Add user and equipment CSV export

Resolves #1337
 - adds the module CsvExport to handle exporting CSV files
 - also supports exporting multiple CSVs at once in a zip file

Gemfile

@@ -28,6 +28,9 @@ gem 'net-ldap', '~> 0.13.0'
 # attachments
 gem 'paperclip', '~> 4.3.2'
 
+# for exporting multiple files
+gem 'rubyzip'
+
 # soft deletion
 gem 'permanent_records', '~> 4.1.0'
 gem 'nilify_blanks', '~> 1.2.1'

Gemfile.lock

@@ -350,6 +350,7 @@ GEM
     ruby-progressbar (1.7.5)
     rubycas-client (2.3.9)
       activesupport
+    rubyzip (1.1.6)
     safe_yaml (1.0.4)
     sass (3.4.21)
     sass-rails (5.0.4)
@@ -474,6 +475,7 @@ DEPENDENCIES
   rspec-rails (~> 3.4.0)
   rubocop (~> 0.35.1)
   ruby-progressbar (~> 1.7.5)
+  rubyzip
   sass-rails (~> 5.0.4)
   select2-rails (~> 4.0.1)
   shoulda-matchers (~> 3.0.1)

app/controllers/categories_controller.rb

@@ -5,6 +5,7 @@ class CategoriesController < ApplicationController
                 only: [:show, :edit, :update, :destroy, :deactivate]
 
   include ActivationHelper
+  include CsvExport
 
   # --------- before filter methods -------- #
   def set_current_category
@@ -18,6 +19,10 @@ def index
     else
       @categories = Category.active
     end
+    respond_to do |format|
+      format.html
+      format.zip { download_equipment_data }
+    end
   end
 
   def show

app/controllers/equipment_models_controller.rb

@@ -28,6 +28,11 @@ def index
     else
       @equipment_models = base.includes(:reservations).active
     end
+
+    respond_to do |format|
+      format.html
+      format.zip { download_equipment_data }
+    end
   end
 
   def show # rubocop:disable AbcSize, MethodLength

app/controllers/users_controller.rb

@@ -13,6 +13,7 @@ class UsersController < ApplicationController
   before_action :check_cas_auth, only: [:show, :new, :create, :edit, :update]
 
   include Autocomplete
+  include CsvExport
 
   # ------------ before filter methods ------------ #
 
@@ -32,6 +33,14 @@ def index
     else
       @users = User.active.order('username ASC')
     end
+
+    respond_to do |format|
+      format.html
+      format.csv do
+        col = %w(username first_name last_name nickname phone email affiliation)
+        download_csv(User.all, col, "users_#{Time.zone.today}")
+      end
+    end
   end
 
   def show

app/views/categories/index.html.erb

@@ -34,6 +34,7 @@
 <% if can? :manage, Category %>
   <%= link_to "New Category", new_category_path, :class => "btn btn-primary" %>
   <%= link_to "Import Categories", equip_import_page_path, :class => "btn btn-default" %>
+  <%= link_to "Export Equipment Data", categories_path(format: 'zip'), :class => "btn btn-default" %>
 <% end %>
 <% if params[:show_deleted] %>
   <%= link_to "Hide Old Categories from List", categories_path, :class => "btn btn-default" %>

app/views/equipment_items/index.html.erb

@@ -48,6 +48,7 @@
   <% else %>
     <%= link_to "New Equipment Item", new_equipment_item_path, class: 'btn btn-primary' %>
     <%= link_to "Import Equipment Item", equip_import_page_path, class: 'btn btn-default' %>
+    <%= link_to "Export Equipment Data", categories_path(format: 'zip'), :class => "btn btn-default" %>
   <% end %>
 
   <% if params[:show_deleted] %>

app/views/equipment_models/index.html.erb

@@ -9,7 +9,8 @@
     <%= link_to "View All Equipment Models", equipment_models_path, :class => 'btn btn-default' %>
   <% else %>
     <%= link_to "New Equipment Model", new_equipment_model_path, :class => "btn btn-primary" %>
-  <%= link_to "Import Equipment Models", equip_import_page_path, :class => "btn btn-default" %>
+    <%= link_to "Import Equipment Models", equip_import_page_path, :class => "btn btn-default" %>
+    <%= link_to "Export Equipment Data", categories_path(format: 'zip'), :class => "btn btn-default" %>
   <% end %>
   <% if params[:show_deleted] %>
     <% if (@category.nil?) %>

