excel import is not working with spreadsheet gem - ruby-on-rails-3

Question

I am using Spreadsheet gem to import excel data to database. my view is:-
<% form_for :dump, :url=>{:action=>"excel_import"}, :html => { :multipart => true } do |f| -%>
Select an Excel File :
<%= f.file_field :excel_file -%>
<%= submit_tag 'Submit' -%>
<% end -%>
and my controller is :-
require 'spreadsheet'
def excel_import
Spreadsheet.client_encoding = 'UTF-8'
book = Spreadsheet.open params[:dump][:excel_file]
sheet1 = book.worksheet 0
sheet1.each do |row|
TimeSheet.new(:ac_no => row[0]).save
end
end
Parameters:-
{"utf8"=>"✓", "authenticity_token"=>"vhyy1pzYJpM9hCdgP5AiFC1Pv0UtbpLSzStZDWiZzs8=", "dump"=>{"excel_file"=>#<ActionDispatch::Http::UploadedFile:0x9a8f5f8 #original_filename="SwipeData_DeliveryTeam_Sep12.xls", #content_type="application/vnd.ms-excel", #headers="Content-Disposition: form-data; name=\"dump[excel_file]\"; filename=\"SwipeData_DeliveryTeam_Sep12.xls\"\r\nContent-Type: application/vnd.ms-excel\r\n", #tempfile=#<File:/tmp/RackMultipart20121025-4534-n7pw14>>}, "commit"=>"Submit"}
when i am trying to upload excel file and click on submit button, I am getting error:-
can't convert ActionDispatch::Http::UploadedFile into String
I have taken the reference from blog
can anyone please tell me what is going wrong in this code.

Answer 1

I was having the exact same issue using the same blog reference you mentioned.
I was able to resolve it using this reference.
Here is your method modified to how I did mine, and mine is now working!!
require 'spreadsheet'
require 'fileutils'
require 'iconv'
def excel_import
tmp = params[:dump][:excel_file].tempfile
Spreadsheet.client_encoding = 'UTF-8'
book = Spreadsheet.open tmp.path
sheet1 = book.worksheet 0
sheet1.each do |row|
TimeSheet.new(:ac_no => row[0]).save
end
end
FileUtils.rm tmp.path
Good Luck!
Dennis