Getting The MetaData For A File Upload In ColdFusion

<cffunction
	name="getFileUploadMetaData"
	access="public"
	returntype="struct"
	output="false"
	hint="I return the meta data of the file upload contained in the given form field.">

	<!--- Define arguments. --->
	<cfargument
		name="fileField"
		type="string"
		required="true"
		hint="I am the form field that contains the given file."
		/>

	<!--- Define the local scope (testing on CF8). --->
	<cfset var local = {} />

	<!---
		Get the system's temp directory. We'll be "uploading" the
		file here in order to query for its properties.
	--->
	<cfset local.tempDirectory = getTempDirectory() />

	<!--- Upload the file to the temp directory. --->
	<cffile
		result="local.upload"
		action="upload"
		filefield="#arguments.fileField#"
		destination="#local.tempDirectory#"
		nameconflict="makeunique"
		/>

	<!---
		Since we don't need the physical file anymore, let's delete
		it immediately.
	--->
	<cfset fileDelete( "#local.tempDirectory##local.upload.serverFile#" ) />

	<!---
		Create the meta data for the file. Since the temp directory
		doesn't afford proper naming, and we don't know how the user
		is going to save the file, we can really only capture the
		client-name in a meaningful way.
	--->
	<cfset local.metaData = {
		clientFile = local.upload.clientFile,
		clientFileExt = local.upload.clientFileExt,
		clientFileName = local.upload.clientFileName,
		contentSubType = local.upload.contentSubType,
		contentType = local.upload.contentType,
		fileSize = local.upload.fileSize
		} />

	<!--- Return the meta data. --->
	<cfreturn local.metaData />

</cffunction>



<!--- ----------------------------------------------------- --->
<!--- ----------------------------------------------------- --->
<!--- ----------------------------------------------------- --->
<!--- ----------------------------------------------------- --->



<!--- Param the form fields for the submit. --->
<cfparam name="form.submitted" type="boolean" default="false" />
<cfparam name="form.file" type="string" default="" />

<!--- I will hold errors generated during the upload processing. --->
<cfset errorMessage = "" />

<!--- I will hold the name of the uploaded file (if successful). --->
<cfset imagePath = "" />


<!--- Set the path for the uploads folder. --->
<cfset uploadDirectory = expandPath( "./uploads/" ) />


<!--- ----------------------------------------------------- --->
<!--- ----------------------------------------------------- --->


<!--- Check to see if the form has been submitted. --->
<cfif form.submitted>


	<cftry>

		<!--- Make sure a file was selected. --->
		<cfif !len( form.file )>

			<cfthrow
				type="FileNotFound"
				message="Please select a file to upload."
				/>

		</cfif>


		<!--- Get the meta data for the uploaded file. --->
		<cfset metaData = getFileUploadMetaData( "file" ) />

		<!---
			Check to see if we should continue processing. If the
			file is not an image, there's nothing more to do. In this
			case, we are checking the reported file type and content
			type of the post.
		--->
		<cfif (
			!reFind( "(?i)jpe?g|png|gif", metaData.clientFileExt ) ||
			(metaData.contentType neq "image")
			)>

			<!--- ALERT: Possible Attack!! --->
			<cfthrow
				type="InvalidImageFile"
				message="Please select a valid image file."
				/>

		</cfif>


		<!---
			If we've made it this far, then we know the user has
			selected a valid image file. Now, we want to move the
			file into the uploads directory. Let's use the CFFile
			tag AGAIN in order to let ColdFusion handle the file
			conflict resolution.
		--->
		<cffile
			result="upload"
			action="upload"
			filefield="file"
			destination="#uploadDirectory#"
			nameconflict="makeunique"
			/>

		<!---
			Set the path of the image so we can display it back
			to the user.
		--->
		<cfset imagePath = "./uploads/#upload.serverFile#" />


		<!--- Catch any upload processing errors. --->
		<cfcatch>

			<!--- Set the error message for the user. --->
			<cfset errorMessage = cfcatch.message />

		</cfcatch>

	</cftry>


</cfif>


<!--- ----------------------------------------------------- --->
<!--- ----------------------------------------------------- --->


<!--- Reset the output buffer. --->
<cfcontent type="text/html; charset=utf-8" />

<cfoutput>

	<!doctype html>
	<html>
	<head>
		<title></title>
	</head>
	<body>

		<h1>
			Upload An Image
		</h1>


		<!--- Check to see if we have an error message to display. --->
		<cfif len( errorMessage )>

			<p>
				<strong>Ooops:</strong> <em>#errorMessage#</em>
			</p>

		</cfif>


		<form
			method="post"
			action="#cgi.script_name#"
			enctype="multipart/form-data">

			<input type="hidden" name="submitted" value="true" />

			<p>
				Please select an Image to upload:<br />
			</p>

			<p>
				<input type="file" name="file" size="30" />
				<input type="submit" value="Upload Image" />
			</p>

		</form>


		<!---
			Check to see if we have an uploaded image to display
			back to the user.
		--->
		<cfif len( imagePath )>

			<h3>
				Your Upload:
			</h3>

			<p>
				<img src="#imagePath#" width="400" />
			</p>

		</cfif>

	</body>
	</html>

</cfoutput>