si la tabla de datos es un array, tenemos que poder agregar filas

app/views/posts/template_field/_check_box.haml

@@ -1,5 +1,4 @@
-- root, field_name = field_name_for_post(name)
-= hidden_field root, field_name, value: 'false'
+= hidden_field_tag field_name_for_post_as_string(name), value: 'false'
 = check_box_tag field_name_for_post_as_string(name),
   'true',
   value == 'true',

app/views/posts/template_field/_table.haml

@@ -4,12 +4,22 @@
     %tr
       - template.nested_fields.each do |nf|
         %td= nf.help || nf.human
+      %td
+        - if template.array?
+          %button.btn.btn-success= t('posts.row.add')
   %tbody
     %tr
       - template.nested_fields.each do |nf|
         - value = @post.new? ? nf.values : @post.get_front_matter(template)[nf]
+        -# Si el template es un array, quiere decir que esperamos un array de hashes.
+        -# El 0 luego es reemplazado por un id temporal
+        - if template.array?
+          - name = [template.key, '', nf.key]
+        - else
+          - name = [template.key, nf.key]
         %td= render "posts/template_field/#{nf.type}",
           template: nf,
-          name: [template.key, nf.key],
+          name: name,
           value: value
-      %td= fa_icon 'close', title: 'Eliminar'
+      - if template.array?
+        %td= fa_icon 'close', title: t('posts.row.del')

app/views/posts/template_field/_text.haml

@@ -1,7 +1,6 @@
 -# Si el campo está anidado, la raíz del atributo name tiene que
 -# contener los demás elementos del template superior
-- root, field_name = field_name_for_post(name)
-= text_field root, field_name,
-  value: local_assigns[:value],
+= text_field_tag field_name_for_post_as_string(name),
+  value,
   class: 'form-control',
   required: template.required?