Picture Preview page in coldfusion - coldfusion

Question

I know how to upload an image file to a server and show the image file to a page.
But what if I want a preview on a confirmation page?
I can probably generate a temp file that isn't saved in the database but is a file in a physical location, but what if I decided to hit the "no" button. How would this temp file be deleted?
The code below shrinks the image and shows it on the page. But it also creates an image within the directory, that will stay there after I hit OK or NO. The NO is button, while the OK naturally is a submit.
<!--- Make Temp Image as Preview --->
<cfset mediapath = expandpath('../images/about')>
<cfif structKeyExists(form,"image") and len(form.image)>
<cffile action="upload"
filefield="image"
destination="#MediaPath#"
nameconflict="makeunique">
<cfimage name="uploadedImage"
source="#MediaPath#/#file.serverFile#" >
<cfset imagesize = 320>
<cfif uploadedImage.width gt uploadedImage.height>
<cfset percentage = (imagesize / uploadedImage.width)>
<cfelse>
<cfset percentage = (imagesize / uploadedImage.height)>
</cfif>
<cfset newWidth = round(uploadedImage.width * percentage)>
<cfset newHeight = round(uploadedImage.height * percentage)>
<!--- Show Image --->
<cfoutput>
<img src="../images/about/#file.serverFile#" style="height:#newHeight#; width:#newWidth#;">
I assume I may have to do URL Passing or do some sort of CFScript. On the Return buttons Onclick event.

Answer 1

Here is my approach take it for what you will.
Ok this is probably more than you need but this should get you somewhere on this image delete problem thing.
Here is your code. But I broke it into two pages. Of course I cannot see what else is going on this page and your form handling stuff so we will start with what you are giving us.
<cfset mediapath = expandpath('../images/about')>
nice use of structKeyExists() :)
<cfif structKeyExists(form,"image") and len(form.image)>
Here I would pause and suggest you limit
your uploads to just .gif, .jpeg, .jpg, .png
(your main image types) to prevent uploading any
and everyfile type. I added an accept parameter below.
<cffile action="upload"
filefield="image"
destination="#MediaPath#"
nameconflict="makeunique"
accept="image/*">
<cfimage name="uploadedImage"
source="#MediaPath#/#file.serverFile#" >
Ok the file is uploaded lets seperate concerns
At this point I would ask them if they want to preview the file. If they click 'preview' take them to a preview.cfm page.
Then you have a file name you need to pass if you have nothing else (like an ID or some primary key).
So I pulled this handy-dandy script out of the Adobe Coldfusion docs on their website and I am going to use this to turn your filename into 'something else' ;)
<cfscript>
theKey="123abc";
theKey=generateSecretKey("AES")
superDuperSecretSoDontTell=encrypt(file.serverFile, theKey, "AES", "hex");
</cfscript>
Let's send this piggy!
and off you go to the preview page...
<cfoutput>
(pointing up) This is pageA.cfm
(pointing down) This is pageB.cfm
Now I have the rest of your code below and lets pull your file based on the pass through querystring variable/value pairs.
<cfscript>
IWannaKnowTheSecret=decrypt(url.fileName, url.theKey, "AES", "hex");
</cfscript>
Here I would pause and suggest you limit
your uploads to just .gif, .jpeg, .jpg, .png
(your main image types) to prevent uploading any
and everyfile type. I added an accept parameter below.
<cffile action="read" file="#MediaPath##IWannaKnowTheSecret#" variable="uploadedImage">
<cfset imagesize = 320>
Interesting handle here. So you are taking the
larger of the two values and using that
to percentage down the size. Neat.
<cfif uploadedImage.width GT uploadedImage.height>
<cfset percentage = (imagesize / uploadedImage.width)>
<cfelse>
<cfset percentage = (imagesize / uploadedImage.height)>
</cfif>
<cfset newWidth = round(uploadedImage.width * percentage)>
<cfset newHeight = round(uploadedImage.height * percentage)>
Then do a form like this:
<form action="" method="post" enctype="multipart/form-data">
Your current Image:
<cfoutput>
Name: #uploadedImage#<br>
<img src="../images/about/#uploadedImage#" style="height:#newHeight#; width:#newWidth#;">
</cfoutput>
Do you want to remove this?<br>
<input type="checkbox"
name="removeImage"
value="1" />: Remove the logo image</cfif><br />
Wnat to replace your image?<br>
<input type="file" name="replacementImage"> (
<input type="hidden"
name="uploadedImage"
value="<cfoutput>#uploadedImage#</cfoutput>">
<input type="submit" value="submit" name="submit"
</form>
Cancel and go back
If they continue and want to fix the image or replace it. Submit then you can use something like this.
Then we delete...
And if the replacementImage file filed is populated then we add that file.
And there you have it...
You are seperating some concerns.
You are giving improved options.
You are allowing a change or no change.
You are giving them an out to go back to where ever you want.
Edit: Here is proof for the encoding and decoding stuff (if you wanted to play with it:
<cfscript>
theKey="123abc";
theKey=generateSecretKey("AES");
superDuperSecretSoDontTell=encrypt("monkeytoots", theKey, "AES", "hex");
</cfscript>
<cfoutput>Let's send this piggy!</cfoutput>
<cfif isdefined("url.fileName") and isdefined("url.theKey")>
<cfscript>
IWannaKnowTheSecret=decrypt(url.fileName, url.theKey, "AES", "hex");
</cfscript>
<cfoutput>
#IWannaKnowTheSecret#
</cfoutput>
</cfif>

Answer 2

This answer is in response to Adam Cameron's comment. It illustrates some potentially unexpected results that can occur with two submit buttons. Start with this code.
<cfdump var="#form#">
<form action="abc.cfm" method="post">
<input type="text" name="text1" />
<input type="submit" name="submit1" value="no" />
<input type="submit" name="submit2" value="yes" />
</form>
The default behaviour of most, if not all browsers is that there are occasions whereby a form will be submitted when the user presses the enter key. What would you expect to see with this form if you had your curser in the text box and pressed Enter? Try it and see if you were right.