How does one use rescue in Rails without the begin and end block.

Question

I know of the standard technique of having a begin rescue end

How does one just use the rescue block on its own.

How does it work and how does it know which code is being monitored?

Answer 1

A method "def" can serve as a "begin" statement:

def foo
  ...
rescue
  ...
end

Answer 2

You can also rescue inline:

1 + "str" rescue "EXCEPTION!"

will print out "EXCEPTION!" since 'String can't be coerced into Fixnum'

Answer 3

I'm using the def / rescue combination a lot with ActiveRecord validations:

def create
   @person = Person.new(params[:person])
   @person.save!
   redirect_to @person
rescue ActiveRecord::RecordInvalid
   render :action => :new
end

I think this is very lean code!