Class Subscription (4.0.7)

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

pubsub.getSubscriptions((err, subscriptions) => {
  // `subscriptions` is an array of Subscription objects.
});

const topic = pubsub.topic('my-topic');
topic.getSubscriptions((err, subscriptions) => {
  // `subscriptions` is an array of Subscription objects.
});

const topic = pubsub.topic('my-topic');
topic.createSubscription('new-subscription', (err, subscription) => {
  // `subscription` is a Subscription object.
});

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');
// `subscription` is a Subscription object.

// Register an error handler.
subscription.on('error', (err) => {});

// Register a debug handler, to catch non-fatal errors and other messages.
subscription.on('debug', msg => { console.log(msg.message); });

// Register a close handler in case the subscriber closes unexpectedly
subscription.on('close', () => {});

// Register a listener for `message` events.
function onMessage(message) {
  // Called every time a message is received.

  // message.id = ID of the message.
  // message.ackId = ID used to acknowledge the message receival.
  // message.data = Contents of the message.
  // message.attributes = Attributes of the message.
  // message.publishTime = Date when Pub/Sub received the message.

  // Ack the message:
  // message.ack();

  // This doesn't ack the message, but allows more messages to be retrieved
  // if your limit was hit or if you don't want to ack the message.
  // message.nack();
}
subscription.on('message', onMessage);

// Remove the listener from receiving `message` events.
subscription.removeListener('message', onMessage);

const subscription = topic.subscription('my-sub', {
  flowControl: {
    maxMessages: 1,
    // this tells the client to manage and lock any excess messages
    allowExcessMessages: false
  }
});

subscription.close(err => {
  if (err) {
    // Error handling omitted.
  }
});

// If the callback is omitted a Promise will be returned.
subscription.close().then(() => {});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('newMessages');
const callback = function(err, subscription, apiResponse) {};

subscription.create(callback);

subscription.create({
  ackDeadlineSeconds: 90
}, callback);

const [sub, apiResponse] = await subscription.create();

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

const callback = (err, snapshot, apiResponse) => {
  if (!err) {
    // The snapshot was created successfully.
  }
};

subscription.createSnapshot('my-snapshot', callback);

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.createSnapshot('my-snapshot').then((data) => {
  const snapshot = data[0];
  const apiResponse = data[1];
});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

subscription.delete((err, apiResponse) => {});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.delete().then((data) => {
  const apiResponse = data[0];
});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

subscription.detached((err, exists) => {});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.detached().then((data) => {
  const detached = data[0];
});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

subscription.exists((err, exists) => {});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.exists().then((data) => {
  const exists = data[0];
});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

subscription.get((err, subscription, apiResponse) => {
  // The `subscription` data has been populated.
});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.get().then((data) => {
  const subscription = data[0];
  const apiResponse = data[1];
});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

subscription.getMetadata((err, apiResponse) => {
  if (err) {
    // Error handling omitted.
  }
});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.getMetadata().then((data) => {
  const apiResponse = data[0];
});

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();

const topic = pubsub.topic('my-topic');
const subscription = topic.subscription('my-subscription');

const pushConfig = {
  pushEndpoint: 'https://mydomain.com/push',
  attributes: {
    key: 'value'
  },
  oidcToken: {
    serviceAccountEmail: 'myproject@appspot.gserviceaccount.com',
    audience: 'myaudience'
  }
};

subscription.modifyPushConfig(pushConfig, (err, apiResponse) => {
  if (err) {
    // Error handling omitted.
  }
});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.modifyPushConfig(pushConfig).then((data) => {
  const apiResponse = data[0];
});

subscription.on('message', message => message.ack());

// Close the subscription.
subscription.close(err => {
  if (err) {
    // Error handling omitted.
  }

  The subscription has been closed and messages will no longer be received.
});

// Resume receiving messages.
subscription.open();

const callback = (err, resp) => {
  if (!err) {
    // Seek was successful.
  }
};

subscription.seek('my-snapshot', callback);

//-
// Alternatively, to specify a certain point in time, you can provide a
Date
// object.
//-
const date = new Date('October 21 2015');

subscription.seek(date, callback);

const metadata = {
  key: 'value'
};

subscription.setMetadata(metadata, (err, apiResponse) => {
  if (err) {
    // Error handling omitted.
  }
});

//-
// If the callback is omitted, we'll return a Promise.
//-
subscription.setMetadata(metadata).then((data) => {
  const apiResponse = data[0];
});

const snapshot = subscription.snapshot('my-snapshot');