Attribute Definition Dependencies
In order to use attributes from data connectors or other definitions you need to make sure those dependencies are resolved before this definition is called.
If your definition depends on a data connector create a child element, of the main definition element, called DataConnectorDependency and give it an attribute of requires whose value is the id of the data connector this definition depends on.
If your definition depends on another definition create a child element, of the main definition element, called AttributeDependency and give it an attribute of requires whose value is the id of the definition this definition depends on.