MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual, Page: 822 / 860

822 Chapter 37: Managing Files on the Server
Reviewing the code
The following table describes the code and its function:
Note: This example performs no error checking and does not incorporate any security measures.
Before deploying an application that performs file uploads, be sure to incorporate both error handling
and security. For more information, see
Chapter 16, “Securing Applications,” on page 345 and
Chapter 14, “Handling Errors,” on page 285 .
Resolving conflicting filenames
When you save a file to the server, there is a risk that a file with the same name might already
exist. To resolve this problem, assign one of these values to the
nameConflict
attribute of the
cffile
tag:
•
Error
(default) ColdFusion stops processing the page and returns an error. The file is not
saved.
•
Skip Allows custom behavior based on file properties. Neither saves the file nor returns an
error.
•
Overwrite Overwrites a file that has the same name as the uploaded file.
•
MakeUnique
Generates a unique filename for the uploaded file. The name is stored in the
file object variables serverFile and serverFileName. You can use this variable to record the name
used when the file was saved. The unique name might not resemble the attempted name. For
more information on file upload status variables, see
“Evaluating the results of a file upload”
on page 824 .
Controlling the type of file uploaded
For some applications, you might want to restrict the type of file that is uploaded. For example,
you might not want to accept graphic files in a document library.
You use the
accept
attribute to restrict the type of file that you allow in an upload. When an
accept
qualifier is present, the uploaded file’s MIME content type must match the criteria
specified or an error occurs. The
accept
attribute takes a comma-separated list of MIME data
names, optionally with wildcards.
A file’s MIME type is determined by the browser. Common types, such as image/gif and text/
plain, are registered in the browser.
Code Description
<cffile action="upload" Output the name and location of the uploaded file on
the client machine.
destination="c:\temp\"
Specify the destination of the file.
nameConflict="overwrite"
If the file already exists, overwrite it.
fileField="Form.FiletoUpload">
Specify the name of the file to upload. Do not
enclose the variable in pound signs.
You uploaded
#cffile.ClientFileName#.#cffile.
ClientFileExt# successfully to
#cffile.ServerDirectory#.
Inform the user of the file that was uploaded and its
destination. For information on
cffile scope
variables, see “Evaluating the results of a file upload”
on page 824 .