Tableau Export

app/controllers/admin/api_controller.rb

@@ -345,48 +345,6 @@ class ApiController < ApplicationController
       config.autocomplete_path = 'suggest'
     end
 
-    # Admin CSV stream of Database data
-    def tableau_export
-      headers.delete("Content-Length")
-      headers["Cache-Control"] = "no-cache"
-      headers["Content-Type"] = "text/csv"
-      headers["Content-Disposition"] = "attachment; filename=\"geoportal_tableau_export.csv\""
-      headers["X-Accel-Buffering"] = "no"
-      response.status = 200
-      self.response_body = csv_enumerator
-    end
-
-    def csv_enumerator
-      @csv_enumerator ||= Enumerator.new do |yielder|
-        yielder << CSV.generate_line([
-          "Title",
-          "Provider",
-          "Resource Class",
-          "Resource Type",
-          "Index Year",
-          "Spatial Coverage",
-          "B1G Image",
-          "ID",
-          "Download",
-          "Language"
-        ])
-        Document.find_each do |row|
-          yielder << CSV.generate_line([
-            row.title,
-            row.schema_provider_s,
-            row.gbl_resourceClass_sm&.join("|"),
-            row.gbl_resourceType_sm&.join("|"),
-            row.gbl_indexYear_im&.join("|"),
-            row.dct_spatial_sm&.join("|"),
-            row.b1g_image_ss,
-            row.geomg_id_s,
-            row.dct_references_s.find { |ref| ref.category == "download" }&.value,
-            row.dct_language_sm&.join("|")
-          ])
-        end
-      end
-    end
-
     # Administrative view of document
     # - Sidecar Image
     # - URIs
@@ -425,5 +383,11 @@ def advanced_search_facets
         end
       end
     end
+
+    # Tableau Export
+    def tableau_export
+      ExportTableauJob.perform_later(current_user)
+      head :no_content
+    end
   end
 end

app/jobs/export_tableau_job.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+require "csv"
+
+# ExportTableauJob
+class ExportTableauJob < ApplicationJob
+  queue_as :priority
+
+  def perform(current_user)
+    logger.debug("\n\n Background Job: ♞")
+    logger.debug("User: #{current_user.inspect}")
+    logger.debug("Export Service: Tableau Export")
+    logger.debug("\n\n")
+
+    # Test broadcast
+    ActionCable.server.broadcast("export_channel", {data: "Hello from Export Tableau Job!"})
+
+    # Send progress
+    file_content = ExportTableauService.call
+
+    # Write into tempfile
+    @tempfile = Tempfile.new(["export-#{Time.zone.today}", ".csv"]).tap do |file|
+      CSV.open(file, "wb") do |csv|
+        file_content.each do |row|
+          csv << row
+        end
+      end
+    end
+
+    # Create notification
+    # Message: "Download Type|Row Count|Button Label"
+    notification = ExportNotification.with(message: "CSV (Tableau)|#{ActionController::Base.helpers.number_with_delimiter(file_content.size - 1)} rows|CSV")
+
+    # Deliver notification
+    notification.deliver(current_user)
+
+    # Attach CSV file (can only attach after persisted)
+    notification.record.file.attach(io: @tempfile, filename: "geomg-export-#{Time.zone.today}.csv",
+      content_type: "text/csv")
+
+    # Update UI
+    ActionCable.server.broadcast("export_channel", {
+      data: "Notification ready!",
+      actions: [
+        {
+          method: "RefreshNotifications",
+          payload: current_user.notifications.unread.count
+        }
+      ]
+    })
+  end
+end

app/services/export_tableau_service.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+# ExportTableauService
+class ExportTableauService
+  def self.call
+    ActionCable.server.broadcast("export_channel", {progress: 0})
+
+    total = Document.count
+    count = 0
+    slice_count = 1000
+    csv_file = []
+
+    Rails.logger.debug { "\n\nExportTableauService: #{total}\n\n" }
+
+    csv_file << [
+      "Title",
+      "Provider",
+      "Resource Class",
+      "Resource Type",
+      "Index Year",
+      "Spatial Coverage",
+      "B1G Image",
+      "ID",
+      "Download",
+      "Language"
+    ]
+
+    Document.in_batches do |slice|
+      # Broadcast progress percentage
+      count += slice_count
+      progress = ((count.to_f / total) * 100).round
+      progress = 100 if progress > 100
+
+      slice.each do |row|
+        csv_file << [
+            row.title,
+            row.schema_provider_s,
+            row.gbl_resourceClass_sm&.join("|"),
+            row.gbl_resourceType_sm&.join("|"),
+            row.gbl_indexYear_im&.join("|"),
+            row.dct_spatial_sm&.join("|"),
+            row.b1g_image_ss,
+            row.geomg_id_s,
+            row.dct_references_s.find { |ref| ref.category == "download" }&.value,
+            row.dct_language_sm&.join("|")
+          ]
+      end
+
+      ActionCable.server.broadcast("export_channel", {progress: progress})
+    end
+
+    csv_file
+  end
+end