/* eslint-disable n8n-nodes-base/node-filename-against-convention */
import type { Message } from 'amqplib';
import type {
IDeferredPromise,
IExecuteResponsePromiseData,
INodeProperties,
INodeType,
INodeTypeDescription,
IRun,
ITriggerFunctions,
ITriggerResponse,
} from 'n8n-workflow';
import { NodeConnectionType, NodeOperationError } from 'n8n-workflow';
import { rabbitDefaultOptions } from './DefaultOptions';
import { MessageTracker, rabbitmqConnectQueue, parseMessage } from './GenericFunctions';
import type { TriggerOptions } from './types';
export class RabbitMQTrigger implements INodeType {
description: INodeTypeDescription = {
displayName: 'RabbitMQ Trigger',
name: 'rabbitmqTrigger',
icon: 'file:rabbitmq.svg',
group: ['trigger'],
version: 1,
description: 'Listens to RabbitMQ messages',
eventTriggerDescription: '',
defaults: {
name: 'RabbitMQ Trigger',
},
triggerPanel: {
header: '',
executionsHelp: {
inactive:
"While building your workflow, click the 'listen' button, then trigger a Rabbit MQ event. This will trigger an execution, which will show up in this editor.
Once you're happy with your workflow, activate it. Then every time a change is detected, the workflow will execute. These executions will show up in the executions list, but not in the editor.",
active:
"While building your workflow, click the 'listen' button, then trigger a Rabbit MQ event. This will trigger an execution, which will show up in this editor.
Your workflow will also execute automatically, since it's activated. Every time a change is detected, this node will trigger an execution. These executions will show up in the executions list, but not in the editor.",
},
activationHint:
"Once you’ve finished building your workflow, activate it to have it also listen continuously (you just won’t see those executions here).",
},
inputs: [],
outputs: [NodeConnectionType.Main],
credentials: [
{
name: 'rabbitmq',
required: true,
},
],
properties: [
{
displayName: 'Queue / Topic',
name: 'queue',
type: 'string',
default: '',
placeholder: 'queue-name',
description: 'The name of the queue to read from',
},
{
displayName: 'Options',
name: 'options',
type: 'collection',
default: {},
placeholder: 'Add option',
options: [
{
displayName: 'Content Is Binary',
name: 'contentIsBinary',
type: 'boolean',
default: false,
description: 'Whether to save the content as binary',
},
{
displayName: 'Delete From Queue When',
name: 'acknowledge',
type: 'options',
options: [
{
name: 'Execution Finishes',
value: 'executionFinishes',
description:
'After the workflow execution finished. No matter if the execution was successful or not.',
},
{
name: 'Execution Finishes Successfully',
value: 'executionFinishesSuccessfully',
description: 'After the workflow execution finished successfully',
},
{
name: 'Immediately',
value: 'immediately',
description: 'As soon as the message got received',
},
{
name: 'Specified Later in Workflow',
value: 'laterMessageNode',
description: 'Using a RabbitMQ node to remove the item from the queue',
},
],
default: 'immediately',
description: 'When to acknowledge the message',
},
{
displayName: 'JSON Parse Body',
name: 'jsonParseBody',
type: 'boolean',
displayOptions: {
hide: {
contentIsBinary: [true],
},
},
default: false,
description: 'Whether to parse the body to an object',
},
{
displayName: 'Only Content',
name: 'onlyContent',
type: 'boolean',
displayOptions: {
hide: {
contentIsBinary: [true],
},
},
default: false,
description: 'Whether to return only the content property',
},
{
displayName: 'Parallel Message Processing Limit',
name: 'parallelMessages',
type: 'number',
default: -1,
displayOptions: {
hide: {
acknowledge: ['immediately'],
},
},
description: 'Max number of executions at a time. Use -1 for no limit.',
},
{
displayName: 'Binding',
name: 'binding',
placeholder: 'Add Binding',
description: 'Add binding to queu',
type: 'fixedCollection',
typeOptions: {
multipleValues: true,
},
default: {},
options: [
{
name: 'bindings',
displayName: 'Binding',
values: [
{
displayName: 'Exchange',
name: 'exchange',
type: 'string',
default: '',
placeholder: 'exchange',
},
{
displayName: 'RoutingKey',
name: 'routingKey',
type: 'string',
default: '',
placeholder: 'routing-key',
},
],
},
],
},
...rabbitDefaultOptions,
].sort((a, b) => {
if (
(a as INodeProperties).displayName.toLowerCase() <
(b as INodeProperties).displayName.toLowerCase()
) {
return -1;
}
if (
(a as INodeProperties).displayName.toLowerCase() >
(b as INodeProperties).displayName.toLowerCase()
) {
return 1;
}
return 0;
}) as INodeProperties[],
},
{
displayName:
