After searching a number of blog posts, stumbling this, and reading Adobe's documentation, it appears that the consensus is "multiple" file upload support is not supported with CF10 (unless you're doing the flash forms). The issue being, "uploadall" value for the cffile tag may upload all of the files, but you aren't returned an array of results regarding the files.
Here's a function I threw together that utilized the underlying Java methods and tested in ACF 10.
<cffunction name="getUploadedFiles" access="public" returntype="struct"
hint="Gets the uploaded files, grouped by the field name">
<cfset var local = {
files = {},
types = "text/plain,text/csv,application/msexcel,application/vnd.ms-excel,application/octet-stream",
tempFiles = form.getTempFiles(),
idx = 0} />
<cfscript>
arrayEach(form.getPartsArray(), function (field) {
var local = {fieldName = field.getName(), destinationFile = ""};
// Make sure the field available in the form is also
// available for the temporary files
if (structKeyExists(tempFiles, fieldName)) {
// Create the files of field array if it doesn't exist
if (!structKeyExists(files, fieldName)) {
files[fieldName] = [];
}
// If only 1 file was uploaded, it won't be an array - so make it one
if (!isArray(tempFiles[fieldName])) {
tempFiles[fieldName] = [tempFiles[fieldName]];
}
// Check that the form part is a file and within our list of valid types
if (field.isFile() && listFindNoCase(types, field.getContentType())) {
// Compile details about the upload
arrayAppend(files[fieldName], {
file = tempFiles[fieldName][++idx],
filePart = field,
filename = field.getFileName(),
filepath = field.getFilePath(),
contentType = field.getContentType(),
tempFile = tempFiles[fieldName][idx].getPath()
});
}
}
});
</cfscript>
<cfreturn local.files />
</cffunction>
Following along with the comments, this just loops over all the form parts, finding the files, and creating an array containing some useful file details (and filtering by specific content types per my application requirements).
Then, I created the uploadFile function which takes in fieldName and destinationPath arguments. I get the array of uploaded files based on the field I pass in, loop through the files to ensure the destination filepath does not exists (and make it unique if so), and then write the destination file using the contents of the java.io.File object that is referenced from the temporary upload.
<cffunction name="uploadFile" access="public" returntype="array"
hint="Uploads a file (or multiple files) from the form to the server">
<cfargument name="fieldName" type="string" required="true" />
<cfargument name="destinationPath" type="string" required="true" />
<cfset var local = {files = [], filepaths = [], allFiles = getUploadedFiles()} />
<cfif structKeyExists(local.allFiles, arguments.fieldName)>
<cfset local.files = local.allFiles[arguments.fieldName] />
</cfif>
<cfloop array="#local.files#" index="local.file">
<cfset local.file.destinationFile = arguments.destinationPath & local.file.fileName />
<cfif fileExists(local.file.destinationFile)>
<cfset local.file.destinationFile = listFirst(local.file.destinationFile, ".") & "_#getTickCount()#.csv" />
</cfif>
<cfset fileWrite(local.file.destinationFile, fileRead(local.file.file)) />
<cfset arrayAppend(local.filePaths, local.file.destinationFile) />
</cfloop>
<cfset setActiveFileName(local.filePaths[arrayLen(local.filePaths)]) />
<cfreturn local.filePaths />
</cffunction>
Now I have full control over all the files being uploaded, and can handle the results has needed.