Workaround for 3.0 not having param_key and fix valid? on attr/sort

lib/ransack/helpers/form_helper.rb

@@ -16,6 +16,7 @@ module Ransack
           :id => options[:as] ? "#{options[:as]}_search" : "#{search.klass.to_s.underscore}_search",
           :method => :get
         }
+        options[:as] ||= 'q'
         options[:html].reverse_merge!(html_options)
         options[:builder] ||= FormBuilder
 

lib/ransack/nodes/attribute.rb

@@ -19,7 +19,7 @@ module Ransack
       end
 
       def valid?
-        attr
+        bound? && attr
       end
 
       def type

lib/ransack/nodes/bindable.rb

@@ -16,6 +16,10 @@ module Ransack
         @klass ||= context.klassify(parent)
       end
 
+      def bound?
+        attr_name.present? && parent.present?
+      end
+
       def reset_binding!
         @parent = @attr_name = @attr = @klass = nil
       end

lib/ransack/nodes/sort.rb

@@ -24,7 +24,7 @@ module Ransack
       end
 
       def valid?
-        attr
+        bound? && attr
       end
 
       def name=(name)