app/models/user.rb in devise_token_auth-0.1.19.alpha2 vs app/models/user.rb in devise_token_auth-0.1.19.alpha3

@@ -11,10 +11,14 @@
   validates_presence_of :confirm_success_url, if: Proc.new {|u| u.provider == 'email'}
 
   # only validate unique emails among email registration users
   validate :unique_email_user, on: :create
 
+  # can't set default on text fields in mysql, simulate here instead.
+  after_save :set_empty_token_hash
+  after_initialize :set_empty_token_hash
+
   def valid_token?(token, client_id='default')
     client_id ||= 'default'
 
     return false unless self.tokens[client_id]
 
@@ -128,7 +132,11 @@
   end
 
 
   def email_required?
     provider == 'email'
+  end
+
+  def set_empty_token_hash
+    self.tokens ||= {}
   end
 end