Send Event
Send Event: broadcasts a named event, with optional payload values, to every Receive Event listening on the same channel.
Event Sender fires an app-wide (or scoped) event when its sendEvent signal triggers. The event is identified by channelName; every Event Receiver with the same channel fires in response, wherever it lives in the component tree — no wires between them. Payload values are declared on the payload parameter (a list of names); each declared name becomes an input port whose current value travels with the event and appears as an output on the receivers. propagation narrows delivery (e.g. to parent components only) instead of broadcasting globally.
When to use it
Cross-cutting notifications where sender and receivers must stay decoupled: 'refresh now', 'user logged out', toast requests. For parent↔child communication prefer Component Inputs/Outputs; for shared state prefer Variables/Objects — events are moments, not state.
At a glance
| Category | Events |
| Type name | Event Sender |
| Available in | browser |
| SSR compatibility | safe |
| Provided by | noodl-viewer-react |
Inputs
Values
| Name | Type | Default | Description |
|---|---|---|---|
channelName | String (EventChannelName id) | `` | Name every Receive Event must match to hear this; nothing reports a name no receiver listens on |
payload | Stringlist | — | Names of the values to carry with the event; each becomes an input here and an output on every matching Receive Event |
propagation | Enum (global, parent, children, siblings) | global | How far the event travels: the whole app, or only the receivers above, below or beside this node |
Signals
| Name | Type | Default | Description |
|---|---|---|---|
sendEvent | Signal | — | Sends one event on Channel Name, after every payload input has settled |
Outputs
Signals
| Name | Type | Default | Description |
|---|---|---|---|
completed | Signal | — | Fires after every invocation, whatever the outcome — wire this to carry on regardless. Failure still fires and still carries its reason, so this cannot hide an error |
done | Signal | — | Fires once the event has been dispatched to every matching receiver |
Failure outputs
| Name | Type | Default | Description |
|---|---|---|---|
error | String | — | Why the last send failed, empty when the last send succeeded |
failure | Signal | — | Fires when the event could not be sent, which today means Channel Name was left empty |
Dynamic ports
This node's port list changes at runtime (runtime-discovered); the tables above may be incomplete for a given instance.
Payload input ports are defined by the "ports" parameter (the payload schema of the channel being sent on).
Ports at runtime
Runtime-discovered inputs: each name listed in payload is registered as an input port on demand. The payload port set is defined entirely by that parameter and cannot be known without it.
Patterns
- Toolbar button → Send Event('RefreshRequested'); data panels each hold a Receive Event that re-runs their query.
- Payload-carrying events for 'open item X' style requests, received where the detail view lives.
Watch out for
- Using events as a data bus for continuously-changing values — receivers only see values at event time; use a Variable/Object for state.
- Free-typing slightly different channel names at each end; channel matching is exact.
Examples
Decoupled communication with Send Event / Receive Event
Events carry a signal (and optional payload values) between components with no wire between them: every Receive Event listening on the same channelName fires when a Send Event on that channel sends. Here a toolbar button broadcasts 'RefreshRequested', and a separate component re-runs its data fetch when it receives the event. Use events when the sender must not know who reacts; for parent↔child data flow prefer Component Inputs/Outputs.
Related nodes
Receive Event, Component Outputs, Variable, Object
This page is generated from node-catalog-enriched.json. Do not edit it by hand — run npm run docs:nodes to regenerate, and fix the source enrichment instead.