Opening Excel Documents from the WCI Knowledge Directory

Matt Chiste — Sun, 14 Feb 2010 15:19:41 +0000

I had a client report this strange issue with Excel file handling in IE7 and IE8 (and Office 2007). Basically, every time someone would open a document, it would get cached by IE. But the next time the person would try to open the same document, they’d get a “file is locked by user” message. It seemed IE was caching the file in the Temporary Files folder, then when the user would click the link a second time there was a conflict between the existing file in that folder and the new one IE was trying to bring in. I found some articles and discussions on the topic, but most came back to making changes on the client-side, which is never easy to do in an enterprise. Even if it’s a little trickier to execute, you should always try to make changes on the WebCenter Portal side.

In this case, after downloading the Excel file the first time, I confirmed it was in my Temporary Internet Files folder:

I was also able to verify that the portal was returning a “Not-Modified” header when the user tried to open this Excel document again:

The fix I applied here? Another BigIP iRule that turns off caching of Excel files – after the jump.

The BigIP iRule is:

if { [HTTP::header Content-Type] contains "ms-excel"} {
    HTTP::header replace "Expires" "-1"
    HTTP::header remove "ETag"
 }

… and as you can see, the HTTP headers now make sure the content isn’t cached, which prevents Excel from failing when opening cached documents:

This fix doesn’t feel like the best approach, but it has worked for me. Have you had this problem yourself? Got a better resolution/workaround? Let us know in the comments!

Fix KD Handling of HTML Docs

Matt Chiste — Fri, 22 Jan 2010 04:45:54 +0000

In ALUI 6.5, and following through to 10gR3 and the latest patches, Oracle changed the way documents are opened in the Knowledge Directory. This change was to get a little better browser compatibility so that when a user clicks on a document in the KD, the user is always presented with the usual Open/Save Dialog box.

Many WCI clients have HTML files in their Knowledge Directories, whether they’re crawled in from Publisher, Collaboration Server, or uploaded from some other source. In version 6.1 and before, the behavior of the portal was simply to open these files directly in the browser, but that changed with 6.5. Unfortunately, Oracle has asserted that this is “expected behavior” and while an enhancement request has been submitted, there are no promises about the behavior changing in 11g. The good news is that there’s a relatively simple fix for this behavior. Unfortunately, the “relatively simple” fix assumes you’ve got BigIP load balancing requests to your portal, but if not, hopefully this post will give you some ideas on how to resolve the problem in your environment.

The problem is caused by the portal returning an HTTP header called “Content-Disposition”:

: Content Disposition Header

The trick is to remove this header for HTML documents. I’ve tried writing ISAPI filters unsuccessfully, but for the clients that needed the fix, they had BigIP.

Hit the link to see the BigIP iRule to resolve this issue.

if { [HTTP::header Content-Disposition] contains "attachment"}
{
    if { [HTTP::header Content-Type] contains "text/html" }
    {
        HTTP::header remove "Content-Disposition"
    }
}

This iRule simply says “if there’s a Content-Disposition Header, and the Content Type is HTML, remove that header”.

WebCenter Interaction, ALUI, Plumtree blog by Integryst » BigIP

Opening Excel Documents from the WCI Knowledge Directory

Fix KD Handling of HTML Docs