Set up the Connection Manager
The connection manager handles all connection events and is the interface for transferring data between devices. It is a requirement for both advertisement and discovery.
First, A service ID should be chosen to uniquely identify your app. As a best
practice, use the package name of your app (for example, com.example.app
).
Next, choose a strategy
for your use case. The
strategy you select determines the connection topology for your app ( .cluster
, .star
.pointToPoint
).
Initialize the connection manager and implement its delegate methods:
Swift
import
NearbyConnections
class
Example
{
let
connectionManager
:
ConnectionManager
init
()
{
connectionManager
=
ConnectionManager
(
serviceID
:
"com.example.app"
,
strategy
:
.
cluster
)
connectionManager
.
delegate
=
self
}
}
extension
Example
:
ConnectionManagerDelegate
{
func
connectionManager
(
_
connectionManager
:
ConnectionManager
,
didReceive
verificationCode
:
String
,
from
endpointID
:
EndpointID
,
verificationHandler
:
@
escaping
(
Bool
)
-
>
Void
)
{
// Optionally show the user the verification code. Your app should call this handler
// with a value of `true` if the nearby endpoint should be trusted, or `false`
// otherwise.
verificationHandler
(
true
)
}
func
connectionManager
(
_
connectionManager
:
ConnectionManager
,
didReceive
data
:
Data
,
withID
payloadID
:
PayloadID
,
from
endpointID
:
EndpointID
)
{
// A simple byte payload has been received. This will always include the full data.
}
func
connectionManager
(
_
connectionManager
:
ConnectionManager
,
didReceive
stream
:
InputStream
,
withID
payloadID
:
PayloadID
,
from
endpointID
:
EndpointID
,
cancellationToken
token
:
CancellationToken
)
{
// We have received a readable stream.
}
func
connectionManager
(
_
connectionManager
:
ConnectionManager
,
didStartReceivingResourceWithID
payloadID
:
PayloadID
,
from
endpointID
:
EndpointID
,
at
localURL
:
URL
,
withName
name
:
String
,
cancellationToken
token
:
CancellationToken
)
{
// We have started receiving a file. We will receive a separate transfer update
// event when complete.
}
func
connectionManager
(
_
connectionManager
:
ConnectionManager
,
didReceiveTransferUpdate
update
:
TransferUpdate
,
from
endpointID
:
EndpointID
,
forPayload
payloadID
:
PayloadID
)
{
// A success, failure, cancelation or progress update.
}
func
connectionManager
(
_
connectionManager
:
ConnectionManager
,
didChangeTo
state
:
ConnectionState
,
for
endpointID
:
EndpointID
)
{
switch
state
{
case
.
connecting
:
// A connection to the remote endpoint is currently being established.
case
.
connected
:
// We're connected! Can now start sending and receiving data.
case
.
disconnected
:
// We've been disconnected from this endpoint. No more data can be sent or received.
case
.
rejected
:
// The connection was rejected by one or both sides.
}
}
}
Start Advertising
To start advertising, initialize the advertiser, implement its delegate methods,
and make a call to startAdvertising(using:)
.
Swift
import
NearbyConnections
class
Example
{
let
connectionManager
:
ConnectionManager
let
advertiser
:
Advertiser
init
()
{
connectionManager
=
ConnectionManager
(
serviceID
:
"com.example.app"
,
strategy
:
.
cluster
)
connectionManager
.
delegate
=
self
advertiser
=
Advertiser
(
connectionManager
:
connectionManager
)
advertiser
.
delegate
=
self
// The endpoint info can be used to provide arbitrary information to the
// discovering device (e.g. device name or type).
advertiser
.
startAdvertising
(
using
:
"My Device"
.
data
(
using
:
.
utf8
)
!
)
}
}
extension
Example
:
AdvertiserDelegate
{
func
advertiser
(
_
advertiser
:
Advertiser
,
didReceiveConnectionRequestFrom
endpointID
:
EndpointID
,
with
context
:
Data
,
connectionRequestHandler
:
@
escaping
(
Bool
)
-
>
Void
)
{
// Accept or reject any incoming connection requests. The connection will still need to
// be verified in the connection manager delegate.
connectionRequestHandler
(
true
)
}
}
Start Discovery
To start discovering, initialize the discoverer, implement its delegate methods,
and make a call to startDiscovery()
.
Swift
import
NearbyConnections
class
Example
{
let
connectionManager
:
ConnectionManager
let
discoverer
:
Discoverer
init
()
{
connectionManager
=
ConnectionManager
(
serviceID
:
"com.example.app"
,
strategy
:
.
cluster
)
connectionManager
.
delegate
=
self
discoverer
=
Discoverer
(
connectionManager
:
connectionManager
)
discoverer
.
delegate
=
self
discoverer
.
startDiscovery
()
}
}
extension
Example
:
DiscovererDelegate
{
func
discoverer
(
_
discoverer
:
Discoverer
,
didFind
endpointID
:
EndpointID
,
with
context
:
Data
)
{
// An endpoint was found.
}
func
discoverer
(
_
discoverer
:
Discoverer
,
didLose
endpointID
:
EndpointID
)
{
// A previously discovered endpoint has gone away.
}
}