"To delete an item from the queue, insert a RabbitMQ node later in the workflow and use the 'Delete from queue' operation",
name: 'laterMessageNode',
type: 'notice',
displayOptions: {
show: {
'/options.acknowledge': ['laterMessageNode'],
},
},
default: '',
},
],
};
async trigger(this: ITriggerFunctions): Promise {
const queue = this.getNodeParameter('queue') as string;
const options = this.getNodeParameter('options', {}) as TriggerOptions;
const channel = await rabbitmqConnectQueue.call(this, queue, options);
if (this.getMode() === 'manual') {
const manualTriggerFunction = async () => {
// Do only catch a single message when executing manually, else messages will leak
await channel.prefetch(1);
const processMessage = async (message: Message | null) => {
if (message !== null) {
const item = await parseMessage(message, options, this.helpers);
channel.ack(message);
this.emit([[item]]);
} else {
this.emitError(new Error('Connection got closed unexpectedly'));
}
};
const existingMessage = await channel.get(queue);
if (existingMessage) await processMessage(existingMessage);
else await channel.consume(queue, processMessage);
};
const closeFunction = async () => {
await channel.close();
await channel.connection.close();
return;
};
return {
closeFunction,
manualTriggerFunction,
};
}
const parallelMessages = options.parallelMessages ?? -1;
if (isNaN(parallelMessages) || parallelMessages === 0 || parallelMessages < -1) {
throw new NodeOperationError(
this.getNode(),
'Parallel message processing limit must be a number greater than zero (or -1 for no limit)',
);
}
let acknowledgeMode = options.acknowledge ?? 'immediately';
if (parallelMessages !== -1 && acknowledgeMode === 'immediately') {
// If parallel message limit is set, then the default mode is "executionFinishes"
// unless acknowledgeMode got set specifically. Be aware that the mode "immediately"
// can not be supported in this case.
acknowledgeMode = 'executionFinishes';
}
const messageTracker = new MessageTracker();
let closeGotCalled = false;
if (parallelMessages !== -1) {
await channel.prefetch(parallelMessages);
}
channel.on('close', () => {
if (!closeGotCalled) {
this.emitError(new Error('Connection got closed unexpectedly'));
}
});
const consumerInfo = await channel.consume(queue, async (message) => {
if (message !== null) {
try {
if (acknowledgeMode !== 'immediately') {
messageTracker.received(message);
}
const item = await parseMessage(message, options, this.helpers);
let responsePromise: IDeferredPromise | undefined = undefined;
let responsePromiseHook: IDeferredPromise | undefined =
undefined;
if (acknowledgeMode !== 'immediately' && acknowledgeMode !== 'laterMessageNode') {
responsePromise = await this.helpers.createDeferredPromise();
} else if (acknowledgeMode === 'laterMessageNode') {
responsePromiseHook =
await this.helpers.createDeferredPromise();
}
if (responsePromiseHook) {
this.emit([[item]], responsePromiseHook, undefined);
} else {
this.emit([[item]], undefined, responsePromise);
}
if (responsePromise && acknowledgeMode !== 'laterMessageNode') {
// Acknowledge message after the execution finished
await responsePromise.promise().then(async (data: IRun) => {
if (data.data.resultData.error) {
// The execution did fail
if (acknowledgeMode === 'executionFinishesSuccessfully') {
channel.nack(message);
messageTracker.answered(message);
return;
}
}
channel.ack(message);
messageTracker.answered(message);
});
} else if (responsePromiseHook && acknowledgeMode === 'laterMessageNode') {
await responsePromiseHook.promise().then(() => {
channel.ack(message);
messageTracker.answered(message);
});
} else {
// Acknowledge message directly
channel.ack(message);
}
} catch (error) {
const workflow = this.getWorkflow();
const node = this.getNode();
if (acknowledgeMode !== 'immediately') {
messageTracker.answered(message);
}
this.logger.error(
`There was a problem with the RabbitMQ Trigger node "${node.name}" in workflow "${workflow.id}": "${error.message}"`,
{
node: node.name,
workflowId: workflow.id,
},
);
}
}
});
const consumerTag = consumerInfo.consumerTag;
// The "closeFunction" function gets called by n8n whenever
// the workflow gets deactivated and can so clean up.
const closeFunction = async () => {
closeGotCalled = true;
try {
return await messageTracker.closeChannel(channel, consumerTag);
} catch (error) {
const workflow = this.getWorkflow();
const node = this.getNode();
this.logger.error(
`There was a problem closing the RabbitMQ Trigger node connection "${node.name}" in workflow "${workflow.id}": "${error.message}"`,
{
node: node.name,
workflowId: workflow.id,
},
);
}
};
return {
closeFunction,
};
}
}