ignore_nil{} as a better alternative to try()

ignore_nil is actually short for "ignore no method error on nil", referring to the error you get if you call a method on an object that is unexpectedly nil. This can happen if you chain method calls together and one of the methods returns a nil.

ignore_nil{} will return nil if you get a NoMethodError exception on NilClass. any other exception type is reraised so that code inside ignore_nil{} blocks don't become a black- hole.

==== Examples

Without ignore_nil:

  @user && @user.address && @user.address.street

or worse:

  @user.address.street rescue nil

(worse because it catches everything! even if address doesn't have a street method!)

With ignore_nil:

  ignore_nil { @user.address.street }