Using iii
Using Triggers
Trigger Components
A trigger consists of three parts:
- Trigger Type: The mechanism that initiates execution (api, event, cron, log)
- Configuration: Type-specific settings (path, schedule, topics)
- Function Path: The function to invoke when triggered
bridge.registerTrigger({
trigger_type: 'api', // 1. Trigger Type
config: {
// 2. Configuration
api_path: '/users',
http_method: 'POST',
},
function_path: 'users.create', // 3. Function Path
})Registering Triggers
Triggers are registered by workers after establishing a connection to the engine:
Registration Flow
Step 1: Register Function
First, register the function that will be invoked:
bridge.registerFunction({
function_path: 'users.create',
handler: async (data) => {
// Function logic
return { id: '123', ...data }
},
})Step 2: Register Trigger
Then, register a trigger that routes to that function:
bridge.registerTrigger({
trigger_type: 'api',
function_path: 'users.create', // Must match registered function
config: {
api_path: '/users',
http_method: 'POST',
},
})Step 3: Trigger Active
The engine sets up the trigger in the appropriate module. Now when an HTTP POST request comes to /users, the users.create function will be invoked.
Trigger Configurations by Type
API Trigger Configuration
{
trigger_type: 'api',
function_path: 'api.endpoint',
config: {
api_path: '/api/v1/resource/:id', // Supports path parameters
http_method: 'GET' | 'POST' | 'PUT' | 'DELETE' | 'PATCH'
}
}Path Parameters: Extract values from URL
// Trigger: api_path: '/users/:userId/posts/:postId'
// Request: GET /users/123/posts/456
// Handler receives: { path_params: { userId: '123', postId: '456' } }Event Trigger Configuration
{
trigger_type: 'event',
function_path: 'events.handler',
config: {
subscribes: [
'user.created',
'user.updated',
'user.deleted'
]
}
}Multiple Subscriptions: One trigger can subscribe to multiple topics.
Cron Trigger Configuration
{
trigger_type: 'cron',
function_path: 'jobs.scheduled',
config: {
cron: '*/5 * * * *' // Every 5 minutes
}
}Cron Expression: Standard 5-field format (minute hour day month weekday)
Log Trigger Configuration
{
trigger_type: 'log',
function_path: 'monitoring.onError',
config: {
level: 'error' // Optional: filter by log level
}
}Log Levels: info, warn, error, debug (omit to receive all levels)
Stream Trigger Configuration
{
trigger_type: 'streams:join',
function_path: 'streams.onJoin',
config: {} // No configuration needed
}Multiple Triggers to One Function
A single function can have multiple triggers:
// Register function once
bridge.registerFunction({
function_path: 'users.notify',
handler: async (data) => {
await sendNotification(data)
},
})
// Trigger from API
bridge.registerTrigger({
trigger_type: 'api',
function_path: 'users.notify',
config: { api_path: '/notify', http_method: 'POST' },
})
// Trigger from events
bridge.registerTrigger({
trigger_type: 'event',
function_path: 'users.notify',
config: { subscribes: ['user.created', 'order.placed'] },
})
// Trigger from cron
bridge.registerTrigger({
trigger_type: 'cron',
function_path: 'users.notify',
config: { cron: '0 9 * * *' },
})Use Case: Send notifications via API calls, events, or scheduled jobs using the same logic.
Trigger Lifecycle
Unregistering Triggers
Remove triggers dynamically:
const triggerId = 'unique-trigger-id'
bridge.registerTrigger({
id: triggerId,
trigger_type: 'api',
function_path: 'api.temp',
config: { api_path: '/temp', http_method: 'GET' },
})
// Later...
bridge.unregisterTrigger(triggerId)Trigger Patterns
Webhook Handler
bridge.registerFunction({
function_path: 'webhooks.github',
handler: async (req) => {
const event = req.headers['x-github-event']
const payload = req.body
await processGitHubWebhook(event, payload)
return { status: 200, body: { received: true } }
},
})
bridge.registerTrigger({
trigger_type: 'api',
function_path: 'webhooks.github',
config: {
api_path: '/webhooks/github',
http_method: 'POST',
},
})Event Chain
// Step 1: Order placed
bridge.registerFunction({
function_path: 'orders.process',
handler: async (order) => {
await saveOrder(order)
// Emit next event in chain
await bridge.invokeFunction({
function_path: 'event.emit',
data: {
topic: 'order.processed',
data: order,
},
})
},
})
bridge.registerTrigger({
trigger_type: 'event',
function_path: 'orders.process',
config: { subscribes: ['order.placed'] },
})
// Step 2: Send confirmation
bridge.registerFunction({
function_path: 'orders.sendConfirmation',
handler: async (order) => {
await sendEmail(order.email, 'Order confirmed')
},
})
bridge.registerTrigger({
trigger_type: 'event',
function_path: 'orders.sendConfirmation',
config: { subscribes: ['order.processed'] },
})Scheduled Cleanup
bridge.registerFunction({
function_path: 'maintenance.cleanup',
handler: async () => {
const deleted = await deleteOldRecords()
logger.info(`Deleted ${deleted} old records`)
},
})
bridge.registerTrigger({
trigger_type: 'cron',
function_path: 'maintenance.cleanup',
config: {
cron: '0 3 * * *', // Every day at 3 AM
},
})