Multi-file Uploads with ColdFusion 9 in 5 Lines
Posted on Jul 15, 2009
ColdFusion 9 includes a new Flash-based page element for handling multiple file uploads. Many people have spent quite a bit of time solving this problem, but using ColdFusion 9, you could add this functionality to your site in just about 5 lines. It includes the functionality you'd expect from a multi-file upload element including things like the ability to specify a maximum number of files or a maximum file size. It's also fairly customizable using styles. So let's look at a basic example.
At its core, the new <cffileupload> tag only needs to be supplied a URL for the processing page. It also does not need to be placed inside a <cfform>. Here's my example page which will create a form element in the image on the right:
<html>
<head>
<title>CFFileUpload Example</title>
</head>
<body>
<cffileupload url="process.cfm" />
</body>
</html>
In order to handle the processing, a new action has been added to the <cffile> tag called "uploadall" which only requires the destination be supplied. Technically speaking, that's all you need on your processing page to make the form work. However, I ran into technical issues with this that the ColdFusion team helped me out with. The upload has an onComplete attribute that calls a JavaScript and passes it a json string. Even though I had not set that on my cffileupload, it seems that was causing my upload to bomb out after the first item. The lines following the cffile tag resolved that issue. This is why the title says 5 lines instead of 2 - but 5 lines for this level of functionality is still pretty amazing.
<cffile action="uploadall" destination="#expandPath('uploads')#" nameconflict="overwrite" />
<cfset str.STATUS = 200>
<cfset str.MESSAGE = "passed">
<cfoutput>#serializeJSON(str)#</cfoutput>
Obviously, in many cases you'll want to mess with more of the customization than in this very simple example. If you want to take a closer look at the customization options, the documentation for the tag can be found here.
Comments
Posted By Ben Nadel / Posted on 07/15/2009 at 10:06 AM
Posted By Dave Ferguson / Posted on 07/15/2009 at 10:12 AM
Posted By Sam Farmer / Posted on 07/15/2009 at 11:30 AM
Posted By Dan Vega / Posted on 07/15/2009 at 11:52 AM
Coldfusion tends to have that stuff already taken care of so it would be counterintuitive to require it now I think.
Posted By amclean / Posted on 07/15/2009 at 3:47 PM
Posted By Brian Rinaldi / Posted on 07/15/2009 at 4:31 PM
My security system involves checking session variables for each page to ensure the user has privileges to see the page. On loading the response page specified by the cffileupload url attribute, I can't send in the session variables, so the user cannot access the response page and the file is not uploaded.
Posted By Paul / Posted on 08/05/2009 at 4:28 PM
Posted By Tony Bentley / Posted on 10/27/2009 at 4:19 PM
Posted By Shane Heasley / Posted on 12/07/2009 at 3:38 PM
Posted By Brian Rinaldi / Posted on 12/07/2009 at 6:56 PM
Very much appreciate the answer but I use FileOpen etc. to upload files from the client - the huge advantage being that the entire file does not have to be loaded into memory. This allows for uploading of very large files and avoids the server issues that can arise if multiple large files are uploading simultaneously.
Posted By Shane Heasley / Posted on 12/07/2009 at 8:56 PM
Mea culpa - I was suffering from a serious case of public stupidity. Please ignore my last two entries. I seemed to have forgotton some basic htmil theory. UG.
Posted By Shane Heasley / Posted on 12/08/2009 at 11:17 AM
In IE8 the files upload no problem.
Anyone know how to fix it so this example works in safari and firefox?
Thanks
Posted By Ric / Posted on 06/10/2010 at 10:03 PM
Posted By Xvpulzxa / Posted on 01/31/2012 at 9:45 AM