extract rendering condition

app/models/champs/drop_down_list_champ.rb

@@ -1,3 +1,7 @@
 class Champs::DropDownListChamp < Champ
   THRESHOLD_NB_OPTIONS_AS_RADIO = 5
+
+  def render_as_radios?
+    drop_down_list.enabled_non_empty_options.size <= THRESHOLD_NB_OPTIONS_AS_RADIO
+  end
 end

app/models/champs/multiple_drop_down_list_champ.rb

@@ -23,6 +23,10 @@ class Champs::MultipleDropDownListChamp < Champ
     value.present? ? selected_options.join(', ') : nil
   end
 
+  def render_as_checkboxes?
+    drop_down_list.enabled_non_empty_options.size <= THRESHOLD_NB_OPTIONS_AS_CHECKBOX
+  end
+
   private
 
   def format_before_save

app/views/shared/dossiers/editable_champs/_drop_down_list.html.haml

@@ -1,15 +1,14 @@
 - if champ.drop_down_list && champ.drop_down_list.options.any?
-  - enabled_non_empty_options = champ.drop_down_list.enabled_non_empty_options
-  - if enabled_non_empty_options.size > Champs::DropDownListChamp::THRESHOLD_NB_OPTIONS_AS_RADIO
+  - if champ.render_as_radios?
+    %fieldset.radios
+      %legend.mandatory-explanation
+        Sélectionnez une des valeurs
+      - champ.drop_down_list.enabled_non_empty_options.each do |option|
+        %label
+          = form.radio_button :value, option
+          = option
+  - else
     = form.select :value,
       champ.drop_down_list.options,
       disabled: champ.drop_down_list.disabled_options,
       required: champ.mandatory?
-  - else
-    %fieldset.radios
-      %legend.mandatory-explanation
-        Sélectionnez une des valeurs
-      - enabled_non_empty_options.each do |option|
-        %label
-          = form.radio_button :value, option
-          = option

app/views/shared/dossiers/editable_champs/_multiple_drop_down_list.html.haml

@@ -1,15 +1,15 @@
 - if champ.drop_down_list && champ.drop_down_list.options.any?
-  - enabled_non_empty_options = champ.drop_down_list.enabled_non_empty_options
-  - if enabled_non_empty_options.size > Champs::MultipleDropDownListChamp::THRESHOLD_NB_OPTIONS_AS_CHECKBOX
+  - if champ.render_as_checkboxes?
+    - champ.drop_down_list.enabled_non_empty_options.each do |option|
+      .editable-champ.editable-champ-checkbox
+        %label
+          = form.check_box :value, { multiple: true, checked: champ&.value&.include?(option) }, option, nil
+          = option
+  - else
     = form.select :value,
         champ.drop_down_list.options,
         { selected: champ.selected_options,
           disabled: champ.drop_down_list.disabled_options },
         multiple: true,
         class: 'select2'
-  - else
-    - enabled_non_empty_options.each do |option|
-      .editable-champ.editable-champ-checkbox
-        %label
-          = form.check_box :value, { multiple: true, checked: champ&.value&.include?(option) }, option, nil
-          = option
+