@dangerouslyRemoveOn

@dangerouslyRemoveOn complements the @removeOn directive.

There are cases where you might want your projection to react to events from multiple topics. In such cases, you can use the @dangerouslyRemoveOn directive to remove data from the projection based on events from multiple topics.

Possible Inconsistencies

Using @dangerouslyRemoveOn can lead to inconsistencies in your projection. The order of events is only guaranteed within a single topic, not across multiple topics. Therefore it might happen that all events of topic A are applied before all events of topic B, even if the event from topic B was published before the event from topic A. If this is not a problem for your projection, you can use @dangerouslyRemoveOn to remove data from the projection based on events from multiple topics.

Example

If you want to react to actions in several topics, you can't just use the @removeOn directive. You have to use the @dangerouslyRemoveOn directive.

In the following case the removeUser event will remove data identified by the value of its id payload field from the projection.

user.graphql

type User
    @removeOn(
        on: {
            topic: "userManagement"
            eventTypes: ["removeUser"]
        }
        identifyBy: { payload: ["id"] }
    )
    @dangerouslyRemoveOn(
        on: {
            topic: "roleManagement"
            eventTypes: ["removeUser"]
        }
        identifyBy: { payload: ["userId"] }
    ) {
    // ...
}

As you can see in this example, the removeUser events from two different topics are used to remove data from the projection.

For more information, please see the removeOn directive.

@dangerouslyRemoveOn

Example

On this page