extract_event_types.js

// copyright Etienne Rossignon - 2017
var makeNodeId = opcua.makeNodeId;
var ObjectTypeIds = opcua.ObjectTypeIds;

function getAllEventTypes(session,callback)
{
    var baseNodeId = makeNodeId(ObjectTypeIds.BaseEventType);

    var q = new async.queue(function(task,callback) {

        _getAllEventTypes(task.nodeId,task.tree,function(err){
            if(err){return callback(err);}
            callback(null,result);
        });

    });
    function _getAllEventTypes(baseNodeId,tree,callback) {

        //xx console.log(" exploring elements,",element.nodeId.toString());
        var browseDesc1 = {
            nodeId: baseNodeId,
            referenceTypeId: opcua.resolveNodeId("HasSubtype"),
            browseDirection: opcua.browse_service.BrowseDirection.Forward,
            includeSubtypes: true,
            nodeClassMask: opcua.browse_service.NodeClassMask.ObjectType, // Objects
            resultMask: 63
        };

        var nodesToBrowse = [browseDesc1];
        session.browse(nodesToBrowse,function(err,results){
            // to do continuation points
            results[0].references.forEach(function(reference) {
                var subtree = { nodeId: reference.nodeId.toString() };
                tree[reference.browseName.toString()] = subtree;
                q.push({nodeId: reference.nodeId, tree: subtree});
            });

            callback();
        });
    }
    var result ={};

    q.push({nodeId: baseNodeId,tree: result});

    q.drain = function( ) {
        callback(null,result);
    };

}