Data Store Node

Overview

Data Store Node represents a storage mechanism in an Activity. Every Token that has passed to it is stored and always passed on to output Flows - as a result those Flows are considered always activated.

A Data Store Node consists of:

• Name, uniquely identifying the Data Store Node within the Activity,
• Incoming Flows, passing input Tokens into the node,
• Outgoing Flows, passing output Tokens outside the node.

Definition

In UML, a Data Store Node is represented as a rectangle:

flowchart

initial@{ shape: circle, label: " " }
initial --> producer
producer(DataProducer)
producer -->|Data| store
store[DataStore]
store -->|Data| processor
processor(DataProcessor)
time@{ shape: hourglass, label: "Every hour" }
time --> processor

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Equivalent Stateflows notation of a Data Store Node:

Lambda style

    /* fragment of Activity definition */
    .AddInitial(b => b
        .AddControlFlow("DataProducer")
    )
    .AddAction("DataProducer",
        async c => {
            /* logic that produces data */
        },
        b => b.AddFlow<Data>(DataStoreNode.Name)
    )
    .AddDataStore(b => b
        .AddFlow<Data>("DataProcessor")
    )
    .AddAction("DataProcessor",
        async c =>
        {
            /* processing logic */
        }
    )
    .AddTimeEventAction<EveryHour>(b => b
        .AddControlFlow("DataProcessor")
    )

Using lambda style means that the Data Store Node is defined by its name and logic, with flows specified using a fluent builder.

Typed style

    public class StoreData : IDataStoreNode
    {
        public async Task ExecuteAsync()
        {
            /* logic to store data */
        }
    }

    public class NextNode : IActionNode
    {
        public async Task ExecuteAsync()
        {
            /* subsequent logic */
        }
    }

    /* fragment of Activity definition */
    .AddDataStore<StoreData>(b => b
        .AddFlow<Data, NextNode>()
    )
    .AddAction<NextNode>()

Using typed style means that the Data Store Node is represented by a class implementing the IDataStoreNode interface.