What are the different exception classes in Rails?

What are the different exception classes in Rails?

In Rails, exception classes are used to handle errors. Some common ones include ActiveRecord::RecordNotFound, ActionController::RoutingError, and ActiveRecord::RecordInvalid.

Can you explain what ActiveRecord::RecordNotFound does?

ActiveRecord::RecordNotFound is raised when a record is not found in the database. It typically occurs when you try to find a record by its ID and it doesn't exist.

How can I rescue from this exception?

You can rescue from ActiveRecord::RecordNotFound by using a begin-rescue block. For example:

begin
  user = User.find(params[:id])
rescue ActiveRecord::RecordNotFound
  redirect_to users_path, alert: 'User not found.'
end

Are there any other common exceptions I should know about?

Yes, other common exceptions include ActionController::InvalidAuthenticityToken, which occurs when the CSRF token is invalid, and ActiveRecord::RecordInvalid, which is raised when validations fail.