Module: FriendlyId::ObjectUtils

Defined in:
lib/friendly_id/object_utils.rb

Overview

Utility methods for determining whether any object is a friendly id.

Monkey-patching Object is a somewhat extreme measure not to be taken lightly by libraries, but in this case I decided to do it because to me, it feels cleaner than adding a module method to FriendlyId. I’ve given the methods names that unambigously refer to the library of their origin, which should be sufficient to avoid conflicts with other libraries.

Instance Method Summary collapse

Instance Method Details

#friendly_id? ⇒ Boolean

True is the id is definitely friendly, false if definitely unfriendly, else nil.

An object is considired “definitely unfriendly” if its class is or inherits from ActiveRecord::Base, Array, Hash, NilClass, Numeric, or Symbol.

An object is considered “definitely friendly” if it responds to to_i, and its value when cast to an integer and then back to a string is different from its value when merely cast to a string:

123.friendly_id?                  #=> false
:id.friendly_id?                  #=> false
{:name => 'joe'}.friendly_id?     #=> false
['name = ?', 'joe'].friendly_id?  #=> false
nil.friendly_id?                  #=> false
"123".friendly_id?                #=> nil
"abc123".friendly_id?             #=> true

Returns:

  • (Boolean) 


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# File 'lib/friendly_id/object_utils.rb', line 29

def friendly_id?
  # Considered unfriendly if this is an instance of an unfriendly class or
  # one of its descendants.
  unfriendly_classes = [ActiveRecord::Base, Array, Hash, NilClass, Numeric,
                        Symbol, TrueClass, FalseClass]

  if unfriendly_classes.detect {|klass| self.class <= klass}
    false
  elsif respond_to?(:to_i) && to_i.to_s != to_s
    true
  end
end

#unfriendly_id? ⇒ Boolean

True if the id is definitely unfriendly, false if definitely friendly, else nil.

Returns:

  • (Boolean) 


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# File 'lib/friendly_id/object_utils.rb', line 44

def unfriendly_id?
  val = friendly_id? ; !val unless val.nil?
end