Classic ASP download PDF on page load - vbscript

Question

I want to create a page that can display a message "Your download is about to begin" and then after a couple seconds open a "save as" dialogue which allows the visitor to download a file. Is this possible in Classic ASP VB Script? I know how to make a page stream a file, but it doesn't show the html of the page. The file I am offering is 20Mb so the script needs to handle large files sizes.
I currently have a meta redirect in place:
<meta http-equiv="refresh" content="2; url=/downloads/brochures/ACET_Products_and_Services_Directory_2013-14.pdf" />
But this isn't really any good.
I have asppdf installed on my server, and gave this a go:
<%
Set Pdf = Server.CreateObject("Persits.Pdf")
Set Doc = Pdf.OpenDocument("d:/websites/common/downloads/brochures/ACET_Products_and_Services_Directory_2013-14.pdf")
Doc.SaveHttp "attachment;filename=ACET_Products_and_Services_Directory_2013-14.pdf"
%>
This gets around the large file, but you can't stream the file and display HTML at the same time.
I have found plenty of ways to stream the file to the browser, but I can't it to do this after the page has been displayed.
This is another one I have tried:
<%
Response.Buffer = False
Server.ScriptTimeout = 30000
Response.ContentType = "application/x-unknown" ' arbitrary
fn = "ACET_Products_and_Services_Directory_2013-14.pdf"
FPath = "d:\websites\common\downloads\brochures\" & fn
Response.AddHeader "Content-Disposition", "attachment; filename=" & fn
Set adoStream = CreateObject("ADODB.Stream")
chunk = 2048
adoStream.Open()
adoStream.Type = 1
adoStream.LoadFromFile(FPath)
iSz = adoStream.Size
Response.AddHeader "Content-Length", iSz
For i = 1 To iSz \ chunk
If Not Response.IsClientConnected Then Exit For
Response.BinaryWrite adoStream.Read(chunk)
Next
If iSz Mod chunk > 0 Then
If Response.IsClientConnected Then
Response.BinaryWrite adoStream.Read(iSz Mod chunk)
End If
End If
adoStream.Close
Set adoStream = Nothing
Response.End
%>
With this I get a Error code: ERR_INVALID_RESPONSE from Chrome.
This is one that I have tried that almost works:
<%
strFilePath = "d:/web sites/common/downloads/brochures/ACET_Products_and_Services_Directory_2013-14.pdf"
Set objFSO = Server.CreateObject("Scripting.FileSystemObject")
If objFSO.FileExists(strFilePath) Then
Set objFile = objFSO.GetFile(strFilePath)
intFileSize = objFile.Size
Set objFile = Nothing
strFileName = "ACET_Products_and_Services_Directory_2013-14.pdf"
Response.AddHeader "Content-Disposition","attachment; filename=" & strFileName
Response.ContentType = "application/x-msdownload"
Response.AddHeader "Content-Length", intFileSize
Set objStream = Server.CreateObject("ADODB.Stream")
objStream.Open
objStream.Type = 1 'adTypeBinary
objStream.LoadFromFile strFilePath
Do While Not objStream.EOS And Response.IsClientConnected
Response.BinaryWrite objStream.Read(1024)
Response.Flush()
Loop
objStream.Close
Set objStream = Nothing
Else
Response.write "Error finding file."
End if
Set objFSO = Nothing
%>
I then used <% response.redirect("download.asp") %> on the page I want it to download from, but as soon as I hit the page I get the file, but no page. Its this part I am struggling with.
SUCCESS!
<script>
window.location.replace('download.asp');
</script>
Cheers,
Steve

Answer 1

With a little more trial and error I discovered creating a file called download.asp and putting this code in worked:
<%#LANGUAGE="VBSCRIPT" CODEPAGE="65001"%>
<%
strFilePath = "d:/websites/common/downloads/brochures/ACET_Products_and_Services_Directory_2013-14.pdf"
Set objFSO = Server.CreateObject("Scripting.FileSystemObject")
If objFSO.FileExists(strFilePath) Then
Set objFile = objFSO.GetFile(strFilePath)
intFileSize = objFile.Size
Set objFile = Nothing
strFileName = "ACET_Products_and_Services_Directory_2013-14.pdf"
Response.AddHeader "Content-Disposition","attachment; filename=" & strFileName
Response.ContentType = "application/pdf"
Response.AddHeader "Content-Length", intFileSize
Set objStream = Server.CreateObject("ADODB.Stream")
objStream.Open
objStream.Type = 1 'adTypeBinary
objStream.LoadFromFile strFilePath
Do While Not objStream.EOS And Response.IsClientConnected
Response.BinaryWrite objStream.Read(1024)
Response.Flush()
Loop
objStream.Close
Set objStream = Nothing
Else
Response.write "Error finding file."
End if
Set objFSO = Nothing
%>
I then placed this code on the page I wanted to display the instructions and then offer the automatic download:
<script>
window.location.replace('download.asp');
</script>
I hope someone else finds this useful.
Steve