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Error Classes Ruby


This method is similar to #backtrace, but the backtrace is an array of Thread::Backtrace::Location. For example: class MyLibrary class Error < RuntimeError end class WidgetError < Error end class FrobError < Error end end To handle both WidgetError and FrobError the library user can rescue end blocks. StandardError The most standard error types are subclasses of StandardError. his comment is here

share|improve this answer answered Feb 9 at 19:16 Huliax 4831617 add a comment| up vote 0 down vote Given what the ruby core documentation of Exception, from which all other errors The design of a robot and thoughtbot are registered trademarks of thoughtbot, inc. See the subclass list below for defaults for raise and rescue. The backtrace is an array of strings, each containing either “filename:lineNo: in `method”‘ or “filename:lineNo.” def a raise "boom" end def b a() end begin b() rescue => detail print detail.backtrace.join("\n") https://ruby-doc.org/core-2.2.0/Exception.html

Ruby Exception Classes

Now, this method is not affected by #set_backtrace. Home Core 2.2.0 Std-lib 2.2.0 Downloads Home Classes Methods In Files error.c Parent Object Methods ::exception ::new #== #backtrace #backtrace_locations #cause #exception #inspect #message #set_backtrace #to_s Files grammar.en.rdoc test.ja.rdoc contributing.rdoc If you want to help improve the Ruby documentation, please visit Documenting-ruby.org.

To do so, we need to choose an Exception-descended class (or classes) to catch. It is recommended that a library should have one subclass of StandardError or RuntimeError and have specific exception types inherit from it. When that’s not possible On occasion, that won’t be possible. Ruby Error Class Hierarchy static VALUE exc_set_backtrace(VALUE exc, VALUE bt) { return rb_iv_set(exc, "bt", rb_check_backtrace(bt)); } to_s → string click to toggle source Returns exception’s message (or the name of the exception if no message

Was Isaac Newton the first person to articulate the scientific method in Europe? Ruby Standarderror Please enable JavaScript to view the comments powered by Disqus. NOTE: The second strategy below uses the rails pretty string methods, such as demodualize, which may be a little complicated and therefore potentially unwise to do in an exception. https://ruby-doc.org/core-2.1.5/StandardError.html This page was generated for Ruby 2.1.5 Ruby-doc.org is a service of James Britt and Neurogami, an application development company in Scottsdale, AZ.

Live curious. Classes In Ruby Tutorial Otherwise, returns true if exc and obj share same class, messages, and backtrace. Normally this returns the exception’s message or name. Best-case scenario In the best-case scenario, we know exactly which error (or errors) can occur.

Ruby Standarderror

The crucial part appears to be overriding #message. You could also add more arguments to the method signature, should you need. Ruby Exception Classes Otherwise, create a new exception object of the same class as the receiver, but with a message equal to string.to_str. Ruby Argumenterror static VALUE exc_to_s(VALUE exc) { VALUE mesg = rb_attr_get(exc, rb_intern("mesg")); if (NIL_P(mesg)) return rb_class_name(CLASS_OF(exc)); return rb_String(mesg); } Commenting is here to help enhance the documentation.

Please enable JavaScript to view the comments powered by Disqus. static VALUE exc_equal(VALUE exc, VALUE obj) { VALUE mesg, backtrace; const ID id_mesg = idMesg; if (exc == obj) return Qtrue; if (rb_obj_class(exc) != rb_obj_class(obj)) { int status = 0; ID Programs may make subclasses of Exception, typically of StandardError or RuntimeError, to provide custom classes and add additional information. What’s the right granularity of that class? Ruby Rescue

share|improve this answer edited Apr 15 '14 at 6:16 answered Apr 19 '13 at 15:31 Stefan 50.8k36094 I'll accept your answer because you showed me the entire syntax. The built-in subclasses of Exception are: NoMemoryError ScriptError LoadError NotImplementedError SyntaxError SecurityError SignalException Interrupt StandardError -- default for rescue ArgumentError UncaughtThrowError EncodingError FiberError IOError EOFError IndexError KeyError StopIteration LocalJumpError NameError NoMethodError What I do know You can declare your custom error class and let it inherit from StandardError, so it can be rescued: class MyCustomError < StandardError end This allows you to static VALUE exc_initialize(int argc, VALUE *argv, VALUE exc) { VALUE arg; rb_scan_args(argc, argv, "01", &arg); rb_iv_set(exc, "mesg", arg); rb_iv_set(exc, "bt", Qnil); return exc; } Public Instance Methods exc == obj →

Home Core 2.3.1 Std-lib 2.3.1 Downloads Home Classes Methods In Files error.c Parent Object Methods ::exception ::new #== #backtrace #backtrace_locations #cause #exception #inspect #message #set_backtrace #to_s Files grammar.en.rdoc test.ja.rdoc contributing.rdoc Classes In Ruby On Rails The rescued class must descend from Exception Ruby’s Exception class hierarchy starts with Exception. Now, this method is not affected by #set_backtrace.

Normally this returns the exception’s message or name.

This allows the user to rescue a generic exception type to catch all exceptions the library may raise even if future versions of the library add new exception subclasses. Addressing the OP's issue, you could also pass the message as an additional argument and store anything you like. Thank you. Ruby Class Definition Yes, I did omit Errno::* for brevity's sake.

Hot Network Questions What happens if anti-refelctive coating is fully ruined or removed from lens most outer surface? Twitter / nicksieger: At Cholon with some great guys ... Exception Descendants of class Exception are used to communicate between Kernel#raise and rescue statements in begin ... If you wish to post a correction of the docs, please do so, but also file bug report so that it can be corrected for the next release.

So, we need to catch and handle those errors. When an exception has been raised but not yet handled (in rescue, ensure, at_exit and END blocks) the global variable $! Thanks! –MarioDS Apr 20 '13 at 8:22 1 Here we doing rescue Exception, but why not rescue MyCustomError? –Dfr Jun 22 '13 at 10:45 @Dfr I've updated the If you wish to post a correction of the docs, please do so, but also file bug report so that it can be corrected for the next release.

Exceptions that are StandardErrors are what a normal Ruby program are supposed to use. Generated with Ruby-doc Rdoc Generator 0.35.3. Is the following correct: class MyCustomError < StandardError attr_reader :object def initialize(message, object) super(message) @object = object end end And then: raise MyCustomError.new(anObject), "A message" to get: rescue MyCustomError => e Tenant claims they paid rent in cash and that it was stolen from a mailbox.

In those cases, we explicitly use StandardError instead: begin some.unique.situation rescue StandardError => error notify_airbrake(error) end What’s next If you found this useful, you might also enjoy: Testing HTTP Errors with Ruby Using Generated with Ruby-doc Rdoc Generator 0.35.3.