Railscasts＃396不适用于导入Excel工作表
我使用Railscasts来创build上传CSV和Excel文件的function。 导入CSV文件运行良好，但是当我使用Ryan的代码导入使用Roo gem的Excel工作表时，会引发错误：
InventoryItemsController中的TypeError＃import“无法将nil转换为哈希”
这是控制器中的导入方法：
def import InventoryItem.import(params[:file]) redirect_to inventory_items_path, notice: "Inventory Items imported successfully!" end 我在application.rb文件中require 'roo'以及require 'csv'
模型中的代码是：
def self.import(file) spreadsheet = open_spreadsheet(file) header = spreadsheet.row(1) (2..spreadsheet.last_row).each do |i| row = Hash[[header, spreadsheet.row(i)].transpose] inventory_item = InventoryItem.find_by_inventory_id(row["inventory_id"]) || new inventory_item.attributes = row.to_hash #.slice(*accessible_attributes) inventory_item.save! end end def self.open_spreadsheet(file) binding.pry case File.extname(file.original_filename) when ".csv" then CSV.new(file.path, nil) when ".xls" then Excel.new(file.path, nil) when ".xlsx" then Excelx.new(file.path, nil) else raise "Unknown file type: #{file.original_filename}" end end
所以，我坚持的是，CSV文件成功导入以下代码：
def self.import(file) CSV.foreach(file.path, headers: true) do |row| inventory_item = InventoryItem.find_by_inventory_id(row["inventory_id"]) || new inventory_item.attributes = row.to_hash #.slice(*accessible_attributes) inventory_item.save! end end
但从上面使用代码（self.import with self.open_spreadsheet）时，它不起作用。
这是使用Roogem，我认为有一些重写要做的方法，但我不太确定…我被困在接下来做什么来得到这个工作。
任何帮助将非常感激！ 谢谢！
完整的错误痕迹：
TypeError (can't convert nil into Hash) /Users/marcacyr/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/csv.rb:1565:in `merge' /Users/marcacyr/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/csv.rb:1565:in `initialize' app/models/inventory_item.rb:27:in `new' app/models/inventory_item.rb:27:in `open_spreadsheet' app/models/inventory_item.rb:14:in `import' app/controllers/inventory_items_controller.rb:85:in `import' actionpack (3.0.9) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (3.0.9) lib/abstract_controller/base.rb:150:in `process_action' actionpack (3.0.9) lib/action_controller/metal/rendering.rb:11:in `process_action' actionpack (3.0.9) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (3.0.9) lib/active_support/callbacks.rb:476:in `_run__2908593346646715497__process_action__1677791179652643815__callbacks' activesupport (3.0.9) lib/active_support/callbacks.rb:410:in `_run_process_action_callbacks' activesupport (3.0.9) lib/active_support/callbacks.rb:94:in `run_callbacks' actionpack (3.0.9) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (3.0.9) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' activesupport (3.0.9) lib/active_support/notifications.rb:52:in `block in instrument' activesupport (3.0.9) lib/active_support/notifications/instrumenter.rb:21:in `instrument' activesupport (3.0.9) lib/active_support/notifications.rb:52:in `instrument' actionpack (3.0.9) lib/action_controller/metal/instrumentation.rb:29:in `process_action' actionpack (3.0.9) lib/action_controller/metal/rescue.rb:17:in `process_action' newrelic_rpm (3.6.1.88) lib/new_relic/agent/instrumentation/rails3/action_controller.rb:38:in `block in process_action' newrelic_rpm (3.6.1.88) lib/new_relic/agent/instrumentation/controller_instrumentation.rb:318:in `perform_action_with_newrelic_trace' newrelic_rpm (3.6.1.88) lib/new_relic/agent/instrumentation/rails3/action_controller.rb:37:in `process_action' actionpack (3.0.9) lib/abstract_controller/base.rb:119:in `process' actionpack (3.0.9) lib/abstract_controller/rendering.rb:41:in `process' rack-mini-profiler (0.1.31) Ruby/lib/mini_profiler/profiling_methods.rb:108:in `block in profile_method' actionpack (3.0.9) lib/action_controller/metal.rb:138:in `dispatch' actionpack (3.0.9) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' actionpack (3.0.9) lib/action_controller/metal.rb:178:in `block in action' actionpack (3.0.9) lib/action_dispatch/routing/route_set.rb:62:in `call' actionpack (3.0.9) lib/action_dispatch/routing/route_set.rb:62:in `dispatch' actionpack (3.0.9) lib/action_dispatch/routing/route_set.rb:27:in `call' rack-mount (0.6.14) lib/rack/mount/route_set.rb:148:in `block in call' rack-mount (0.6.14) lib/rack/mount/code_generation.rb:93:in `block in recognize' rack-mount (0.6.14) lib/rack/mount/code_generation.rb:68:in `optimized_each' rack-mount (0.6.14) lib/rack/mount/code_generation.rb:92:in `recognize' rack-mount (0.6.14) lib/rack/mount/route_set.rb:139:in `call' actionpack (3.0.9) lib/action_dispatch/routing/route_set.rb:493:in `call' newrelic_rpm (3.6.1.88) lib/new_relic/rack/error_collector.rb:12:in `call' newrelic_rpm (3.6.1.88) lib/new_relic/rack/agent_hooks.rb:18:in `call' newrelic_rpm (3.6.1.88) lib/new_relic/rack/browser_monitoring.rb:16:in `call' newrelic_rpm (3.6.1.88) lib/new_relic/rack/developer_mode.rb:28:in `call' meta_request (0.2.7) lib/meta_request/middlewares/app_request_handler.rb:13:in `call' rack-contrib (1.1.0) lib/rack/contrib/response_headers.rb:17:in `call' meta_request (0.2.7) lib/meta_request/middlewares/headers.rb:16:in `call' meta_request (0.2.7) lib/meta_request/middlewares/meta_request_handler.rb:13:in `call' meta_request (0.2.7) lib/meta_request/middlewares/request_id.rb:24:in `call' bullet (4.6.0) lib/bullet/rack.rb:10:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/head.rb:14:in `call' rack (1.2.8) lib/rack/methodoverride.rb:24:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/params_parser.rb:21:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/flash.rb:182:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/session/abstract_store.rb:149:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/cookies.rb:302:in `call' activerecord (3.0.9) lib/active_record/query_cache.rb:32:in `block in call' activerecord (3.0.9) lib/active_record/connection_adapters/abstract/query_cache.rb:28:in `cache' activerecord (3.0.9) lib/active_record/query_cache.rb:12:in `cache' activerecord (3.0.9) lib/active_record/query_cache.rb:31:in `call' activerecord (3.0.9) lib/active_record/connection_adapters/abstract/connection_pool.rb:354:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/callbacks.rb:46:in `block in call' activesupport (3.0.9) lib/active_support/callbacks.rb:416:in `_run_call_callbacks' actionpack (3.0.9) lib/action_dispatch/middleware/callbacks.rb:44:in `call' rack (1.2.8) lib/rack/sendfile.rb:106:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/remote_ip.rb:48:in `call' airbrake (3.1.12) lib/airbrake/rails/middleware.rb:13:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/show_exceptions.rb:47:in `call' railties (3.0.9) lib/rails/rack/logger.rb:13:in `call' rack (1.2.8) lib/rack/runtime.rb:17:in `call' activesupport (3.0.9) lib/active_support/cache/strategy/local_cache.rb:72:in `call' rack (1.2.8) lib/rack/lock.rb:13:in `block in call' <internal:prelude>:10:in `synchronize' rack (1.2.8) lib/rack/lock.rb:13:in `call' actionpack (3.0.9) lib/action_dispatch/middleware/static.rb:30:in `call' rack-mini-profiler (0.1.31) Ruby/lib/mini_profiler/profiler.rb:278:in `call' airbrake (3.1.12) lib/airbrake/user_informer.rb:16:in `_call' airbrake (3.1.12) lib/airbrake/user_informer.rb:12:in `call' railties (3.0.9) lib/rails/application.rb:168:in `call' railties (3.0.9) lib/rails/application.rb:77:in `method_missing' railties (3.0.9) lib/rails/rack/log_tailer.rb:14:in `call' rack (1.2.8) lib/rack/content_length.rb:13:in `call' rack (1.2.8) lib/rack/handler/webrick.rb:52:in `service' /Users/marcacyr/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service' /Users/marcacyr/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run' /Users/marcacyr/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
该错误指向您尝试创build新CSV ，并且该错误告诉您确切的错误。 它不能将nil转换成散列。 你应该使用CSV.new(file.path, {})或CSV.new(file.path)代替CSV.new(file.path, nil) CSV.new(file.path) 。
对于Rails 4和Ruby 2，当遵循Railscast＃396时，出现“500 Internal Server Error”错误
我现在的解决scheme是使用：
Roo::CSV.new(file.path, csv_options: {col_sep: ";"})
代替
Csv.new(file.path, nil, :ignore)