Making Microsoft Office to Work with WebDAV Server

Microsoft Office can open files from WebDAV server and save them back to server without the need to download them to local file system. To achieve this the following conditions must be met:

  1. Your WebDAV server must support Class 2. Microsoft Office locks documents when creating and opening files for editing. If Microsoft Office is unable to lock the document it will be opened as read-only.

  2. Your WebDAV server must be configured on site root in case of MS Office 2007 or earlier. Microsoft Office 2007 and earlier may submit OPTIONS and PROPFIND requests to site root (http://server/) and requires the server to respond properly. If your WebDAV server is non-root (for example http://server/dav/) Microsoft Office may open documents as read-only. There is no this issue with MS Office 2010 and later versions.

Note that this will only enable Microsoft Office to open files from WebDAV server using Windows Shell (Web Folders / miniredirector), via Microsoft Office 'Open' menu or starting a Microsoft Office application passing a document URL as a parameter. Hyperlinked documents will still open as read-only.

Opening Web-hyperlinked Microsoft Office documents in read-write mode

If you click on a hyperlink on a web page in a browser Microsoft Office will open a document as read-only. This is a default Microsoft Office behavior. To open a document in read-write mode you can use one of the following approaches:

  • Use FFWinPlugin in case of Chrome, FireFox and Safari, or SharePoint.OpenDocuments ActiveX in case of Internet Explorer or Microsoft Office 2013 protocols.
    FFWinPluginSharePoint.OpenDocuments ActiveX and protocol handlers are installed with Microsoft Office by default.

  • Use IT Hit WebDAV Ajax Library, it detects MS Office version installed, a web browser and OS and chooses the best available method for opening this type of document depending on file type. See Opening Microsoft Office Documents and Other Types of Files for Editing From a Web Page.

  • Set OpenDocumentsReadWriteWhileBrowsing DWORD Value on a client machine under the key
    HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Common\Internet.
    Set the Value data to 1.

Microsoft Office Authentication

To open the document from server, Microsoft Office is using two different components one of which is the Microsoft miniredirector. Some versions of the miniredirector on Windows XP and 2003 require OPTIONS request to be processed without authentication when Basic or Digest is used. So in this case you will need to enable unauthenticated OPTIONS requests.

On the contrary, all PROPFIND requests must be authenticated, unless the server is anonymous. If any of the PROPFIND requests are processed without authentication, while others request authentication, Microsoft Office may open your file as read-only.

Important! Microsoft Office 2010 and later versions as well as Windows Shell (Web Folders / miniredirector) requires secure SSL connection when used with Basic authentication. Microsoft Office 2010 will fail to open a document via insecure connection with Basic authentication. For a workaround please see this article: You cannot open Office file types directly from a server that only supports Basic Authentication over a non SSL connection with Office 2010 applications.

Microsoft Office applications always ask for the authentication when used with Basic and Digest authentication. If you check "Remember my password" checkbox it will still display the login dialog, but the user name and password will be already filled-in, so you just click "OK". If NTLM or Kerberos is used than MS Office asks for credentials only 1 time during first document access.

 

How do I avoid login dialog when using Microsoft Office?

Here are some options to consider to totally avoid login dialog with Microsoft Office:

 

Why Microsoft Office still opens my document as read-only?

Here are some troubleshooting tips if Microsoft Office files open as read-only from a WebDAV server.

  1. Examine the server log for exceptions. Before opening the document from WebDAV server, Microsoft Office submits LOCK request. This request must succeed, otherwise the document will be opened as read-only. Depending on Microsoft Office version, operating system it may submit a bunch of other requests. Check your server log and make sure all requests were successful.

  2. Examine WebDAV requests with a Fiddler tool. While all requests that reached the WebDAV server Engine are logged, if the request failed before hitting the Engine you will not see it in a log. Usually this happens if the request failed during authentication stage. In this case use the free Fiddler tool or any other debugging proxy to examine the requests.

    Note that to capture requests using Fiddler on 'localhost' you must use 'localhost.fiddler' instead of 'localhost' when connecting to server, for example: http://localhost.fiddler:1234.

  3. Clear Microsoft Office WebDAV cache in registry. Microsoft Office reads WebDAV server options when connecting to server first time and stores them for later use. If your server settings has changed during development (or you just fixed some server issues) you may need to delete this settings. The Microsoft Office WebDAV cache is stored under the key:

    HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Common\Internet\Server Cache\

    To clear cache just delete all keys under this key. In a development environment we suggest always clearing the cache if your WebDAV server class has changed or after authentication scheme has changed. As an alternative to deleting cache, you can just reconfigure your server to run on a different port.

    Note that in production environment usually you do not need to clear this cache or change port as soon as you server settings do not change often while Microsoft Office will re-request server options after some time.

  4. Exclude client side MS Office issues. Finally there could be issues with Microsoft Office installation or components registration. Use our demo WebDAV server (or any Class 2 WebDAV server sample provided with SDK) to open, edit and save MS Office documents. Open www.ajaxfilebrowser.com on a computer with MS Office installed, than right-click on Microsoft Office document in files list pane and select Edit command in context menu. Select OK in the File Download warning popup window. The document should open in read-write mode and you can click Save button on a toolbar to save document directly to server.