Serving .docx files in IE with javascript

rad131304

I've inherited this horridly designed ASP web application. Recently I got a request to fix a problem with the way that .docx files were downloading from the site. When you download .docx files in IE, it downloads them as a .zip file. It's obviously a mime-type issue, but the hosting provider doesn't allow you to define custom mime types, and apparently .docx is too fancy and new to bother defining a mime-type for.

Currently the application is using javascript's window.open command to ge the file:

window.open(fname,"newdoc");

Fine, I thought, I'll just change it to:

var doc = window.open("","newdoc");
if(fname.match(/\.docx$/).length > 0) {doc.ContentType = "vnd.openxmlformats-officedocument.wordprocessingml.document";}
doc.location.replace(fname);

but this didn't really get me anywhere. I'm guessing that I lost the ContentType assignment when I do the replacement, but I don't really have any other ideas at this point besides 1) opening the file server side and streaming it, or 2) completely rewriting. Neither appeals all that much.

I know that this, oddly, is a "security feature" of IE, where it ignores the extension when you aren't in the intranet zone (my localhost version doesn't have the .docx to .zip extension problem). The truth is, it's simple enough to solve without actually fixing, (save as, change the extension or just don't use IE) ... but I need to fix it. Any ideas?

Not that it will solve your problem, but you forgot the first part of the media type: it's "application/vnd.openxmlformats-officedocument.wordprocessingml.document".

rad131304

@Spectre said:

Not that it will solve your problem, but you forgot the first part of the media type: it's "application/vnd.openxmlformats-officedocument.wordprocessingml.document".

True - unfortunately (or fortunately) it was actually correct in the code.

rad131304

var doc = window.open(fname,"newdoc");
if(fname.match(/\.docx$/).length > 0) {doc.ContentType = "application/vnd.openxmlformats-officedocument.wordprocessingml.document";}

<FONT face=Arial>apparently works, albiet quite strangely (the download launches with the proper extension, but a zip icon, then prompts you to save the .docx file properly). So solved?</FONT>

<FONT face=Arial>Edit: not solved, this only works on XP apparently ....</FONT>

blakeyrat

I think the only real solution here is to either talk your hosting provider into fixing their servers, or move hosting.

Can you add ad-hoc MIME types to web.config? Maybe try this?

rad131304

@blakeyrat said:

I think the only real solution here is to either talk your hosting provider into fixing their servers, or move hosting.
Can you add ad-hoc MIME types to web.config? Maybe try this?

No dice, Network Solutions is useless. I'm just going to migrate the download function to server-side so I can send the correct mime-type. I should have just done that from the beginning.

blakeyrat

@rad131304 said:

@blakeyrat said:
I think the only real solution here is to either talk your hosting provider into fixing their servers, or move hosting.

Can you add ad-hoc MIME types to web.config? Maybe try this?

No dice, Network Solutions is useless. I'm just going to migrate the download function to server-side so I can send the correct mime-type. I should have just done that from the beginning.

I've had really good support from Network Solutions, at least as far as security certificates go. Looks like their hosting is useless, though... shame.

rad131304

@blakeyrat said:

I've had really good support from Network Solutions, at least as far as security certificates go. Looks like their hosting is useless, though... shame.

Yes, that's pretty much the state of it (their managed hosting at least).

intertravel

@rad131304 said:

I've inherited this horridly designed ASP web application. Recently I got a request to fix a problem with the way that .docx files were downloading from the site. When you download .docx files in IE, it downloads them as a .zip file. It's obviously a mime-type issue, but the hosting provider doesn't allow you to define custom mime types, and apparently .docx is too fancy and new to bother defining a mime-type for.

Currently the application is using javascript's window.open command to ge the file:
window.open(fname,"newdoc");
Fine, I thought, I'll just change it to:
var doc = window.open("","newdoc");
if(fname.match(/\.docx$/).length > 0) {doc.ContentType = "vnd.openxmlformats-officedocument.wordprocessingml.document";}
doc.location.replace(fname);
but this didn't really get me anywhere. I'm guessing that I lost the ContentType assignment when I do the replacement, but I don't really have any other ideas at this point besides 1) opening the file server side and streaming it, or 2) completely rewriting. Neither appeals all that much.

I know that this, oddly, is a "security feature" of IE, where it ignores the extension when you aren't in the intranet zone (my localhost version doesn't have the .docx to .zip extension problem). The truth is, it's simple enough to solve without actually fixing, (save as, change the extension or just don't use IE) ... but I need to fix it. Any ideas?

