GlobalWrapError<St> class abstract

This wrapper will be given all errors thrown in your actions (including those of type UserException). Then:

  • If it returns the same error unaltered, this original error will be used.
  • If it returns something else, that it will be used instead of the original error.
  • It it returns null, the original error will be disabled (swallowed).

IMPORTANT: If instead of RETURNING an error you THROW an error inside the wrap function, AsyncRedux will catch this error and use it instead the original error. In other words, returning an error or throwing an error has the same effect. However, it is still recommended to return the error rather than throwing it.

Note this wrapper is called AFTER the action's ReduxAction.wrapError, and BEFORE the ErrorObserver.

A common use case for this is to have a global place to convert some exceptions into UserExceptions. For example, Firebase may throw some PlatformExceptions in response to a bad connection to the server. In this case, you may want to show the user a dialog explaining that the connection is bad, which you can do by converting it to a UserException. Note, this could also be done in the ReduxAction.wrapError, but then you'd have to add it to all actions that use Firebase.

Another use case is when you want to throw the UserException.cause which is not itself an UserException, and you still want to show the original UserException in a dialog to the user:

Object wrap(Object error, [StackTrace stackTrace, ReduxAction<St> action]) {
  if (error is UserException) {
    var hardCause = error.hardCause();
    if (hardCause != null) {
      Future.microtask(() =>
        Business.store.dispatch(UserExceptionAction.from(error.withoutHardCause())));
      return hardCause;
    }}
  return null; }

You should not use GlobalWrapError to log errors, as the preferred place for doing that is in the ErrorObserver.

Constructors

GlobalWrapError()

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited
wrap(Object error, StackTrace stackTrace, ReduxAction<St> action) → Object?

Operators

operator ==(Object other) → bool
The equality operator.
inherited