Described is a system and method for creating a runtime connection interface for attributes and element tags defined declaratively in a subclass within a markup document. These subclass attributes may define an event, and the element tags scoped inside a subclass may define a resource, and the like, associated with the subclass being defined within the markup document. During runtime, the runtime connection interface allows a parser to make direct calls to connect the subclass attribute with an associated instance of the subclass. The system and method include identifying an attribute or element tag defined within a markup document. The attribute or element tag is associated with a target element being declaratively defined within the markup document. The attribute may define an event, and an element tag resource, and the like, associated with a target element that is also declared within the subclass in the markup. An identifier for the target element is determined. An executable assembly is generated that provides a runtime connection mechanism that is configured to attach an item associated with the attribute or element tag to an instance of the target element during runtime. Thus, in accordance with the present invention, an event handler that is declaratively defined within markup is compiled in a manner such that during runtime a direct call hooks up the event handler with the instance of the target element.