JavaScript access to the versionHistory property?

As we transition to the new Hyland Community, some post links may be temporarily disrupted as we finalize redirects. We apologize for the inconvenience and are working to resolve this as quickly as possible. Details.

martin_cowie

I'm trying in vain to find a means of examining the version history of a document, using the Javascript API. All I need is the number versions, and the size of each version.

The documentation suggests that FreeMarker can access a nodes 'versionHistory' node, but the JavaScript certainly cannot.

I'm in the process of writing a disk-usage tool, and not having visibility over the document history is a teensy bit of a sticking point 🙂

Can anyone tell me where I'm going wrong?

M.

martin_cowie

Found it! The solution was use the power of the Rhino Javascript engine to access bits of its Java environment.

The ScriptNode object has a protected 'services' field. Once that can be accessed, everything else falls into place …

var PROP_CONTENT = Packages.org.alfresco.model.ContentModel.PROP_CONTENT;
var versionService = null;
var nodeService = null;

function getServices( doc )
{
   // *BEWARE* - HERE BE DRAGONS
   var servicesField = doc.getClass().getDeclaredField( "services" );
   servicesField.setAccessible( true ); // ick - yuck - nasty - but necessary
   var serviceRegistry = servicesField.get( doc );

   versionService = serviceRegistry.getVersionService();
   nodeService = serviceRegistry.getNodeService();
}

function getHistory( doc )
{
   return versionService.getVersionHistory( doc.nodeRef ).getAllVersions().toArray();
}

function getVersionSize( version )
{
   return nodeService.getProperty( version.getFrozenStateNodeRef(), PROP_CONTENT ).getSize();
}
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Once getServices() is called with a ScriptNode object, we can then call getHistory() to get a Java array of Version objects. Given a Version object, getVersionSize() can be called to get the size of its content.

It's a bit ugly, but a worthy demonstration of Rhinos power.

M.