NAME
Froody::Error - Froody error class
SYNOPSIS
use Froody::Error qw(err);
# throw an error
eval {
Froody::Error->throw("user.problem", "user '$userid' not known", $data);
};
# "user.problem, user '9BC6DD8C-1E25-11DA-98F1-DDB51046DF9C' not known, "
print $@->code .", ". $@->msg
# and a stacktrace
print $@->stacktrace
# print the data section
print Dumper $@->data;
# check if the error is the right class
if (err("user"))
{
...
}DESCRIPTION
Froody::Error is the Froody error class. It's designed to be powerful, yet simple to use. It's a subclass of Error.pm.
Often, the easiest way to create an error response from within Froody is to throw a Froody::Error. This will be caught by the server, and it'll be turned into an error response before dispatching it to the client.
Standard Froody::Error errors that are thrown by Froody itself indicating that something is wrong with Froody (e.g. you've asked for a method that doesn't exist, or you've ommited a required parameter) are listed in Froody::Error::Standard.
throw
To throw an error with Froody::Error you just have to call the throw method with up to three arguments:
# throw an error with its code, reporting the default message
Froody::Error->throw("what");
# throw an error with its code, reporting a custom message
Froody::Error->throw("what", "bang");
# throw an error with code, custome message, and some data
Froody::Error->throw("what", bang", { thingy => "broken" });In each case this creates a new Froody::Error object and then dies with it.
The first argument is the code that defines the type of error that we're throwing. The second argument is a message, a string which describes the error. If this error is translated to a Froody error response then these will be mapped to the code and message attributes of the <err> repectivly. The third argument is the data, a set of parameters that decribe in a computer understandable format what causes the error. This data potentially will be transformed into the children of the <err> tag based on what specification is in the errortypes of the repository.
Hierarchal Error Messages
Error messages use 'dot' notation to indicate what error messages are sub-types of other error messages.
For example:
Froody::Error->throw("io", "Bad IO");And, a more particular error:
Froody::Error->throw("io.file", "There was a problem with the file");And an even more particular error
Froody::Error->throw("io.file.notfound", "File not found");But all these methods can be detected with isa_err
if ($@->isa_err("io")) { ... }Or even better with the err functions (as this won't go "bang" if $@ is a hashref)
use Froody::Error qw(err);
if (err("io")) { ... }METHODS
- new( message )
-
define
- code
-
Return the error code. Read only.
- message / msg / text
-
Returns the error message. Read only.
- data
-
Return (a copy of) the error data. Read only.
- stringify
-
Returns a string containing both the error code and the error text, and a stacktrace. This is what is returned if you try and use a Froody::Error in string context.
BACKWARDS COMPATIBILITY
We used to have a different sort of error. Rather than having hierarchal error codes that looked like this:
<err code="file.rwerr" message="unable to write to disk" />We used to use simple numbers and have errors that looked like this:
<err code="12" message="unable to write to disk" />This is fine. The key here to remember is that numbered error codes are a subset of the hierarchal error codes. The numbers are all just top level errors that are made up of alphanumerics that are just digits. It's just a not very hierarchal hierarchal error code.
BUGS
None known.
Please report any bugs you find via the CPAN RT system. http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Froody
AUTHOR
Copyright Fotango 2005. All rights reserved.
Please see the main Froody documentation for details of who has worked on this project.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.