1. A method for determining if a first component can be connected to a second component for inclusion in a processing graph, comprising: accessing a first component description, the first component description describing an output object of the first component with a set of tags; accessing a second component description, the second component description describing an input condition of the second component with a set of tags; determining that the first component can be connected to the second component if the set of tags describing the output object includes all tags describing the input condition; and including the first and second connected components in a processing graph if they are connected to each other, wherein information is propagated from an input port of the second component to an output port of the second component by defining a sticky tag as a label for automatically propagating tags, wherein if a sub-tag of the sticky tag appears in a description of the output object of the first component, the sticky tag is added to the description of an object to be output from the output port of the second component.