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Router component

Router component

Examines the message content and routes the message onto a different flow branch based on data contained in the message.

This component implements the The Content-Based Router pattern from Enterprise Integration Patterns (EIP).

Latest changelog

0.0.3 (December 24, 2019)

  • Update sailor version to 2.5.4

To see the full changelog please use the following link.

Triggers

This component has no trigger functions. This means it will not be accessible to select as a first component during the integration flow design.

Actions

  • Route - this action is responsible for performing the only function of the component, which is described in the header.

Environment Variables

LOG_LEVEL - trace debug info warning error controls logger level

How it works?

Here is the sample integration flow with CBR inside it:

{
    "data": {
        "attributes": {
            "name": "CBR Test",
            "type": "ordinary",
            "graph": {
                "nodes": [
                    {
                        "command": "platform/webhook:receive@latest",
                        "fields": {
                            "payload": "test"
                        },
                        "id": "in"
                    },
                    {
                        "command": "platform/router:route@latest",
                        "id": "router"
                    },
                    {
                        "command": "platform/code:execute@latest",
                        "fields": {
                            "code": "this.logger.info('one');emitter.emit('data',msg)"
                        },
                        "id": "one"
                    },
                    {
                        "command": "platform/code:execute@latest",
                        "fields": {
                            "code": "this.logger.info('two');emitter.emit('data',msg)"
                        },
                        "id": "two"
                    },
                    {
                        "command": "platform/code:execute@latest",
                        "fields": {
                            "code": "this.logger.info('default');emitter.emit('data',msg)"
                        },
                        "id": "default"
                    }
                ],
                "edges": [
                    {
                        "source": "in",
                        "target": "router"
                    },
                    {
                        "config": {
                            "condition": "$number(test) > 10"
                        },
                        "source": "router",
                        "target": "one"
                    },
                    {
                        "config": {
                            "condition": "$number(test) > 20"
                        },
                        "source": "router",
                        "target": "two"
                    },
                    {
                        "source": "router",
                        "target": "default"
                    }
                ]
            }
        },
        "type": "flow"
    }
}

The content based router (CBR) component has a single input and multiple outputs (edges). Outgoing edge from CBR component should have a configuration property called condition that defines a JSONata expression. Expression on each edge is validated based on message that arrived to the CBR component. If condition is evaluated to true then a copy of the message is sent to the component connected to the outgoing edge.

If condition is not defined on the outgoing edge, then this edge considered to be default edge. Default edge will get all messages that didn’t matched any other edges. Please note - CBR component may only have a single default edge. Multiple default edges will fail validation of elastic.io API.

Now let us examine our sample from above:

  • Incoming webhook has a message like
    {
        "test":"12345"
    }
  • As you can see CBR component has 3 outgoing edges, conditions are
  • $number(test) > 10 for edge that is connected to step ID one
  • $number(test) > 30 for edge that is connected to step ID two
  • Last edge has no condition, therefore a default edge connected to step default