'Hello World' Sync

Once you've set up your environment, try on Ditto and perform your first peer-to-peer sync.

Intended to get you oriented, this article provides a streamlined process for integrating sync functionality within your app.

If you prefer building and exploring through a chat app, and so on, see Example Projects Overview.

Integrating Sync Functionality

Integrate the Ditto SDK in your codebase, set up authentication, and then start syncing offline:

From the top-most scope of your app's codebase, add the following to set up authentication and start syncing offline.

DittoLogger.minimumLogLevel = .debug
let ditto = Ditto(identity: .onlinePlayground(
    appID: "REPLACE_ME_WITH_YOUR_APP_ID",
    token: "REPLACE_ME_WITH_YOUR_PLAYGROUND_TOKEN"
))
do {
  try ditto.startSync()
} catch (let err) {
  print(err.localizedDescription)
}

Replace YOUR_APP_ID and YOUR_PLAYGROUND_TOKEN with your access credentials available from the portal.

Creating Subscriptions

To register a new sync subscription in your app. For example, the following snippet demonstrates how to establish a subscription to sync updates to documents in the cars collection with a field of color set to the value blue:

ditto.sync.registerSubscription("SELECT * FROM cars")

Sync subscriptions also support argument injection using the :argument syntax in DQL:

ditto.sync.registerSubscription(
  "SELECT * FROM cars WHERE color = :color",
  Collections.singletonMap("color", "blue"))

Retrieving Subscriptions

Retrieve active sync subscriptions by calling the subscriptions method on the ditto.sync namespace:

const activeSubscriptions = ditto.sync.subscriptions

Canceling Subscriptions

To cancel a subscription, call cancel on the subscription object you set up to establish your subscription:

subscription.close()

You can check if a sync subscription is canceled by using the isCancelled field on the subscription object:

subscription.isCancelled