Creating a Flow

Every app has at least one flow. Each flow can be attached to one or more triggers. You have the option to begin by creating a blank flow (flow without a trigger) too and attaching the flow to one or more triggers at a later time. Use the +Create link on the app page to create the first flow in an app. If there are existing flows in an app, click the Create button to create additional flows attached to a new trigger or to create a flow that is attached to the existing trigger, hover over the trigger and click New flow.

Prerequisites

Before creating a flow for connectors, make sure that you have created the necessary connections.

Important: If an app has multiple triggers that require a port to be specified, for example REST and/or GraphQL triggers, make sure that the port number is unique for each trigger. Two triggers in the same app cannot run on the same port.

Note: A flow can be attached to multiple triggers. For such flows, you cannot disable a trigger, specify a particular trigger to execute, or specify the order in which the triggers execute. When a flow executes, all triggers get initialized in the order that they appear within the flow.

When using the Lambda, S3, or Gateway triggers, keep the following in mind:

An app can contain only one Lambda trigger. An app that has a Lambda trigger cannot contain any other triggers including another Lambda trigger. Also, the Lambda trigger supports only one handler per trigger so it can have only one flow attached to it. However, the apps that contain a Lambda trigger can contain blank flows that can serve as subflows for the flow attached to the Lambda trigger.
You can have only one S3 trigger in an app. An app that has an S3 trigger cannot contain any other triggers including another S3 trigger. The S3 trigger supports multiple handlers (flows), so you can have multiple flows in the app that are attached to the same S3 trigger. You can also have blank flows in the app which can serve as subflows for the flows that are attached to the S3 trigger.
You can have only one Gateway trigger in an app. An app that has an Gateway trigger cannot contain any other triggers including another Gateway trigger. The Gateway trigger supports multiple handlers (flows), so you can have multiple flows in the app that are attached to the same Gateway trigger. You can also have blank flows in the app which can serve as subflows for the flows that are attached to the Gateway trigger.

The output of a trigger provides the input to the flow. Hence, it must be mapped to the flow input. In the absence of a trigger, when creating a flow, there must be a well-defined contract within the flow which specifies the input to the flow and the output expected after the flow completes execution. You define this contract in the Flow Inputs & Outputs dialog. The Flow Inputs & Ouputs contract works as a bridge between the flow and the trigger, hence every trigger has to be configured to map its output to the Input parameters defined in Flow Inputs & Ouputs.

Note: A Return activity is not added by default. Depending on your requirements, you must add the Return activity manually. For example, if any trigger needs to send a response back to a server, its output must be mapped to the output of the Return activity in the flow.

Follow these steps to create a flow:

Procedure

Click an app name on the Apps page in TIBCO Cloud Integration - Flogo (PAYG) to open its page.
Click the +Create if this is the first flow in the app. If one or more flows exist, click the Create button.
The Create flows and triggers dialog opens.
Enter a name for the flow in the Name text box.
Flow names within an app must be unique. An app cannot contain two flows with the same name.
Optionally, enter a brief description of what the flow does in the Description text box. The New flow button is selected by default.
To create a flow from a Swagger specification, refer to Using a Swagger Specification for details. To create a flow from a GraphQL schema, refer to Using a GraphQL Schema for details. To create a flow from a gRPC Protobuf, see Using gRPC.
Click Create.
You will be prompted to select one of the following options:
- Start with a trigger - If you know the trigger with which you want to activate the flow, select this option. If this is the first flow, the Trigger catalog opens. Select a trigger from the catalog. Refer to the appropriate section under Starting with a Trigger for more details on the the type of trigger that you want to create. If there are existing flows attached to triggers, you get a dialog which gives you an option to either use an existing trigger or use a new trigger that has not been used in an existing flow within the app.
- Configure flow inputs and outputs - Select this option if you know the algorithm for the flow, but do not yet know the circumstances that will cause the flow to execute. It will create a blank flow that is not attached to any trigger. Flow inputs and outputs create a contract between the trigger and the flow. When you create a trigger, you must map the output of the trigger to the input to the flow. This contract serves as a bridge between the trigger and the flow. You have the option to attach your flow to one or more triggers at any later time after the flow has been created.
A flow gets created and it is attached to the selected trigger.