Rails 'button_to' 不适用于 'send_file' 方法

Question

在视图中，假设我有一个按钮。如果我点击它，它应该会触发文件下载。

在我看来，我有：

<%= link_to 'Download File', download_file_home_path %>

在 routes.rb 中

resources :homes, only: [:update] do
  member do
    get 'download_file'
  end
end

在 home_controller.rb 中

def download_file
  send_file "path/to/file.pdf"
end

当我点击链接时，一切正常并触发下载。但我需要一个按钮而不是链接。当我使用button_to 方法时，它失败了，我得到以下错误：

ActionController::RoutingError (No route matches [POST] "/source_machines/4/download_report"):
  actionpack (4.2.5) lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  actionpack (4.2.5) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  railties (4.2.5) lib/rails/rack/logger.rb:38:in `call_app'
  railties (4.2.5) lib/rails/rack/logger.rb:20:in `block in call'
  activesupport (4.2.5) lib/active_support/tagged_logging.rb:68:in `block in tagged'
  activesupport (4.2.5) lib/active_support/tagged_logging.rb:26:in `tagged'
  activesupport (4.2.5) lib/active_support/tagged_logging.rb:68:in `tagged'
  railties (4.2.5) lib/rails/rack/logger.rb:20:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  actionpack (4.2.5) lib/action_dispatch/middleware/request_id.rb:21:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack (1.6.4) lib/rack/runtime.rb:18:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  activesupport (4.2.5) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack-rewrite (1.5.1) lib/rack/rewrite.rb:24:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack (1.6.4) lib/rack/lock.rb:17:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  railties (4.2.5) lib/rails/engine.rb:518:in `call'
  railties (4.2.5) lib/rails/application.rb:165:in `call'
  railties (4.2.5) lib/rails/railtie.rb:194:in `public_send'
  railties (4.2.5) lib/rails/railtie.rb:194:in `method_missing'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack (1.6.4) lib/rack/deflater.rb:35:in `call'
  newrelic_rpm (3.16.1.320) lib/new_relic/agent/instrumentation/middleware_tracing.rb:96:in `call'
  rack (1.6.4) lib/rack/content_length.rb:15:in `call'
  puma (3.6.0) lib/puma/configuration.rb:225:in `call'
  puma (3.6.0) lib/puma/server.rb:578:in `handle_request'
  puma (3.6.0) lib/puma/server.rb:415:in `process_client'
  puma (3.6.0) lib/puma/server.rb:275:in `block in run'
  puma (3.6.0) lib/puma/thread_pool.rb:116:in `call'
  puma (3.6.0) lib/puma/thread_pool.rb:116:in `block in spawn_thread'
  logging (2.1.0) lib/logging/diagnostic_context.rb:450:in `call'
  logging (2.1.0) lib/logging/diagnostic_context.rb:450:in `block in create_with_logging_context'

我的问题是为什么它适用于link_to 而不适用于button_to 方法，我该怎么做才能使其适用于button_to

Answer 1

好的，试试看：

<%= button_to 'your_button_name', your_path, method: 'get' %>

Answer 2

根据@prashant 的评论，

这是因为您的操作路由是为 GET 请求创建的，并且您的链接正在发送 GET 请求，因此它可以正常工作。但是 button_to 将请求作为 POST 请求发送，与任何路由都不匹配。

所以添加method: 'get' 解决了这个问题。

视图应如下所示：

<%= button_to 'Download Report', download_file_home_path, method: 'get' %>