# About string error for upload file in rails 2.1

**URL:** <https://www.ruby-forum.com/t/about-string-error-for-upload-file-in-rails-2-1/143031>\
**Category:** Rails\
**Created:** [July 14, 2008, 5:17pm UTC](https://www.ruby-forum.com/t/about-string-error-for-upload-file-in-rails-2-1/143031 "2008-07-14T17:17:44Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\
**Post date:** [July 14, 2008, 5:17pm UTC](https://www.ruby-forum.com/t/about-string-error-for-upload-file-in-rails-2-1/143031/1 "2008-07-14T17:17:44Z")

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hello:  
I have code for upload image file to server file system.This works  
in rails  
1.2.3.But in rails 2.1,it gets an error.  
The following is the important code:  
In a view:  
\<%form\_for :user,:url=\>{:action=\>“register”},:html=\>{:multipart=\>true}  
do |f|-%\>

照片 \<%=f.file\_field "file"-%\>

\<%end-%\> ############################# In a model: class User \< ActiveRecord::Base validates\_format\_of :photo,:with=\>%r{\.(jpg|png|gif)$}i, :message=\>"å›¾ç‰‡æ ¼å¼ä¸æ­£ç¡®" def file=(file\_field) File.open("#{RAILS\_ROOT}/public/images/users/#{file\_field.original\_filename}","wb+") { |i| i.write(file\_field.read)} self.photo="/images/users/"+file\_field.original\_filename end end ############################## In a controller: class LoginController \< ApplicationController def register @user=User.new(params[:user]) if params[:user]&&@user.save flash[:register]="#{@user.name}已创建" redirect\_to :action=\>"upanel" else render :action=\>"register" end end end ####################### when i submit the form,i get the following error: undefined method `original\_filename' for "":String ############ how do i make the upload code work?

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<div class="post-metadata">

**Author:** ![daociyiyou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/0ea827/32.png) [@daociyiyou](https://www.ruby-forum.com/u/daociyiyou)\
**Post date:** [July 14, 2008, 5:55pm UTC](https://www.ruby-forum.com/t/about-string-error-for-upload-file-in-rails-2-1/143031/2 "2008-07-14T17:55:53Z")

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sorry,i have resolved this problem.  
File.open("#{RAILS\_ROOT}/public/images/users/#{file\_field.original\_filename}",“wb+”)  
The “wb+” should be “wb”.