Event Trigger Plugin

For the implementation of diverse processes, HIP CDR has the possibility to create event triggers. For this purpose, criteria can be flexibly defined and linked to actions. For example, when new data is transferred to the platform, the system can automatically check which type of examination is involved and whether a threshold value has been exceeded. This function can be used to support the extraction of data for secondary use or to asynchronously information systems about the creation of specific data points, for example an order. For this purpose, the patient ID and selected values can be send to a receiving system. It is also possible to create a rule to forward all incoming data to an external data warehouse. By supporting http requests and Kafka messages, different systems can be connected via event triggers

../../../_images/event_trigger_diagram.png

The event-trigger plugin allows to hook into composition creation/update. The hook is defined by an event-trigger which can run before or after the internal database transaction has completed.

The plugin supports several mechanisms to propagate a event-trigger message.

HTTP
AMQP via RabbitMQ
Kafka
Java Logging

Parameters / Environment Variables

Parameter	Env Variable	Usage	Example
spring.rabbitmq.host	SPRING_RABBITMQ_HOST	RabbitMQ host address	127.0.0.01
spring.rabbitmq.port	SPRING_RABBITMQ_PORT	RabbitMQ host port	5672
spring.rabbitmq.username	SPRING_RABBITMQ_USERNAME	RabbitMQ Username	guest
spring.rabbitmq.password	SPRING_RABBITMQ_PASSWORD	RabbitMQ Password	guest
spring.rabbitmq.virtual-host	SPRING_RABBITMQ_VIRTUALHOST	RabbitMQ Virtual Host to use	/
eventTrigger.kafka.activate	EVENTTRIGGER_KAFKA_ACTIVATE	Activate Support for Kafka	true
spring.kafka.bootstrap-servers	SPRING_KAFKA_BOOTSTRAPSERVERS	Define Kafka Bootstrap Server	localhost:9092
Eventtrigger.workers	EVENTTRIGGER_WORKERS	the number of executor pool workers to use when create / update events happen. Increasing the workers number means multiple triggers can be evaluated in parallel.	8

Event Trigger REST API

A REST API allows to manage Triggers using Create, Update and Delete operations.

Create Event Trigger

POST {{ehrbase-url}}/ehrbase/plugin/event-trigger/service

Create an Event Trigger in CDR Base

Example request:

POST /ehrbase/plugin/event-trigger/service HTTP/1.1
Host: localhost:8080
Accept: application/json, text/javascript
Content-Type: application/json

{
    "id": "simple_test_trigger_bp.v1",
    "state": "active",
    "author": {
        "date": "2022-08-25T12:40:26.945Z",
        "name": "Alexandru Vidrean",
        "email": "alexandru.vidrean.ext@vitagroup.ag",
        "organisation": "VitaGroup AG"
    },
    "definition": {
        "mode": "AFTER",
        "rules": [
            {
                "diastolic": {
                    "when": {
                        "aql": "select e/ehr_id/value as ehr_id, c/uid/value as composition_id, o/data[at0001]/events[at0002]/data[at0003]/items[at0004]/value as diastolic from EHR e contains OBSERVATION o[openEHR-EHR-OBSERVATION.sample_blood_pressure.v1] AND COMPOSITION c where o/data[at0001]/events[at0002]/data[at0003]/items[at0004]/value/magnitude > 140"
                    },
                    "then": [
                        {
                            "logEvent": {
                                "command": "notify",
                                "channel": "logger"
                            }
                        },
                        {
                            "amqpPublish": {
                                "command": "publish",
                                "channel": "amqp",
                                "exchange": "demo-exchange",
                                "routing-key": "*"
                            }
                        },
                        {
                            "httpPost": {
                                "command": "notify",
                                "channel": "http",
                                "url": "http://localhost:1080/demo"
                            }
                        }
                    ]
                }
            }
        ]
    }
}

Example response:

HTTP/1.1 200 OK
Vary: Accept

Status Codes:

200 OK – no error
500 Internal Server Error – internal system error

The following attributes need to be set inside the body of the HTTP request:

Table 7: Event Trigger Request Attributes
Attribute	Meaning	Example
ID	Identifier of the Event Trigger. It is recommended to follow semantic versioning.	blood_pressure_trigger.v1
Language	Language of the event trigger	ISO_639-1::en
State	Indicates if the event trigger is active or inactive. Inactive triggers will not be fired.	„active“ / „inactive“
author	Information about the author of the event trigger. Note that the date needs to be provided explicitly by the client	“John Doe”
Definition.mode	Indicates when the Event Trigger is fired. For now, Event Triggers in EHRbase can only be fired after the Transaction that stored the composition has finished successfully	AFTER
Definition.rules	Provide one or more rules that are part of the Event Trigger logics	high_diastolic_pressure
Definition.rules.{rulename}.when.aql	Provide an AQL query. The AQL query will only be executed on the single composition that just has been stored. Use the SELECT field to select the elements of interest (or objects or the whole composition) and the WHERE clause to define criteria. The Event Trigger will be executed if the result of the AQL query in non-empty.	“SELECT c/uid/value from COMPOSITION c CONTAINS OBSERVATION o[openEHR-EHR-OBSERVATION.blood_pressure.v2]”
Definition.rules.{rulename}.then.notify	Attributes that are used for publishing a message using AMQP or HTTP	RabbitMQ: ““command””: “”publish””,” “””channel””: “”amqp””,” “””exchange””: “”etexchange””,” “””routing-key””: “”et””” Kafka: “””command””: “”publish””,” “””channel””: “”kafka””,” “””topic””: “”myTopic””” HTTP: “””command””: “”notify””,” “””channel””: “”http””,” “””url””: “”https://ptsv2.com/t/bwn4g-1656672291/post”””
Definition.rules.{rulename}.then.log	Attributes to define a logging event	“””command””: “”notify””,” “””channel””: “”logger”””

Retrieve Event Trigger

GET {{ehrbase-url}}/ehrbase/plugin/event-trigger/service/{{event_trigger_id}}

Retrieves an Event Trigger by providing its UUID.

