Error, Warning, and Informational Messaging

MOOSE provides several macros/functions for emitting errors, warnings, and informational messages:

mooseError(args): Emits an error with a message formed by concatenating args.
mooseDocumentedError(repo_name, issue_num, args): Same as mooseError(args), but for errors tied to defects documented in an issue tracker. See Documented Errors.
mooseAssert(condition, msg): In a debug executable, emits an error with message msg if the boolean value/expression condition is false. If not in a debug executable, does nothing.
mooseWarning(args): Emits a warning with a message formed by concatenating args. If the command-line flag --error is supplied, then these warnings are promoted to errors.
mooseDeprecated(args): Emits a warning related to a deprecated object/feature. If the command-line flag --error-deprecated is supplied, then these warnings are promoted to errors.
mooseInfo(args): Emits an informational message formed by concatenating args. Example:
mooseInfoRepeated(args): The same as mooseInfo(args) but only prints a message once, even if called multiple times.

note:Warnings in repeating sections

For warnings in sections of the code that are often executed, it is recommended to leverage the SolutionInvalidInterface, which will only output the warning once but keep track of the occurence of the problem. It can also force the solver to reject a converged solution that still presents the warning/invalid condition.

Documented Errors

The mooseDocumentedError(repo_name, issue_num, args) function is used for errors that are tied to defects documented in the issue tracker of the framework or an application. This function is preferred over mooseError when it applies. For example, when there is some missing functionality or incompatibility, one can create an issue in the issue tracker for that repository, and then a developer can call mooseDocumentedError with the registered repository name repo_name (see below), the issue number issue_num (provided as an integer, not a string), and the error message arguments args.

To register a repository name for an application, one must use registerRepository(repo_name, repo_url) in their application's registerAll method, where repo_url corresponds to the URL of the Github or Gitlab repository; for example,


void
ExampleApp::registerAll(Factory & f, ActionFactory & af, Syntax & s)
{
  // some statements
  registerRepository("exampleapp", "github.com/someuser/exampleapp");
}

One can then call mooseDocumentedError with the registered repository exampleapp:


mooseDocumentedError("exampleapp", 235, "Feature ABC is not currently supported.");

where this error is documented in exampleapp's issue #235 at github.com/someuser/exampleapp/235.

Note that for errors in the MOOSE framework itself, the MOOSE repository is registered with the name moose already, which occurs in the constructor of MooseApp, from which every app should inherit.

Documented Errors