Merge pull request #10661 from mkllnk/report-download

[Hidden] Provide download link for reports generated in the background

app/controllers/admin/reports_controller.rb

@@ -2,6 +2,7 @@
 
 module Admin
   class ReportsController < Spree::Admin::BaseController
+    include ActiveStorage::SetCurrent
     include ReportsActions
     helper ReportsHelper
 
@@ -21,7 +22,7 @@ def index
     def show
       @report = report_class.new(spree_current_user, params, render: render_data?)
 
-      if report_format.present?
+      if params[:report_format].present?
         export_report
       else
         show_report
@@ -57,23 +58,30 @@ def render_data?
 
     def render_report_as(format)
       if OpenFoodNetwork::FeatureToggle.enabled?(:background_reports, spree_current_user)
-        job = ReportJob.perform_later(
-          report_class, spree_current_user, params, format
+        @blob = ReportBlob.create_for_upload_later!(report_filename)
+        ReportJob.perform_later(
+          report_class, spree_current_user, params, format, @blob
         )
         Timeout.timeout(max_wait_time) do
-          sleep 1 until job.done?
+          sleep 1 until @blob.content_stored?
         end
 
         # This result has been rendered by Rails in safe mode already.
-        job.result.html_safe # rubocop:disable Rails/OutputSafety
+        @blob.result.html_safe # rubocop:disable Rails/OutputSafety
       else
         @report.render_as(format)
       end
     end
 
     def render_timeout_error
       assign_view_data
-      @error = ".report_taking_longer"
+      if @blob
+        @error = ".report_taking_longer_html"
+        @error_url = @blob.url
+      else
+        @error = ".report_taking_longer"
+        @error_url = ""
+      end
       render "show"
     end
 

app/controllers/concerns/reports_actions.rb

@@ -56,7 +56,7 @@ def ransack_params
   end
 
   def report_format
-    params[:report_format]
+    params[:report_format].presence || "html"
   end
 
   def report_filename

app/jobs/report_job.rb

@@ -1,34 +1,10 @@
 # frozen_string_literal: true
 
-# Renders a report and saves it to a temporary file.
-class ReportJob < ActiveJob::Base
-  def perform(report_class, user, params, format)
+# Renders a report and stores it in a given blob.
+class ReportJob < ApplicationJob
+  def perform(report_class, user, params, format, blob)
     report = report_class.new(user, params, render: true)
     result = report.render_as(format)
-    write(result)
-  end
-
-  def done?
-    @done ||= File.file?(filename)
-  end
-
-  def result
-    @result ||= read_result
-  end
-
-  private
-
-  def write(result)
-    File.write(filename, result, mode: "wb")
-  end
-
-  def read_result
-    File.read(filename)
-  ensure
-    File.unlink(filename)
-  end
-
-  def filename
-    Rails.root.join("tmp/report-#{job_id}")
+    blob.store(result)
   end
 end

app/models/report_blob.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+# Stores a generated report.
+class ReportBlob < ActiveStorage::Blob
+  def self.create_for_upload_later!(filename)
+    # ActiveStorage discourages modifying a blob later but we need a blob
+    # before we know anything about the report file. It enables us to use the
+    # same blob in the controller to read the result.
+    create_before_direct_upload!(
+      filename: filename,
+      byte_size: 0,
+      checksum: "0",
+      content_type: content_type(filename),
+    ).tap do |blob|
+      ActiveStorage::PurgeJob.set(wait: 1.month).perform_later(blob)
+    end
+  end
+
+  def self.content_type(filename)
+    MIME::Types.of(filename).first&.to_s || "application/octet-stream"
+  end
+
+  def store(content)
+    io = StringIO.new(content)
+    upload(io, identify: false)
+    save!
+  end
+
+  def content_stored?
+    @content_stored ||= reload.checksum != "0"
+  end
+
+  def result
+    @result ||= download
+  end
+end

app/views/admin/reports/show.html.haml

@@ -21,5 +21,5 @@
   - if request.post? && !@error
     %button.btn-print.icon-print{ onclick: "window.print()"}= t(:report_print)
 
-= t(@error) if @error
+= t(@error, link: link_to(t(".report_link_label"), @error_url)) if @error
 = @table

config/locales/en.yml

@@ -1446,6 +1446,11 @@ en:
           Sorry, this report took too long to process.
           It may contain a lot of data or we are busy with other reports.
           You can try again later.
+        report_taking_longer_html: >
+          This report is taking longer to process.
+          It may contain a lot of data or we are busy with other reports.
+          Once it's finished, you can download it: %{link}
+        report_link_label: Download report (when available)
       revenues_by_hub:
         name: Revenues By Hub
         description: Revenues by hub

spec/jobs/report_job_spec.rb

@@ -3,34 +3,37 @@
 require 'spec_helper'
 
 describe ReportJob do
-  let(:report_args) { [report_class, user, params, format] }
+  let(:report_args) { [report_class, user, params, format, blob] }
   let(:report_class) { Reporting::Reports::UsersAndEnterprises::Base }
   let(:user) { enterprise.owner }
   let(:enterprise) { create(:enterprise) }
   let(:params) { {} }
   let(:format) { :csv }
+  let(:blob) { ReportBlob.create_for_upload_later!("report.csv") }
 
   it "generates a report" do
-    job = ReportJob.new
-    job.perform(*report_args)
-    expect_csv_report(job)
+    job = perform_enqueued_jobs(only: ReportJob) do
+      ReportJob.perform_later(*report_args)
+    end
+    expect_csv_report
   end
 
-  it "enqueues a job for asynch processing" do
+  it "enqueues a job for async processing" do
     job = ReportJob.perform_later(*report_args)
-    expect(job.done?).to eq false
+    expect(blob.content_stored?).to eq false
 
-    # This performs the job in the same process but that's good enought for
-    # testing the job code. I hope that we can rely on the job worker.
-    ActiveJob::Base.queue_adapter.perform_enqueued_jobs = true
-    job.retry_job
+    perform_enqueued_jobs(only: ReportJob)
 
-    expect(job.done?).to eq true
-    expect_csv_report(job)
+    expect(blob.content_stored?).to eq true
+    expect_csv_report
   end
 
-  def expect_csv_report(job)
-    table = CSV.parse(job.result)
+  def expect_csv_report
+    blob.reload
+    expect(blob.filename.to_s).to eq "report.csv"
+    expect(blob.content_type).to eq "text/csv"
+
+    table = CSV.parse(blob.result)
     expect(table[0][1]).to eq "Relationship"
     expect(table[1][1]).to eq "owns"
   end

spec/system/admin/reports_spec.rb

@@ -46,7 +46,7 @@
       expect(page).to have_content "EMAIL FIRST NAME"
     end
 
-    it "displays a friendly timeout message" do
+    it "displays a friendly timeout message and offers download" do
       ActiveJob::Base.queue_adapter.perform_enqueued_jobs = false
       login_as_admin
       visit admin_report_path(
@@ -57,7 +57,16 @@
 
       click_button "Go"
 
-      expect(page).to have_content "this report took too long"
+      expect(page).to have_content "report is taking longer"
+
+      perform_enqueued_jobs(only: ReportJob)
+
+      click_link "Download report"
+
+      expect(downloaded_filename).to match /customers_[0-9]+\.html/
+
+      content = File.read(downloaded_filename)
+      expect(content).to match "<th>\nFirst Name\n</th>"
     end
   end