Prevent VSTO Office Customisation installer prompt from appearing when Opening a document - vsto

Question

I have developed a VSTO 4.0 Document Customisation for a custom Template which works fine and installs using ClickOnce.
However, one of the requirements I have is that the resultant documents, being the resultant .docx files, are shared with users outside of my organisation and I DON'T want them to be prompted by VSTO to install the customisation.
The external users should be able to open the document without any VSTO prompts and treat it like a usual Word document, and when the document is saved by the external user and sent back, I can open the document and the the VSTO customisation will work as expected.
This is a usability scenario where a document needs to be collaborated on by my organisation and an external organisation, but I can't expect the external organisation to install the VSTO customisation. They will typically just insert text, pictures and add review comments.
Is there any way that I can achieve this scenario?
BTW, using a Web Addin for Office 365 is not a feasible option at this stage as some of the customisation requirements cannot be achieved with the Word Javascript API.

Answer 1

You need to remove the link from the VSTO document before making it available to outside people. And when the document comes back you can link the customization back to it.
There's an entire MSDN article on the topic, as well as a blog article.
In a nutshell, there are two ways this can be done: from within the opened document or on the closed document.
Run the Document.RemoveCustomization method, which can be assigned to a button in the Ribbon customization, for example. This removes the links stored in Custom Document properties to the VSTO code (which is how the document, itself, finds the code when it opens), as well as any cached data.
Use the ServerDocument.RemoveCustomization method, which essentially does the same thing.
ServerDocument.RemoveCustomization(documentPath);
Re-attaching can only be done via ServerDocument.AddCustomization, logically enough.
string deployManifestPath = System.Environment.GetFolderPath(
Environment.SpecialFolder.Desktop)
+ #"\Publish\WordDocument1.vsto";
Uri deploymentManifestUri = new Uri(deployManifestPath);
ServerDocument.AddCustomization(documentPath, deploymentManifestUri);