Home | Table of Contents | Design Patterns | CloverETL 4.6.1
--- | --- | ---
Prev | Subgraphs | Next

# Chapter 45. Design Patterns

## Readers

Subgraphs with no edge connected to SubgraphInput component do not declare any input ports, therefore cannot receive input data so will likely be used as Readers .

Figure 45.1. Subgraph - Reader

## Writers

Subgraphs with no edge connected to SubgraphOutput component provide no output ports, therefore cannot produce any data so will likely be used as Writers .

Figure 45.2. Subgraph - Writer

## Transformers

Subgraph having connected both components ( SubgraphInput and SubgraphOutput ) is essentially a Transformer .

Figure 45.3. Subgraph - Transformer

## Executors

Subgraphs with no edge connected to SubgraphInput or SubgraphOutput components can be used as utility Executors . As they cannot be connected to other components in parent graph the execution of subgraphs without ports is controlled via Phases .

Figure 45.4. Subgraph - Executor

Prev | Up | Next
Developing Subgraphs | Home | Table of Contents | Jobflow