Add a 'none' text on rendering when the custom fields is empty

close #347

CustomFields/CustomFieldChoice.php

@@ -158,10 +158,18 @@ class CustomFieldChoice implements CustomFieldInterface
         return 'Choices';
     }
 
+    /**
+     * 
+     * @internal this function is able to receive data whichever is the value of "other", "multiple"
+     * @param mixed $value
+     * @param CustomField $customField
+     * @return string html representation
+     */
     public function render($value, CustomField $customField)
     {
         //extract the data. They are under a _choice key if they are stored with allow_other
-        $data = (isset($value['_choices'])) ? $value['_choices'] : $value;
+        $data = (isset($value['_choices'])) ? $value['_choices'] : 
+            is_null($value) ? array() : $value;
         
         $selected = (is_array($data)) ? $data : array($data);
         

Resources/views/CustomFieldsRendering/choice.html.twig

@@ -1,3 +1,4 @@
+{% if selected|length > 0 %}
 <ul class="custom_fields choice">
 {%- for choice in choices -%}
     {% if choice['slug'] in selected %}{%- set is_selected = true -%}{%- else -%}{%- set is_selected = false -%}{%- endif -%}
@@ -17,3 +18,6 @@
     {%- endif -%}
 {%- endfor -%}
 </ul>
+{% else %}
+    <div class="custom_fields_choice empty">{{ 'None'|trans }}</div>
+{% endif %}

Resources/views/CustomFieldsRendering/text.html.twig

@@ -1 +1 @@
-{{ text }}
+{% if text is not empty %}{{ text }}{% else %}<span class="custom_fields_text empty">{{ 'None'|trans }}</span>{% endif %}