simple framework to compute field attributes at runtime

lib/custom_wizard/field.rb

@@ -3,67 +3,59 @@
 class CustomWizard::Field
   include ActiveModel::SerializerSupport
 
-  def self.attributes
-    %i{
-      raw
-      id
-      index
-      type
-      step
-      required
-      value
-      description
-      image
-      key
-      validations
-      min_length
-      max_length
-      char_counter
-      file_types
-      format
-      limit
-      property
-      content
+  def self.attribute_map
+    {
+      raw: [],
+      id: [:serializable],
+      index: [:accessible, :serializable],
+      type: [:serializable],
+      step: [:accessible],
+      required: [:serializable],
+      value: [:serializable],
+      description: [:serializable],
+      image: [:serializable],
+      key: [],
+      validations: [:serializable],
+      min_length: [],
+      max_length: [:serializable],
+      char_counter: [:serializable],
+      file_types: [:serializable],
+      format: [:serializable],
+      limit: [:serializable],
+      property: [:serializable],
+      content: [:serializable],
+      # label is excluded so that it isn't initialized and the value
+      # returned by `label` method is used for serialization
+      label: [:excluded, :serializable]
     }
   end
 
+  def self.all_attributes
+    attribute_map.keys
+  end
+
+  def self.included_attributes
+    all_attributes - excluded_attributes
+  end
+
+  def self.type_attributes(type)
+    attribute_map.map { |attribute, props| props.include?(type.to_sym) ? attribute : nil }.compact
+  end
+
   def self.accessible_attributes
-    %i{
-      index
-      step
-    }
+    type_attributes(:accessible)
   end
 
   def self.excluded_attributes
-    %i{
-      label
-    }
+    type_attributes(:excluded)
   end
 
   def self.readonly_attributes
-    attributes - accessible_attributes - excluded_attributes
+    included_attributes - accessible_attributes
   end
 
   def self.serializable_attributes
-    %i{
-      id
-      index
-      type
-      required
-      value
-      label
-      placeholder
-      description
-      image
-      file_types
-      format
-      limit
-      property
-      content
-      validations
-      max_length
-      char_counter
-    }
+    type_attributes(:serializable)
   end
 
   attr_reader *readonly_attributes
@@ -71,7 +63,7 @@ class CustomWizard::Field
 
   def initialize(attrs)
     attrs.each do |k, v|
-      if self.singleton_class.attributes.include?(k.to_sym)
+      if self.singleton_class.included_attributes.include?(k.to_sym)
         instance_variable_set("@#{k}", v)
       end
     end