@architect/functions

Runtime helper library for serverless apps built with Architect

Check out the full docs: arc.codes

API

Given:

let arc = require('@architect/functions')

The following APIs exists:

arc.events.subscribe(fn)

Used to define a lambda function that will act as an event handler. Event handlers are defined in your application's Architect project manifest file under the @events pragma. The function code for the accompanying handler to each event should use arc.events.subscribe to wrap the handler. For example, given the following project manifest snippet:

@events
concerts

... the following file will be initialized representing the event handler for the concerts event, wherein you need to use arc.events.subscribe:

// file: src/events/concerts/index.js
let arc = require('@architect/functions')
module.exports = arc.events.subscribe(function(payload, callback) {
  console.log(payload)
  callback()
})

arc.events.publish(params, callback)

Publishes params.payload to the SNS Topic (event) with name params.name. The params.name parameter should match the event defined under @events. Building on the example we described above, to trigger the concerts event handler, we would set params.name to be concerts.

This allows you to publish events from any function within your application (@app .arc file namespace) to be handled by the event handler.

When running in local/testing mode, will publish the event to the sandbox.

arc.queues.subscribe(params, callback)

Used to define a lambda function that will act as a queue handler. Queue handlers are defined in your application's .arc file under the @queues pragma. The function code for the accompanying handler to each queued item should use arc.queues.subscribe to wrap the handler. For example, given the following .arc file snippet:

@queues
concert-tickets

... the following file will be initialized representing the event handler for the concert-tickets queue, wherein you need to use arc.queues.subscribe:

// file: src/queues/concert-tickets/index.js
let arc = require('@architect/functions')
module.exports = arc.queues.subscribe(function(payload, callback) {
  console.log(payload)
  callback()
})

arc.queues.publish(params, callback)

Publishes params.payload to the SQS Queue (queue) with name params.name. The params.name parameter should match the queue defined under @queues. Building on the example we described above, to trigger the concert-tickets queue handler, we would set params.name to be concert-tickets.

This allows you to publish to queues from any function within your application (@app .arc file namespace) to be handled by the queue handler.

When running in local/testing mode, will publish the event to the sandbox.

arc.static(assetPath, options)

Returns the fully-qualified URI of a static asset for the project-relative assetPath parameter. Takes into account:

• What environment (testing, staging, production) we are running in.
• Whether fingerprinting is enabled.
• Whether the override environment variable ARC_STATIC_BUCKET is present.

options is an object with the following currently-supported properties:

• stagePath: boolean, prepends /staging or /production to the asset path; useful if the current app is being run on an naked (non-domain-mapped) API Gateway

arc.tables(callback)

Returns an object that can be used to access data in database tables as defined under @tables in your .arc file. For example, given the following .arc file snippet:

@tables
accounts
  accountID *String

messages
  msgID *String

Running the following code:

let data = await arc.tables()

Would yield the following objects:

• data.accounts: reference to the accounts table
• data.messages: reference to the messages table

.. which contain the following methods:

• delete(key, callback): deletes the record from the table with key key and invokes callback with the result
• get(key, callback): retrieves the record from the table with key key and invokes callback when complete
• put(item, callback): adds item to the table and invokes callback with the item when complete
• query(params, callback): queries the table using params and invokes callback with the result
• scan(params, callback): scans the table using params and invokes callback with the result
• update(params, callback): updates an item in the table using params and invokes callback when complete

arc.ws.send({ id, payload })

Sends the object present on payload to the connection ID on id. Payload is passed to JSON.stringify() on your behalf. Uses postToConnection from the ApiGatewayManagementApi. Returns a promise with no data on success.