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<TITLE>AspUpload.com - User Manual. Chapter 3</TITLE>
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<A HREF="manual_db.html"><IMG BORDER="0" SRC="next.gif" ALIGN="RIGHT" ALT="Chapter 4: Saving Files and/or Filenames in the Database"></A>
<A HREF="manual_simple.html"><IMG BORDER="0" SRC="previous.gif" ALIGN="RIGHT" ALT="Chapter 2: Uploading Files and Text Items"></A>
<B><U><FONT SIZE="3" COLOR="#990000">Chapter 3. Uploading to Memory</FONT></U></B>
<P>
<B><FONT COLOR="#0000A0">Calling Upload.Save with no Arguments</FONT></B>
<BLOCKQUOTE>
The <I>Path</I> parameter to the method <B>Upload.Save</B>
is optional: the method can be called with no arguments at all, as follows:
<P>
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<B>
Set Upload = Server.CreateObject("Persits.Upload")<BR>
Upload.Save
</B>
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<P>
If a folder path is not passed in, the Save method does not save
uploaded files to disk. Instead it creates memory images of the files
that can be accessed via the Upload.Files collection. A memory file
can then be saved to disk via the <B>File.SaveAs</B>
method. You may also use the property <B>File.Binary</B>
to save the file in the database, as shown in the next chapter.
<P>
Note that AspUpload 2.x used the method <B>Upload.SaveToMemory</B>
to perform memory uploads. This method is still supported for backwards
compatibility, but it is equivalent to Upload.Save with the <I>Path</I> argument omitted.
</BLOCKQUOTE>
<B><FONT COLOR="#0000A0">Why Upload to Memory</FONT></B>
<BLOCKQUOTE>
Memory uploads provide several major advantages over regular uploads:
<UL>
<LI><B>Access to form items</B>. You cannot access
text fields on your form until after the Save method is called. Therefore, if you need to access a form item
before saving a file to disk, uploading to memory is the only way to do it.
<LI><B>Access to file names</B>. You can check
whether a file with the same name already exists in a directory
before saving the uploaded file to disk.
<LI><B>Simplified renaming and copying</B>. A regular upload saves all the files
in the same directory, and under their original names. Uploading to memory
makes the task or renaming and copying files easier to code.
<LI><B>Performance and security</B>. If the ultimate destination
of an uploaded file is a database table, you can use memory uploads
to save your file in the database directly from memory without saving it to disk first.
</UL>
<P>
The main disadvantage of memory uploads is that it cannot be used with
large files as it is very memory-intensive. You should always use
SetMaxSize with memory uploads to limit the size of the memory imprints of files.
</BLOCKQUOTE>
<B><FONT COLOR="#0000A0">Accessing Form Items</FONT></B>
<BLOCKQUOTE>
The following code sample enables a user to select a destination
subdirectory underneath the c:\upload folder to upload a file to.
The sample form (file <B>formitems.asp</B>) contains a file item
and a drop-down list box:
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<h3>Using memory uploads to access form items</h3><P>
<FORM METHOD="POST" ENCTYPE="multipart/form-data" ACTION="formitems_upload.asp"><BR>
Select file: <INPUT TYPE="FILE" SIZE="40" NAME="FILE1"><BR><BR>
Select destination subdirectory:<P>
<SELECT NAME="Subdir"><BR>
<OPTION>Folder1</OPTION><BR>
<OPTION>Folder2</OPTION><BR>
<OPTION>Folder3</OPTION><BR>
</SELECT><BR>
<BR><BR>
<INPUT TYPE=SUBMIT VALUE="Upload!"><BR>
</FORM><BR>
</BODY><BR>
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<P>
The corresponding upload script <B>formitems_upload.asp</B>
uploads the file to memory, then creates a user-specified subfolder
and saves the file in it:
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<%<BR>
Set Upload = Server.CreateObject("Persits.Upload")<P>
</B>' we use memory uploads, so we must limit file size<B><BR>
Upload.SetMaxSize 100000, True<P>
</B>' Save to memory. Path parameter is omitted<B><BR>
Upload.Save<P>
</B>' Access subdirectory specified by user<B><BR>
subdir = Upload.Form("subdir")<P>
</B>' Build path string<B><BR>
Path = "c:\upload\" & subdir<P>
</B>' Create path, ignore "already exists" error<B><BR>
Upload.CreateDirectory Path, True<P>
</B>' Save files to it. Our form has only one file item<BR>
' but this code is generic.<B><BR>
For Each File in Upload.Files<BR>
File.SaveAs Path & "\" & File.FileName<BR>
Response.Write "File saved as " & File.Path & "<BR>"<BR>
Next<BR>
%><BR>
</BODY><BR>
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<P>
Click the link below to run this code sample:
<P>
<B><A TARGET="_new" HREF="http://localhost/aspupload/03_memory/formitems.asp">http://localhost/aspupload/03_memory/formitems.asp</A></B>
<A HREF="javascript:;" OnClick="open('helppopup.html','','width=400,height=400');"><IMG SRC="help.gif" BORDER="0" ALT="Why is this link not working?"></A>
</BLOCKQUOTE>
<B><FONT COLOR="#0000A0">Accessing File Names</FONT></B>
<BLOCKQUOTE>
The next code sample uploads a file to memory, the checks whether
a file with the same name already exists in the destination directory,
and if so, alerts a user. Otherwise the file is saved to disk.
The form file <B>filename.asp</B> contains a single file item and is not shown here.
The corresponding upload script <B>filename_upload.asp</B> uses the method
<B>FileExists</B> to determine whether the file already exists:
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