app/views/users/index.html.erb

@@ -7,6 +7,7 @@
   <%= link_to "New User", new_user_path, :class => "btn btn-primary" %>
   <% if can? :manage, User %>
     <%= link_to "Import Users", csv_import_page_path, :class => "btn btn-default" %>
+    <%= link_to "Export Users", users_path(format: 'csv'), :class => "btn btn-default" %>
   <% end %>
   <% if params[:show_banned] %>
     <%= link_to "Hide Banned Users from List", users_path, :class => "btn btn-default" %>

lib/csv_export.rb

@@ -0,0 +1,73 @@
+module CsvExport
+  require 'csv'
+  require 'zip'
+
+  PROTECTED_COLS = %w(id encrypted_password reset_password_token
+                      reset_password_sent_at)
+
+  # generates a csv from the given model data
+  # columns is optional; defaults to all columns except protected
+  def generate_csv(data, columns = [])
+    columns = data.first.attributes.keys if columns.empty?
+
+    PROTECTED_COLS.each { |col| columns.delete(col) }
+
+    CSV.generate(headers: true) do |csv|
+      csv << columns
+
+      data.each do |o|
+        csv << columns.map do |attr|
+          s = o.send(attr)
+          s.is_a?(ActiveRecord::Base) ? s.name : s
+        end
+      end
+    end
+  end
+
+  # generates a zip file containing multiple CSVs
+  # expects tables to be an array of arrays with the following format:
+  # [[objects, columns], ...]
+  # where columns is optional; defaults to all columns except protected
+  def generate_zip(tables)
+    # create the CSVs
+    csvs = tables.map { |model| generate_csv(*model) }
+
+    Zip::OutputStream.write_buffer do |stream|
+      csvs.each_with_index do |csv, i|
+        model_name = tables[i].first.first.class.name
+        stream.put_next_entry "#{model_name}_#{Time.zone.now.to_s(:number)}.csv"
+        stream.write csv
+      end
+    end.string
+  end
+
+  # downloads a csv of the given model table
+  # NOTE: this method depends on ActionController
+  def download_csv(data, columns, filename)
+    send_data(generate_csv(data, columns),
+              filename: "#{filename}_#{Time.zone.now.to_s(:number)}.csv")
+  end
+
+  # downloads a zip file containing multiple CSVs
+  # expects tables to be an array of arrays with the following format:
+  # [[objects, columns], ...]
+  # where columns is optional; defaults to all columns except protected
+  # NOTE: this method depends on ActionController
+  def download_zip(tables, filename)
+    send_data(generate_zip(tables), type: 'application/zip',
+                                    filename: "#{filename}.zip")
+  end
+
+  # NOTE: this method depends on ActionController
+  def download_equipment_data
+    categories = [Category.all, %w(name max_per_user max_checkout_length
+                                   max_renewal_times max_renewal_length
+                                   renewal_days_before_due sort_order)]
+    models = [EquipmentModel.all, %w(category name description late_fee
+                                     replacement_fee max_per_user
+                                     max_renewal_length)]
+    items = [EquipmentItem.all, %w(equipment_model name serial)]
+    download_zip([categories, models, items],
+                 "EquipmentData_#{Time.zone.now.to_s(:number)}")
+  end
+end

spec/lib/csv_export_spec.rb

@@ -0,0 +1,40 @@
+require 'spec_helper'
+include CsvExport
+
+describe CsvExport do
+  before(:all) { FactoryGirl.create(:app_config) }
+
+  MODELS = [:user, :category, :equipment_model, :equipment_item]
+  PROTECTED_COLS = %w(id encrypted_password reset_password_token
+                      reset_password_sent_at)
+
+  shared_examples 'builds a csv' do |model|
+    let(:csv) do
+      generate_csv(FactoryGirl.build_list(model, 5)).split("\n")
+    end
+
+    it 'has the appropriate length' do
+      expect(csv.size).to eq(6)
+    end
+
+    it 'has the appropriate columns' do
+      expect(csv.first.split(',')).to eq(
+        FactoryGirl.build(model).attributes.keys - PROTECTED_COLS)
+    end
+
+    it "doesn't include protected columns" do
+      PROTECTED_COLS.each do |col|
+        expect(csv.first.split(',')).not_to include(col)
+      end
+    end
+
+    it 'limits columns appropriately' do
+      cols = FactoryGirl.build(model).attributes.keys.sample(4)
+      cols.delete 'id' if cols.include? 'id'
+      csv = generate_csv(FactoryGirl.build_list(model, 5), cols).split("\n")
+      expect(csv.first.split(',')).to eq(cols)
+    end
+  end
+
+  MODELS.each { |m| it_behaves_like 'builds a csv', m }
+end