Data Subscriptions: Creation API Overview

Subscription creation is accessible through DocumentStore's subscriptions property, of type DocumentSubscriptions:

store.subscriptions.create(clazz, [database]);
store.subscriptions.create(options, [database]);

store.subscriptions.createForRevisions(clazz, [database]);
store.subscriptions.createForRevisions(options, [database]);

• Functions definition part, like in ordinary RQL. Those functions can contain any javascript code, and also supports load operations.

• From statement, defining the documents source, ex: from Orders. The from statement can only address collections, therefore, indexes are not supported.

• Where statement describing the criteria according to which it will be decided to either send the documents to the worker or not. Those statements supports either RQL like equality operations (=, ==) ,
  plain JavaScript expressions or declared function calls, allowing to perform complex filtering logic.
  The subscriptions RQL does not support any of the known RQL searching keywords.

• Select statement, that defines the projection to be performed. The select statements can contain function calls, allowing complex transformations.

• Include statement allowing to define include path in document.

from Orders as o
where o.Lines[].Product = "products/1-A"

declare function filterLines(doc, productId)
{
    if (!!doc.Lines){
        return doc.Lines.filter(x=>x.Product == productId).length >0;
    }
    return false;
}

from Orders as o
where filterLines(o, "products/1-A")