DALiuGE Data Component Developers Guide¶
This chapter describes what developers need to do to write a new data component that can be used as a Data Drop during the execution of a DALiuGE graph.
Different from most other frameworks DALiuGE makes data components first class entities in the context of a workflow. In fact data components, or rather the instances of data components, the Data Drops, are driving the execution of a workflow. Consequently DALiuGE graphs are showing both application and data components as graph nodes. Edges in DALiuGE graphs are symbolising event flow and not data flow. In fact most Data Drops just refer to their data payload using a URL. The Data Drop layer provides two main features:
Abstraction of the I/O interface particularities of the underlying data storage mechanism.
Implementation of the DALiuGE data state engine, which is the DALiuGE mechansim to drive the execution of the workflow graphs.