#434

backend/app/services/counts_export_projection.rb

@@ -24,6 +24,22 @@ class CountsExportProjection
       'aliases' => ['languageCode', 'name', 'scriptCode'],
       'parents' => ['id'] }.freeze
 
+  def self.default_columns(resource)
+    fields = { 'posts' => ['title', 'url', 'tags', 'parents', 'video_ms'],
+        'tags' => ['name', 'category', 'aliases', 'parents'],
+        'nico_tags' => ['name', 'linked_tags'],
+        'tag_descriptions' => ['language_code', 'body', 'source_language_code'],
+        'tag_groups' => ['name', 'description', 'members'],
+        'materials' => ['url', 'tag_id', 'source_kind'] }.fetch(resource)
+    ['resource_id', 'version_no'] + fields + ['event_type', 'user', 'created_at']
+  end
+
+  def self.default_children(resource)
+    { 'posts' => ['tags.name', 'parents.id'],
+        'tags' => ['aliases.name', 'parents.id'],
+        'tag_groups' => ['members.tagId'] }.fetch(resource, [])
+  end
+
   attr_reader :columns, :headers
 
   def initialize(params, resource:, summary:, tags:)
@@ -37,7 +53,8 @@ class CountsExportProjection
               else
                 CountsQuery::COLUMNS.fetch(resource)
               end
-    @columns = params.fetch('columns', allowed.join(',')).split(',')
+    defaults = summary ? allowed : self.class.default_columns(resource)
+    @columns = params.fetch('columns', defaults.join(',')).split(',')
     raise ArgumentError if (@columns - allowed).any? || @columns.uniq != @columns
 
     @headers = JSON.parse(params.fetch('headers', JSON.generate(@columns)))
@@ -55,7 +72,8 @@ class CountsExportProjection
 
       [path, direction]
     end
-    @selected = params.key?('children') ? params['children'].split(',').to_set : nil
+    @selected = params.key?('children') ? params['children'].split(',').to_set :
+        self.class.default_children(resource).to_set
     valid = CHILDREN.flat_map do |key, fields|
       paths(fields, key)
     end