Ruby on Rails exceptions

Ruby on Rails Exceptions: Learn how to catch errors and debug them with an example.

Ruby on Rails Exceptions

Ruby on Rails is a popular web development framework that is widely used to build applications. Because of its popularity, it is important to be aware of possible exceptions that may occur when working with Ruby on Rails. Exceptions are errors that occur during the execution of a program, and they can be used to detect and debug any errors that may be causing a program to fail.

One common exception in Ruby on Rails is the NoMethodError. This exception occurs when a method that does not exist is called in the code. It may be caused by a typo, or by a method being deprecated or removed from the program. For example, if the code attempts to call a method foobar, but there is no such method, a NoMethodError will be thrown:

def some_method
  foobar
end

some_method
# NoMethodError: undefined method `foobar' for main:Object

Another exception in Ruby on Rails is the StandardError. This exception is raised when an unexpected event occurs. This could be due to a user giving invalid input, or an unexpected value being returned from an API call. For example, if a user inputs an invalid email address, the code may raise a StandardError:

def some_method
  email = params[:email]
  raise StandardError, 'Invalid email address' if !email.valid?
end

some_method
# StandardError: Invalid email address

Exceptions are an important part of working with Ruby on Rails, as they can be used to detect and debug any errors that may be causing a program to fail. Knowing how to handle exceptions can help you ensure that your applications are running smoothly and that any errors are properly handled.