For anyone who has built a web page that has uploaded and sent files (such as sending resumes to the Human Resources department of a law firm), you probably know that one of the most frustrating things about sending mail from ColdFusion is that the mail doesn't get sent out immediately; it gets spooled. This means that your mail file sits in a directory until the mail service finds it and sends it out. Since sending mail is very much a "set it and forget it" function, the point of friction here is not obvious at first. It does, however, become very clear the second you want to delete the file you just sent out as an attachment.
When a user uploads a file purely for an email attachment, most likely, unless you have a fairly complex system, you don't want to keep that file on your server; so, after they upload it, you send out your mail and then delete the file. Then, you find out that your emails aren't being sent. It turns out, since the emails are spooled, you actually deleted the attachment file before the email was processed, which of course threw an error which you probably didn't see, because your ColdFusion page seemed to work just fine.
To get over this, we have learned to turn off spooling on emails that have "temporary" attachments, right? This works because the email is processed the second the CFMail tag is finished, in a SYNCHronous manor. This allows the code directly after the CFMail tag to assume the email has been completely sent out and therefore can execute without any precautions. But this never feels good; I hate the idea of forcing the mail service to act in a way that it is not optimized to do.
This is why the new Remove attribute of the CFMailParam tag (introduced by the ColdFusion 8.0.1 updater) is so exciting! It allows you to flag email attachments for deletion without you having to do anything or worry about spooling! The ColdFusion server takes care of all of this for you. Zero friction. All you have to do is include remove="true" on any CFMailParam file that needs to be deleted after the email has been processed.
Let's take a look at a really simple example (focusing on the new CFMailParam attribute, not on any proper form validation or file handling):
<!--- Param form values. ---> <cfparam name="FORM.email" type="string" default="" /> <cfparam name="FORM.file" type="string" default="" /> <!--- Check to see if the form has been submitted. For the purposes of this very simple demo, we are going to do this by seeing if the form data is valid. ---> <cfif ( IsValid( "email", FORM.email ) AND Len( FORM.file ) )> <!--- Upload the file to the upload directory. ---> <cffile action="upload" filefield="file" destination="#ExpandPath( './' )#" nameconflict="makeunique" /> <!--- Send email. ---> <cfmail to="#FORM.email#" from="firstname.lastname@example.org" subject="File Send by #FORM.email#" type="html"> <p> The following file has been upload and sent from the Kinky Solutions CFMailParam Remove Attribute demo page. <em>(Please see attached file)</em>. </p> <!--- Attach the file. When doing this, use the remove attribute so that the file is deleted from the server after the mail has been sent. ---> <cfmailparam file="#CFFILE.ServerDirectory#/#CFFILE.ServerFile#" remove="true" /> </cfmail> </cfif> <cfoutput> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <title>CFMailParam Remove Attribute Demo</title> </head> <body> <h1> CFMailParam Remove Attribute Demo </h1> <form action="#CGI.script_name#" method="post" enctype="multipart/form-data"> <label> Email Address:<br /> <input type="text" name="email" size="40" /> </label> <br /> <br /> <input type="file" name="file" size="60" /> <br /> <br /> <input type="submit" value="Send File" /> </form> </body> </html> </cfoutput>
Here, I am just getting an email address and a file for attachment and sending it out. Notice that my CFMail tag makes no use of the SpoolEnable attribute. This is because the CFMailParam tag is using the new Remove attribute which will take care of the file system clean up for us after the mail has been sent.
This is awesome. Here's a great example of where a seemingly small change will end up making such a huge impact on coding effort.
As you are testing this new feature, you can actually see it work in real time. After I uploaded the file, one_curvey_line_up.jpg (and yes, I realized I misspelled curvy, don't rub it in), here is what my file system looks like:
I uploaded the image to the current directory and there it is - after the ColdFusion page has been processed but the email itself has not been sent.
Then, I jumped over to my email and refreshed the screen. Still nothing, and indeed, switching back to my file server, I could see that the image file was still there. But then, a few seconds later, the email showed up in my account:
Now that the mail file has been processed, I once again jumped back over to my file server to see that the image file had been successfully removed without me having to do any additional work:
Woohoo! I hope I am not the only one who sees just how exciting this is. This is going to make life much much easier.
Want to use code from this post? Check out the license.