Allow optional import fields (#865)

app/models/import.rb

@@ -148,15 +148,18 @@ class Import < ApplicationRecord
 
       name_field = Import::Field.new \
         key: "name",
-        label: "Name"
+        label: "Name",
+        is_optional: true
 
       category_field = Import::Field.new \
         key: "category",
-        label: "Category"
+        label: "Category",
+        is_optional: true
 
       tags_field = Import::Field.new \
         key: "tags",
-        label: "Tags"
+        label: "Tags",
+        is_optional: true
 
       amount_field = Import::Field.new \
         key: "amount",

app/models/import/field.rb

@@ -15,12 +15,17 @@ class Import::Field
 
   attr_reader :key, :label, :validator
 
-  def initialize(key:, label:, validator: nil)
+  def initialize(key:, label:, is_optional: false, validator: nil)
     @key = key.to_s
     @label = label
+    @is_optional = is_optional
     @validator = validator
   end
 
+  def optional?
+    @is_optional
+  end
+
   def define_validator(validator = nil, &block)
     @validator = validator || block
   end

app/views/imports/configure.html.erb

@@ -14,7 +14,8 @@
         <% @import.expected_fields.each do |field| %>
           <%= mappings.select field.key,
                               options_for_select(@import.available_headers, @import.get_selected_header_for_field(field)),
-                              label: field.label %>
+                              label: field.label,
+                              include_blank: field.optional? ? t(".optional") : false %>
         <% end %>
       <% end %>
     </div>

config/locales/views/imports/en.yml

@@ -18,6 +18,7 @@ en:
       confirm_title: Are you sure?
       invalid_csv: Please load a CSV first
       next: Next
+      optional: "(optional) No column selected"
     confirm:
       confirm_description: Preview your transactions below and check to see if there
         are any changes that are required.