Example request:

GET /ehrbase/plugin/event-trigger/service/3f2266c6-4eb2-47a3-9a83-6c7ace470fef HTTP/1.1
Host: localhost:8080

Example response:

HTTP/1.1 200 OK
Vary: Accept

[
    {
        "uuid": "1bd0f5b8-ced1-4412-bde9-520cd82e41ba",
        "id": "test_trigger_bmlowgpddd.v0",
        "language": {
            "original_language": "ISO_639-1::en"
        },
        "state": "active",
        "author": {
            "date": null,
            "name": "John Doe",
            "email": "info@vitagroup.ag",
            "organisation": "VitaGroup AG"
        },
        "definition": {
            "mode": "AFTER",
            "rules": [
                {
                    "high diastolic": {
                        "when": {
                            "aql": "select c/uid/value as diastolic from EHR e contains COMPOSITION c"
                        },
                        "then": [
                            {
                                "notify": {
                                    "command": "publish",
                                    "channel": "amqp",
                                    "exchange": "etexchange",
                                    "routing-key": "et"
                                }
                            },
                            {
                                "log": {
                                    "command": "notify",
                                    "channel": "logger"
                                }
                            }
                        ]
                    }
                }
            ],
            "pre_condition": []
        }
    }
]

Status Codes:

200 OK – Event Trigger was successfully activated / deactivated.
404 Not Found – No Event Trigger with given UUID was found.
500 Internal Server Error – Internal system error.

Retrieve all Event Triggers

GET {{ehrbase-url}}/ehrbase/plugin/event-trigger/service/

Retrieves all Event Triggers

Example request:

GET /ehrbase/plugin/event-trigger/service/ HTTP/1.1
Host: localhost:8080

Example response:

HTTP/1.1 200 OK
Vary: Accept

[
    {
        "uuid": "1bd0f5b8-ced1-4412-bde9-520cd82e41ba",
        "id": "test_trigger_bmlowgpddd.v0",
        "language": {
            "original_language": "ISO_639-1::en"
        },
        "state": "active",
        "author": {
            "date": null,
            "name": "John Doe",
            "email": "info@vitagroup.ag",
            "organisation": "VitaGroup AG"
        },
        "definition": {
            "mode": "AFTER",
            "rules": [
                {
                    "high diastolic": {
                        "when": {
                            "aql": "select c/uid/value as diastolic from EHR e contains COMPOSITION c"
                        },
                        "then": [
                            {
                                "notify": {
                                    "command": "publish",
                                    "channel": "amqp",
                                    "exchange": "etexchange",
                                    "routing-key": "et"
                                }
                            },
                            {
                                "log": {
                                    "command": "notify",
                                    "channel": "logger"
                                }
                            }
                        ]
                    }
                }
            ],
            "pre_condition": []
        }
    },
    {
        "uuid": "1bd0f5b8-ced1-4412-bde9-520cd82e41ba",
        "id": "test_trigger_bmlowgpddd.v0",
        "language": {
            "original_language": "ISO_639-1::en"
        },
        "state": "active",
        "author": {
            "date": null,
            "name": "John Doe",
            "email": "info@vitagroup.ag",
            "organisation": "VitaGroup AG"
        },
        "definition": {
            "mode": "AFTER",
            "rules": [
                {
                    "high diastolic": {
                        "when": {
                            "aql": "select c/uid/value as diastolic from EHR e contains COMPOSITION c"
                        },
                        "then": [
                            {
                                "notify": {
                                    "command": "publish",
                                    "channel": "amqp",
                                    "exchange": "etexchange",
                                    "routing-key": "et"
                                }
                            },
                            {
                                "log": {
                                    "command": "notify",
                                    "channel": "logger"
                                }
                            }
                        ]
                    }
                }
            ],
            "pre_condition": []
        }
    }
]

Status Codes:

200 OK – Event Trigger was successfully activated / deactivated.
404 Not Found – No Event Trigger with given UUID was found.
500 Internal Server Error – Internal system error.

Update Event Trigger

PUT {{ehrbase-url}}/ehrbase/plugin/event-trigger/service/{{event_trigger_id}}

Activates or deactives an event trigger based on the event-trigger uid

Example request:

PUT /ehrbase/plugin/event-trigger/service/3f2266c6-4eb2-47a3-9a83-6c7ace470fef?activate=false HTTP/1.1
Host: localhost:8080

Example response:

HTTP/1.1 200 OK
Vary: Accept

Status Codes:

200 OK – Event Trigger was successfully activated / deactivated
404 Not Found – No Event Trigger with given uuid was found
500 Internal Server Error – internal system error.

Delete Event Trigger

DELETE {{ehrbase-url}}/ehrbase/plugin/event-trigger/service/{{event_trigger_id}}

Deletes an event trigger based on the event-trigger uid

Example request:

DELETE /ehrbase/plugin/event-trigger/service/3f2266c6-4eb2-47a3-9a83-6c7ace470fef HTTP/1.1
Host: localhost:8080

Example response:

HTTP/1.1 200 OK
Vary: Accept

Status Codes:

200 OK – Event Trigger was successfully deleted
404 Not Found – No Event Trigger with given uuid was found
500 Internal Server Error – internal system error.