticFailures.Conflict for intended use.
Plural counterpart of ConflictFailure
Plural counterpart of ConflictFailure
See scaladoc at top of file for general picture.
See SemanticFailures.Conflict for intended use.
See scaladoc at top of file for general picture.
See scaladoc at top of file for general picture.
See SemanticFailures.Denied for intended use.
Plural counterpart of DeniedFailure
Plural counterpart of DeniedFailure
See scaladoc at top of file for general picture.
See SemanticFailures.Denied for intended use.
THERE'S EVERYTHING WRONG WITH ERRORS!
THERE'S EVERYTHING WRONG WITH ERRORS!
The more meaningful design decisions are the ones made in failures.scala file detailing the definitions of various busymachines.core.exceptions.FailureMessage
Since the types here are a minority, the design here emulates the one from the other more commonly used file.
Should be extended sparingly outside of this file.
Should be extended sparingly outside of this file.
Most likely you need to extend one of the other cases.
THERE'S NOTHING WRONG WITH FAILURE!
THERE'S NOTHING WRONG WITH FAILURE!
There, now that that got your attention, let me elaborate on the intention of these types.
Basically, they are a semantically richer way of expressing common failures when developing backend-servers.
Furthermore, these exceptions being part of the
of the application
—by reading this file— you have not gauged their full potentiality, yet.
The intention is to give richer interpretations to these "common failures"
in other core
module than could be done to the likes
of Throwable.busymachines-commons
The reason why there is a trait FailureMessage, and some types that extend Exception is that the potentiality of these types can be achieved either through a monad stack approach to building applications, or to a more vanilla scala approach, respectively.
There are two quasi-parallel hierarchies of failures: I) the FailureMessage representing one single failure II) the FailureMessages representing a container of multiple FailureMessage. The intended use of the FailureMessages.id (and other ones inherited from FailureMessage is to signal the general "context" within which the specific FailureMessages.messages where gathered.
There are the following semantically meaningful exceptions (with their plural counterparts elided) that you ought to be using: - NotFoundFailure - SemanticFailures.NotFound - UnauthorizedFailure - SemanticFailures.Unauthorized - ForbiddenFailure - SemanticFailures.Forbidden - DeniedFailure - SemanticFailures.Denied - InvalidInputFailure - SemanticFailures.InvalidInput - ConflictFailure - SemanticFailures.Conflict
Each described in the SemanticFailures docs.
These definitions are also quite flexible enough to allow multiple styles of active development:
1) The quick and dirty, "better than RuntimeException" style. Basically, you just wind up using the default constructors on the companion object, or the companion object itself
//I know I am in the middle of my domain problem, and I know that here //I can fail because "I did not find something", so I just quickly use: option.getOrElse(throw NotFoundFailure) option.getOrElse(throw NotFoundFailure("this specific option, instead of generic"))
This style should be kept just that, "quick and dirty". After the first iteration of the implementation these failures should be replaced by the ones in style 2)
2) The long term style. Where you subclass NotFoundFailure into a more meaningful exception specific to your problem domain, supply some context via the parameters, and assign it an (preferably) application-wide unique FailureID.
object RevolutionaryDomainFailures { case object CannotBeDone extends FailureID { val name = "rd_001" } //... and many others } case class SolutionNotFoundFailure(problem: String) extends NotFoundFailure( s"Solution to problem $problem not found." ) { override def id: FailureID = RevolutionaryDomainFailures.CannotBeDone override def parameters: Parameters = Map( "problem" -> problem ) } object Main { //... solutionToPVSNP.getOrElse(throw SolutionNotFoundFailure("P vs. NP")) solutionToHaltingProblem.getOrElse(throw SolutionNotFoundFailure("Halting Problem")) //how refined you want your failures, that's up to you. }
31 Jul 2017
FailureMessage counterpart, but for situations when multiple such messages can occur.
FailureMessage counterpart, but for situations when multiple such messages can occur.
FailureMessages#id, and FailureMessages#message should be used to convey the general context withing which FailureMessages#messages where gathered.
Similar to Failure but encapsulate multiple causes.
Similar to Failure but encapsulate multiple causes.
Primarily used as containers for validation failures.
See scaladoc at top of file for general picture.
See scaladoc at top of file for general picture.
See SemanticFailures.Forbidden for intended use.
Plural counterpart of ForbiddenFailure
Plural counterpart of ForbiddenFailure
See scaladoc at top of file for general picture.
See SemanticFailures.Forbidden for intended use.
See SemanticErrors.InconsistentState for intended use.
See scaladoc at top of file for general picture.
See scaladoc at top of file for general picture.
See SemanticFailures.InvalidInput for intended use.
Plural counterpart of InvalidInputFailure
Plural counterpart of InvalidInputFailure
See scaladoc at top of file for general picture.
See SemanticFailures.InvalidInput for intended use.
See scaladoc at top of file for general picture.
See scaladoc at top of file for general picture.
See SemanticFailures.NotFound for intended use.
Plural counterpart of NotFoundFailure
Plural counterpart of NotFoundFailure
See scaladoc at top of file for general picture.
See SemanticFailures.NotFound for intended use.
See scaladoc at top of file for general picture.
See scaladoc at top of file for general picture.
See SemanticFailures.Unauthorized for intended use.
Plural counterpart of UnauthorizedFailure
Plural counterpart of UnauthorizedFailure
See scaladoc at top of file for general picture.
See SemanticFailures.Unauthorized for intended use.
Marker traits, so that both the Failure and Failures can be marked with the same semantic meaning
31 Jul 2017