Rails Raise Error And Return
Contents |
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about rails raise exception with message hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges rails raise custom error Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each
Rails Raise Error In Model
other. Join them; it only takes a minute: Sign up How do I raise an exception in Rails so it behaves like other Rails exceptions? up vote 51 down vote favorite 11 I would like to raise an exception
Rails Exception Types
so that it does the same thing a normal Rails exception does. Specially, show the exception and stack trace in development mode and show "We're sorry, but something went wrong" page in production mode. I tried the following: raise "safety_care group missing!" if group.nil? But it simply writes "ERROR signing up, group missing!" to the development.log file ruby-on-rails exception exception-handling share|improve this question asked Dec 16 '09 at 22:49 Chirag Patel 2,24762433 2 the error message you rails exceptions posted does not seem to come from this exception (it's a different message) is this really what you're seeing? –levinalex Dec 17 '09 at 0:31 add a comment| 2 Answers 2 active oldest votes up vote 84 down vote accepted You don't have to do anything special, it should just be working. When I have a fresh rails app with this controller: class FooController < ApplicationController def index raise "error" end end and go to http://127.0.0.1:3000/foo/ I am seeing the exception with a stack trace. You might not see the whole stacktrace in the console log because Rails (since 2.3) filters lines from the stack trace that come from the framework itself. See config/initializers/backtrace_silencers.rb in your Rails project share|improve this answer edited Dec 17 '09 at 0:30 answered Dec 17 '09 at 0:11 levinalex 3,8902544 2 Excellent, concise answer. –rcd Jan 5 '14 at 22:13 The skitch link (seeing the exception with a stack trace) isn't working anymore –Asaf Jun 14 at 12:47 @levinalex will this be safe in production mode to show the stacktrace? –BKSpurgeon Aug 24 at 4:18 @levinalex - thank you alex. is there any way of adding a custom string to the error message ? –BKSpurgeon Aug 24 at 4:26 add a comment| up vote 38 down vote You can do it like this: class UsersController < ApplicationController ## Exception
Web Dev @ Microsoft SEO By WooRank Books Courses Screencasts Newsletters Versioning Shop Forums Advertise Contribute Contact Us Our Story 995kSubscribers 132kFollowers 80kFollowers Ruby Article Ruby Error Handling,
Rails Standard Error
Beyond the Basics By Darko Gjorgjievski June 16, 2015 Imagine you're riding a bike. rails raise internal server error Now, imagine the designers of that bike built it so it rides smoothly only on roads without bumps and encountering one would rails raise 403 result in the entire bicycle breaking! You wouldn't want that, would you? Yet this is how thousands of software developers design their software every single day. They put error handling in as an afterthought, dealing http://stackoverflow.com/questions/1918373/how-do-i-raise-an-exception-in-rails-so-it-behaves-like-other-rails-exceptions with it only when it's inevitable. The truth is, it's not their fault. Most of the material on this subject is very basic, covering simple things like raising an error, rescuing it, different error types and…that's about it. This article will attempt to go deeper than that. I assume you're familiar with the basics of error handling (using raise, begin/rescue, what StandardError is, error inheritance). That's the only prerequisite for reading this https://www.sitepoint.com/ruby-error-handling-beyond-basics/ article. Let's begin. What Did We Do Before Raising/Handling Exceptions? Before exceptions were invented, the primary method of communication that something in the program has failed was through error return codes. As time passed, people looked at ways to clearly distinguish between what their program does and what would happen if it didn't do what it was supposed to (return codes were far from ideal for this purpose) do. Thus, the invention of language constructs like: raise rescue begin/end (Many other languages use different wording, like try/catch or throw, but the idea behind it remains the same.) There are opposing views to using exceptions and error handling in the first place. Some of these points make sense and we'll discuss them later in the article. For now, let's get you familiar with some of the ways of handling errors in Ruby that can help you manage them better. Cleanup Before Crashing Often we have no idea when our program is going to crash. What if we needed to do some cleanup operations before our program ends (due to an error)? That's where at_exit comes to the rescue: puts 'Hello' at_exit do puts 'Exiting' end raise 'error' This program will print both "Hello" and "Exiting". The code inside at_exit will execute when the program exits
users never enter incorrect data, and resources are plentiful and cheap. Well, that's about to change. Welcome to the real world! In the real world, errors happen. Good programs (and programmers) anticipate them and arrange to http://phrogz.net/programmingruby/tut_exceptions.html handle them gracefully. This isn't always as easy as it might be. Often the code that detects an error does not have the context to know what to do about it. For example, attempting to open a file that doesn't exist is acceptable in some circumstances and is a fatal error at other times. What's your file-handling module to do? The traditional approach is to use return codes. The open rails raise method returns some specific value to say it failed. This value is then propagated back through the layers of calling routines until someone wants to take responsibility for it. The problem with this approach is that managing all these error codes can be a pain. If a function calls open, then read, and finally close, and each can return an error indication, how can the function distinguish these error codes rails raise error in the value it returns to its caller? To a large extent, exceptions solve this problem. Exceptions let you package up information about an error into an object. That exception object is then propagated back up the calling stack automatically until the runtime system finds code that explicitly declares that it knows how to handle that type of exception. The Exception Class The package that contains the information about an exception is an object of class Exception, or one of class Exception's children. Ruby predefines a tidy hierarchy of exceptions, shown in Figure 8.1. As we'll see later, this hierarchy makes handling exceptions considerably easier. Figure 8.1 not available... When you need to raise an exception, you can use one of the built-in Exception classes, or you can create one of your own. If you create your own, you might want to make it a subclass of StandardError or one of its children. If you don't, your exception won't be caught by default. Every Exception has associated with it a message string and a stack backtrace. If you define your own exceptions, you can add additional information. Handling Exceptions Our jukebox downloads songs from the Internet using a TCP socket. The basic code is simple: opFile =