Start/end nodes

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Start node

The start node represents the beginning of a process and it is mandatory to add one when creating a process.

A process can have one or more start nodes. If you defined multiple start nodes, each should have a start condition value configured. When starting a new process instance the desired start condition should be used.

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Configuring a start node

Node configuration is done by accessing the Node Config tab. You have the following configuration options for a start node:

• General Config
• Start condition

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General Config

• Node name - the name of the node
• Can go back - switching this option to true will allow users to return to this step after completing it

• Swimlane - choose a swimlane (if there are multiple swimlanes on the process) to make sure only certain user roles have access only for certain process nodes- if there are no multiple swimlanes, the value is Default
• Stage - assign a stage to the node

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Start condition

The start condition should be set as a string value. This string value will need to be set on the payload for the start process request on the startCondition key.

To test the start condition, we can send a start request via REST:

POST {{processUrl}}/api/process/{{processName}}/start
{
    "startCondition": "PF"
}

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Error handling on start condition

If a request is made to start a process with a start condition that does not match any start node, an error will be generated. Let’s take the previous example and assume we send an incorrect value for the start condition:

POST {{processUrl}}/api/process/{{processName}}/start
{
    "startCondition": "PJ"
}

A response with the error code bad request and title Start node for process definition not foundwill be sent in this case:

{
    "entityName": "ai.flowx.process.definition.domain.NodeDefinition",
    "defaultMessage": "Start node for process definition not found.",
    "errorKey": "error.validation.process_instance.start_node_for_process_def_missing",
    "type": "https://www.jhipster.tech/problem/problem-with-message",
    "title": "Start node for process definition not found.",
    "status": 400,
    "message": "error.validation.process_instance.start_node_for_process_def_missing",
    "params": "ai.flowx.process.definition.domain.NodeDefinition"
}

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End node

An end node is used to mark where the process finishes. When the process reaches this node, the process is considered completed and its status will be set to Finished.

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Configuring an end node

Multiple end nodes can be used to show different end states. The configuration is similar to the start node.