<ref>- Resolve a reference to another part of the document using a dot key path
<ifset>- Checks if a reference is null. If so, replace the object by null.
<switch>- Choose one of the child properties based on a property in the document
<merge>- Merge a set of objects
<enrich>- Enrich an object with extra data by matching properties
<dateformat>- Takes a date and a format (defaults to
Y-m-d) and formats the accordingly. Optionally you can set the timezone if you wish to output timezone information.