I think it's a client-side issue, not a server-side problem. Whoever does desktop support for the users needs to change their IE settings - somewhere in the custom security settings is an option for "Open file based on content, not file extension" which is enabled by default. Add the site in question to 'trusted sites' and disable the relevant setting for only those sites. You could also try setting the mime-type to the one for old Word docs - might work to fool IE, but I'm not sure.

rad131304

FWIW, here is the solution that I came up with:

    'set up connection
    Dim conString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Server.MapPath("XXXX.MDB")
    Dim conProvider As String = System.Configuration.ConfigurationManager.ConnectionStrings("FOO").ProviderName()
Dim mime_type, filename, path As String
Dim filequery, mimequery As SqlDataSource
Dim fileresult, mimeresult As IEnumerator
Dim info As System.IO.FileInfo

'get file name
filequery = New SqlDataSource
With filequery
    .ProviderName = conProvider
    .ConnectionString = conString
    .SelectCommand = "select [file_name] from [doc] where [id] = @id"
    .SelectParameters("@id") = New Parameter("@id", Data.DbType.Int32, Request.QueryString("id").ToString())
End With
queryresult = filequery.Select(DataSourceSelectArguments.Empty).GetEnumerator()
queryresult.MoveNext()
filename = queryresult.Current.Item(0).ToString()

queryresult = Nothing
filequery = Nothing

'get info about file
path = Server.MapPath(".\Business\" &amp; filename)
info = New System.IO.FileInfo(path)

'get file's mime-type
mimequery = New SqlDataSource
With mimequery
    .ProviderName = conProvider
    .ConnectionString = conString
    .SelectCommand = "select [mime_type] from [mime_type] where [ext] = @ext"
    .SelectParameters("@ext") = New Parameter("@ext", Data.DbType.String, info.Extension)
End With
mimeresult = mimequery.Select(DataSourceSelectArguments.Empty).GetEnumerator()
mimeresult.MoveNext()
mime_type = mimeresult.Current.Item(0).ToString()

mimeresult = Nothing
mimequery = Nothing

'send file to user
With Response
    .AppendHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0")
    .AppendHeader("Content-Description", "File Transfer")
    .AppendHeader("Content-type", mime_type)
    .AppendHeader("Content-Length", info.Length)
    .AppendHeader("Content-Disposition", "attachment; filename=" &amp; filename)
    .WriteFile(path)
End With

<FONT face=Arial></FONT>

toth

@rad131304 said:

.SelectCommand = "select [mime_type] from [mime_type] where [ext] = @ext"

Is it really necessary to use a database to store MIME type associations? Wouldn't hard-coding, or at least flat-filing, the associations avoid DB query costs?

rad131304

@toth said:

@rad131304 said:
.SelectCommand = "select [mime_type] from [mime_type] where [ext] = @ext"
Is it really necessary to use a database to store MIME type associations? Wouldn't hard-coding, or at least flat-filing, the associations avoid DB query costs?

IDK if I said this before, but it's not just serving docx files, those were just the ones IE was failing on. Flat filing would have worked, too. I wasn't concerned about the DB costs as it's only used by a dozen people a couple of times a year.

Medezark

I'm doing something like this, which seems to work.

Select Case ext

Case ".htm", ".html"

type = "text/HTML"

Case ".txt"

type = "text/plain"

Case ".doc", ".rtf"

type = "Application/msword"

Case ".csv", ".xls"

type = "Application/x-msexcel"

Case ".manifest"

type = "application/manifest"

Case ".xaml"

type = "application/xaml+xml"

Case ".application"

type = "application/x-ms-application"

Case ".deploy"

type = "application/octet-stream"

Case ".xbap"

type = "application/x-ms-xbap"

Case ".docm"

type = "application/vnd.ms-word.document.macroEnabled.12"

Case ".docx"

type = "application/vnd.openxmlformats-officedocument.wordprocessingml.document"

Case ".dotm"

type = "application/vnd.ms-word.template.macroEnabled.12"

Case ".dotx"

type = "application/vnd.openxmlformats-officedocument.wordprocessingml.template"

Case ".potm"

type = "application/vnd.ms-powerpoint.template.macroEnabled.12"

Case ".potx"

type = "application/vnd.openxmlformats-officedocument.presentationml.template"

Case ".ppam"

type = "application/vnd.ms-powerpoint.addin.macroEnabled.12"

Case ".ppsm"

type = "application/vnd.ms-powerpoint.slideshow.macroEnabled.12"

Case ".ppsx"

type = "application/vnd.openxmlformats-officedocument.presentationml.slideshow"

Case ".pptm"

type = "application/vnd.ms-powerpoint.presentation.macroEnabled.12"

Case ".pptx"

type = "application/vnd.openxmlformats-officedocument.presentationml.presentation"

Case ".xlam"

type = "application/vnd.ms-excel.addin.macroEnabled.12"

Case ".xlsb"

type = "application/vnd.ms-excel.sheet.binary.macroEnabled.12"

Case ".xlsm"

type = "application/vnd.ms-excel.sheet.macroEnabled.12"

Case ".xlsx"

type = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"

Case ".xltm"

type = "application/vnd.ms-excel.template.macroEnabled.12"

Case ".xltx"

type = "application/vnd.openxmlformats-officedocument.spreadsheetml.template"

Case Else

type = "text/plain"

End Select

Dim buf As Byte() = TBL.Rows(0)!DOCUMENT

If type <> "" Then

Response.ContentType = type

End If

Response.BinaryWrite(buf)

Response.End()

rad131304

@Medezark said:

I'm doing something like this, which seems to work.



Select Case ext

I wanted to separate the application logic from the available mime-types, which is why I chose not to do it with a select case statement.

Medezark

@rad131304 said:

@Medezark said:
I'm doing something like this, which seems to work.



Select Case ext

I wanted to separate the application logic from the available mime-types, which is why I chose not to do it with a select case statement.

Just another way of doing the same thing -- without a round trip to the db. Your way has advantages.