Integrating LibreOffice with SharePoint – part 2

In my previous post, I discuss LibreOffice‘s CMIS integration with SharePoint. This post, as promised, is dedicated to WebDAV method of accessing SharePoint servers from LibreOffice.

Basic WebDAV support is already present in LibreOffice, which inherits it from You may put SharePoint URL into OS’s File Open dialog, and browse and open documents as if they were on local file system. But to claim SharePoint WebDAV support, LibreOffice should provide ease of use no less than its competitors.

Existing users of MS Office are used to access the documents on SharePoint server using web browser integration. This allows to navigate to a document and open it in associated office program simply clicking on its link on web page, or using the page’s options to check-out document, open it for reading, etc. A document that is open this way isn’t downloaded by browser to be opened by application locally, but is open by office application via WebDAV, thus presenting easy way to work with document, including saving your work to proper place automatically. This integration is now available for all modern browsers (the level of feature support vary, though).


There are two mechanisms used to enable such integration. The first (and older) one is using ActiveX control/browser plugin. This method works for IE (classic mode) using OpenDocuments ActiveX control (and also used to work for Firefox and Chrome using NPAPI plugin, but since NPAPI was deprecated, it doesn’t work there anymore). In essence, a JavaScript click handler on the page instantiates the control, and then uses its methods to open the document with corresponding application in required mode. With all implied security considerations.

The second (newer) method is using custom URI schemes. This requires that corresponding URI handler be registered in OS/browser, and the handler application be able to recognize these URIs and extract actual WebDAV URIs required to access the document on server from them.

Both methods were lately addressed in LibreOffice development by Collabora Productivity. To implement first method, a custom ActiveX control was coded, and is now awaiting review on gerrit.

To utilize SharePoint custom URIs, LibreOffice was taught to recognize MS Office’s existing custom URIs. This is required to allow using LibreOffice to open MS Office’s documents from SharePoint on those computers that don’t have MS Office installed. But that’s not enough; we should be able to treat ODF independently, e.g. to allow for configurations where both LibreOffice and MS Office co-exist on a workstation, and must handle their respective native formats. To achieve that, we introduced our own custom URI scheme, vnd.libreoffice.command. Now LibreOffice can accept any of these URIs, and successfully open the document in proper mode.

But for LibreOffice to open them, these URIs must be passed to it from the SharePoint web page. We added registration of our own custom URI handler into installer for Windows OS, and also we now register LibreOffice as MS Office URIs handler if user chooses to register MS formats to open with LibreOffice.

If you choose to use the second (custom URI) integration method, and you don’t need MS Office as handler for DOCXs, PPTXs etc., then you don’t need to configure your SharePoint server for that to work. All that you need is to install recent enough LibreOffice (v.5.3+), and configure it at installation time to open MS Office files.

But if you choose either first method (ActiveX), or second method with coexisting LibreOffice/MS Office workstations, then you will need to configure SharePoint server for that. In both cases, you will need to edit DOCICON.xml file, that  may be found in server’s %ProgramFiles%\Common Files\Microsoft Shared\Web Server Extensions\XX\TEMPLATE\XML. This is an XML file, and we should edit sub-elements of ByExtension element. Such sub-element has the following syntax:

<Mapping Key="odt" Value="icodt.png" EditText="LibreOffice" OpenControl="LOSPSupport.OpenDocuments" OpenApp="vnd.libreoffice.command"/>
  • Key = file extension
  • Value = icon file
  • EditText = Text on “Edit with application” UI button – required for edit option. Optional.
  • OpenControl = ActiveX OpenDocuments control name (currently IE 32-bit only). Optional.
  • OpenApp = custom URI scheme to handle this. Independent from and appears to have priority over OpenControl. Available in 2013 SP1. Optional.

You should use either OpenControl or OpenApp, depending on which integration method you have chosen. Do it for those extensions that you want to be handled by LibreOffice. Of course, you should backup the file prior to modifying it.

After you have made all necessary modifications, to activate the settings, you need to restart IIS. To do that, you may execute command iisreset from the server’s administrator command line.

That’s it, if you did everything right, LibreOffice should now seamlessly integrate with SharePoint website, and be automatically launched when you choose to open files from there, without downloading the file to local machine first.

This is the second of two posts that discuss the current state of SharePoint integration support in LibreOffice. Thank you for reading, and enjoy the best free office suite ever!