在延迟的 sinatra 请求中使用 send_file答案

【问题标题】：using send_file in deferred sinatra request在延迟的 sinatra 请求中使用 send_file
【发布时间】：2012-08-26 19:14:56
【问题描述】：

我正在尝试在异步 sinatra 请求期间返回一个文件，如下所示：

aget "/test" do
  if(File.exists?("test.tar"))
    send_file("test.tar", :filename => "test.tar", :type => "application/octet-stream")
    return
  end

  EM.defer(proc{
      # create test.tar
    },
    proc{ |r|
      send_file("test.tar", :filename => "test.tar", :type => "application/octet-stream")
    })

但是，当我这样做时，似乎出现了错误：

wrong number of arguments (0 for 1)
file: file.rb
location: call
line: 29

回溯：

/var/lib/gems/1.9.1/gems/rack-1.4.1/lib/rack/file.rb in call
    def call(env)
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in block in body
    response.body = Array(async_handle_exception {response.body.call})
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in async_handle_exception
    yield
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in body
    response.body = Array(async_handle_exception {response.body.call})
/var/lib/gems/1.9.1/gems/sinatra-1.3.2/lib/sinatra/base.rb in invoke
    body(res.pop)
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in block in async_catch_execute
    invoke { halt h }
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in async_handle_exception
    yield
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in async_catch_execute
    async_handle_exception do
/var/lib/gems/1.9.1/gems/async_sinatra-1.0.0/lib/sinatra/async.rb in block in async_schedule
    native_async_schedule { async_catch_execute(&b) }
/var/lib/gems/1.9.1/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb in call
    end.each { |j| j.call }
/var/lib/gems/1.9.1/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb in block in run_deferred_callbacks
    end.each { |j| j.call }
/var/lib/gems/1.9.1/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb in each
    @next_tick_mutex.synchronize do
/var/lib/gems/1.9.1/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb in run_deferred_callbacks
    @next_tick_mutex.synchronize do
/var/lib/gems/1.9.1/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb in run_machine
    run_machine
/var/lib/gems/1.9.1/gems/eventmachine-1.0.0.beta.4/lib/eventmachine.rb in run
    run_machine
/var/lib/gems/1.9.1/gems/thin-1.3.1/lib/thin/backends/base.rb in start
    EventMachine.run(&starter)
/var/lib/gems/1.9.1/gems/thin-1.3.1/lib/thin/server.rb in start
    @backend.start
/var/lib/gems/1.9.1/gems/rack-1.4.1/lib/rack/handler/thin.rb in run
    server.start
/var/lib/gems/1.9.1/gems/sinatra-1.3.2/lib/sinatra/base.rb in run!
    handler.run self, :Host => bind, :Port => port do |server|
/var/lib/gems/1.9.1/gems/sinatra-1.3.2/lib/sinatra/main.rb in block in <module:Sinatra>
    at_exit { Application.run! if $!.nil? && Application.run? }


end

【问题讨论】：

为什么不在if 语句中包含EM 块并删除对send_file 的第一次调用？
第 29 行的代码是什么
我也确定这是一个错字，但你有 get 而不是 get in your code 的第一行

标签： ruby sinatra

【解决方案1】：

您收到的错误是因为您使用的函数需要 1 个参数并且您没有提供任何参数。如果您可以向我们展示第 29 行的代码，我或有人可以为您指出。

【讨论】：