cargar campos desde la plantilla

app/models/post.rb

@@ -15,11 +15,15 @@ require 'jekyll/utils'
 # datos y los sincroniza al momento de leer y de escribir el Document.
 class Post
   attr_accessor :content, :front_matter
-  attr_reader :post, :site, :errors, :old_post, :lang, :template
+  attr_reader :post, :site, :errors, :old_post, :lang, :template,
+    :template_fields
 
   REJECT_FROM_DATA = %w[excerpt].freeze
   # datos que no tienen que terminar en el front matter
   REJECT_FROM_FRONT_MATTER = %w[date slug draft ext].freeze
+  # datos que no traemos del template
+  REJECT_FROM_TEMPLATE = %w[date draft categories layout title ext tags date slug].freeze
+
 
   # Trabajar con posts.  Si estamos creando uno nuevo, el **site** y
   # el **front_matter** son necesarios, sino, **site** y **post**.
@@ -210,6 +214,36 @@ class Post
     @front_matter.dig(name.to_s)
   end
 
+  def template_fields
+    @template_fields ||= @template.front_matter.reject do |key, _|
+      REJECT_FROM_TEMPLATE.include? key
+    end.keys
+  end
+
+  # Obtiene el tipo de campo para la plantilla
+  def template_form_type_for(field)
+    return if (tt = @template.get_front_matter(field)).nil?
+
+    case
+    when tt == 'string'
+      type = 'text'
+    when tt == 'text'
+      type = 'text_area'
+    when tt.is_a?(Array)
+      type = 'select'
+    when tt.is_a?(FalseClass) || tt.is_a?(TrueClass)
+      type = 'check_box'
+    end
+
+    type
+  end
+
+  # Obtiene los valores posibles para el campo de la plantilla
+  def template_values_for(field)
+    return '' if %w[string text].include? @template.get_front_matter(field)
+    @template.get_front_matter(field)
+  end
+
   private
 
   # Completa el front_matter a partir de las variables de otro

app/views/posts/_form.haml

@@ -75,5 +75,22 @@
           @post.get_front_matter(:lang).try(:dig, lang)),
           { class: 'form-control select2' }
         %small.text-muted.form-text= t('posts.lang_help')
+  - @post.template_fields.each do |template|
+    - next unless type = @post.template_form_type_for(template)
+    .form-group
+      = label_tag "post_#{template}", template.humanize
+      - name = "post[#{template}]"
+      - value = @post.template_values_for(template)
+      - case type
+      - when 'text'
+        = text_field 'post', template,
+          value: value,
+          class: 'form-control'
+      - when 'text_area'
+        = text_area_tag name, value, class: 'form-control'
+      - when 'check_box'
+        = check_box_tag name, value: value, class: 'form-control'
+      - when 'select'
+        = select_tag name, value, { class: 'form-control' }
   .form-group
     = submit_tag t('posts.save'), class: 'btn btn-success'