我在 Heroku 服务器上上传文件时遇到问题。（也非常感谢使用rails做此类事情的正确方法的提示 - 我在RoR中非常新）。
所有这些代码都是关于上传一些 CSV 文件，然后允许用户调整几个设置，然后解析文件。这通常在本地主机上工作（有几次我在会话中存储的值遇到问题），但在 Heroku 上它总是在上传时死掉。
在其中一个社区问题中写道，Heroku 仅在单个实例运行期间存储文件，但我在 Heroku 的文档中仍然找不到任何关于此的内容。我应该在上传后立即将文件数据存储在数据库中，所以在这种情况下它总是可用的吗？缺点 - 文件可能非常大，大约 10-20Mb，看起来不太好。
Heroku 日志说：
2012-05-21T19:27:20+00:00 app[web.1]: Started POST "/products/upload" for 46.119
.175.140 at 2012-05-21 19:27:20 +0000
2012-05-21T19:27:20+00:00 app[web.1]: Processing by ProductsController#upload
as HTML
2012-05-21T19:27:20+00:00 app[web.1]: Parameters: {"utf8"=>"тЬУ", "authenticit
y_token"=>"aqJFg3aqENfxS2lKCE4o4txxkZTJgPx36SZ7r3nyZBw=", "upload"=>{"my_file"=>
#<ActionDispatch::Http::UploadedFile:0x000000053af020 @original_filename="marina
-AutoPalmaPriceList_2011-07-30.txt", @content_type="text/plain", @headers="Conte
nt-Disposition: form-data; name=\"upload[my_file]\"; filename=\"marina-AutoPalma
PriceList_2011-07-30.txt\"\r\nContent-Type: text/plain\r\n", @tempfile=#<File:/t
mp/RackMultipart20120521-1-10g8xmx>>}, "commit"=>"Upload"}
2012-05-21T19:27:20+00:00 app[web.1]:
2012-05-21T19:27:20+00:00 app[web.1]: LoadError (no such file to load -- CSV):
2012-05-21T19:27:20+00:00 app[web.1]: app/controllers/products_controller.rb:8
2:in `upload'
2012-05-21T19:27:20+00:00 app[web.1]:
2012-05-21T19:27:20+00:00 app[web.1]:
2012-05-21T19:27:20+00:00 app[web.1]: cache: [POST /products/upload] invalidate,
pass
代码本身：
产品控制器：
def import
respond_to do |format|
format.html
end
end
def import_adjust
case params[:commit]
when "Adjust"
@col_default = params[:col_data]
#abort @col_default.to_yaml
#update csv reader with form data, restore filters from params
when "Complete"
#all ok, read the whole file
#abort params.to_yaml
redirect_to import_complete
else
@col_default = nil
end
#read first part of the file
@tmp = session[:import_file]
@csv = []
source = CSV.open @tmp, {col_sep: ";"}
5.times do
line = source.readline
if line.size>0
@line_size = line.size
@csv.push line
end
end
#generate a selection array
#selection = select_tag 'col_data[]', options_for_select([['name','name'], ['brand','brand'], ['delivery_time','delivery_time'], ['price','price']])
#@csv = [selection * line_size] + @csv
end
def import_complete
#remove all items
#todo check products with line items will not be destroyed.
Product.destroy_all
#abort params.to_yaml
map = {}
cnt = 0
#todo check for params count.
params[:col_data].each do |val|
map[cnt] = val if val != 'ignore'
cnt += 1
end
source = CSV.open session[:import_file], {col_sep: ';'}
source.each do |row|
cnt += 1
if row.size > 0
item = Product.new
map.each do |col, attr|
item[attr] = row[col]
end
item[:provider_id] = params[:adjust][:provider]
item.save
#abort item.to_yaml
end
end
#abort map.to_yaml
#todo response needed.
end
def upload
require 'CSV' #looks like I dont need this in fact.
@tmp = params[:upload][:my_file].path #tempfile
@csv = []
#source = CSV.open @tmp, {col_sep: ";"}
session[:import_file] = params[:upload][:my_file].path
respond_to do |format|
format.html { redirect_to action: 'import_adjust' }
end
end
上传.html.erb：
<h1>Uploaded</h1>
<%= @tmp %>
<% @csv.each do |val| %>
<%= val %>
<% end %>
_form_import.html.erb：
<%= form_for :upload, :html => {:multipart => true}, :url => {action: "upload"} do |f| %>
<%= f.file_field :my_file %>
<%= f.submit "Upload" %>
<% end %>
import_adjust.html.erb：
<h1>New product</h1>
<%= form_for :adjust, :url => {action: "import_adjust"} do |f| %>
<% if @csv %>
<table>
<tr>
<% @line_size.times do |cnt| %>
<td>
<%= select_tag 'col_data[]',
options_for_select([
['--ignore--', 'ignore'],
['name','name'],
['brand','brand'],
['delivery_time','delivery_time'],
['price','price']
], @col_default!=nil ? @col_default[cnt] : nil) %>
</td>
<% end %>
</tr>
<% @csv.each do |val| %>
<tr>
<% val.each do |cell| %>
<td>
<%= cell %>
</td>
<% end %>
</tr>
<% end %>
</table>
<% end %>
<%= f.label :delimiter, 'Разделитель' %>
<%= f.text_field :delimiter %>
<br>
<%= f.label :provider, 'Поставщик' %>
<%#todo default empty option needed! Human mistakes warning! %>
<%= f.select :provider, Provider.all.collect { |item| [item.name, item.id] } %>
<br>
<%= f.label :delimiter, 'Разделитель' %>
<%= f.text_field :delimiter %>
<br>
<%# Adjust for proceed adjusting or Complete for parsing %>
<%= f.submit "Adjust" %>
<%= f.submit "Complete" %>
<% end %>
<%= link_to 'Back', products_path %>