Upload form enctype

[skyagh]

Why does a upload form requires the enctype to be set to multipart/form-data?

[~n[EO]n~]

ENCTYPE determines how the form data is encoded. Whenever data is transmitted from one place to another, there needs to be an agreed upon means of representing that data. Music is translated into written music notation, English is written using letters and punctuation. Similarly, there needs to be an agreed on way of presenting the form data so it's clear that, for example, there is a field called "email" and its value is "abc@xyz.com".

 

What is Actually Sent with ENCTYPE

The browser encodes form data very differently for application/x-www-form-urlencoded and "multipart/form-data".

 

POST /cgi-bin/maillist.cgi HTTP/1.0

Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*

Referer: http://www.idocs.com/tags/foo.html

Accept-Language: en

Content-type: multipart/form-data; boundary=---------------------------7cd1d6371ec

UA-pixels: 640x480

UA-color: color8

UA-OS: Windows 95

UA-CPU: x86

User-Agent: Mozilla/2.0 (compatible; MSIE 3.0; Windows 95)

Host: 10.10.10.20

Content-Length: 25852

Pragma: No-Cache

Connection: Keep-Alive

 

-----------------------------7cd1d6371ec

Content-Disposition: form-data; name="realname"

 

Steve Johnson

-----------------------------7cd1d6371ec

Content-Disposition: form-data; name="email"

 

steevo@idocs.com

-----------------------------7cd1d6371ec

Content-Disposition: form-data; name="MyPicture"; filename="C:\My Documents\Java\misc\pics\steve.jpg"

Content-Type: image/jpeg

 

 

http://www.htmlcodetutorial.com/forms/form_enctype.html