Initializer

init(serviceType:discoveryInfo:session:)

Initializes an advertiser assistant object.

Declaration

init(serviceType: String, discoveryInfo info: [String : String]?, session: MCSession)

Parameters

serviceType

The type of service to advertise. This should be a short text string that describes the app's networking protocol, in the same format as a Bonjour service type (without the transport protocol) and meeting the restrictions of RFC 6335 (section 5.1) governing Service Name Syntax. In particular, the string:

  • Must be 1–15 characters long

  • Can contain only ASCII lowercase letters, numbers, and hyphens

  • Must contain at least one ASCII letter

  • Must not begin or end with a hyphen

  • Must not contain hyphens adjacent to other hyphens.

This name should be easily distinguished from unrelated services. For example, a text chat app made by ABC company could use the service type abc-txtchat.

For more details, read Domain Naming Conventions.

info

A dictionary of key-value pairs that are made available to browsers. Each key and value must be an NSString object.

This data is advertised using a Bonjour TXT record, encoded according to RFC 6763 (section 6). As a result:

  • The key-value pair must be no longer than 255 bytes (total) when encoded in UTF-8 format with an equals sign (=) between the key and the value.

  • Keys cannot contain an equals sign.

For optimal performance, the total size of the keys and values in this dictionary should be no more than about 400 bytes so that the entire advertisement can fit within a single Bluetooth data packet. For details on the maximum allowable length, read Monitoring a Bonjour Service.

If the data you need to provide is too large to fit within these constraints, create a custom discovery class using Bonjour for discovery and your choice of networking protocols for exchanging the information.

session

The session into which new peers should be added after they accept the invitation.

Return Value

An initialized instance, or nil if an error occurred.

Discussion

This method throws an exception if a valid peerID object is not provided, or if serviceType is not a legal Bonjour service type.

See Also

Initializing and Configuring

var session: MCSession

The session into which new peers are added after accepting an invitation.

var delegate: MCAdvertiserAssistantDelegate?

The delegate object that handles advertising-assistant-related events.

var discoveryInfo: [String : String]?

The info dictionary that was passed when this object was initialized.

var serviceType: String

The service type that your app is advertising.