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Usage

object:Channel

channel object exposes trust-safe flexible Pub/Sub messaging properties, functions and events to build real-time event messaging / event driven applications at scale.

Concepts

  • A message is attached to an event
  • Group similar events into a channel
  • Subscribe to a channel to receive all channel event messages.
  • Publish event message to the channel and it will be sent to all the channel subscribers who are connected to dataBrdiges network and online.
  • if you need to have an access controlled channel, prefix the channel name with pvt: , prs: and sys: .
  • Note dataBrdiges have 2 septate libraries (client lib, server lib). You are reading the server library api document.
    • Server lib uses app.key along with secret to get access to all channels including pvt: , prs: and sys: channels linked to the application.
    • Whereas application using client library (client application) will always need to pass a trust-token to access restricted channels (pvt: prs: sys: ) . A trust-token is a JWT document created using a combination of channelname + sessionid + app.secret. Trust token can be created by application having access to app.key's secret.
    • you can use your existing access control, authorization and session identification rule-set, process and methods to create a trust-token instructing the dataBrdiges router to accept the pvt: prs: and sys: channel subscription, connection of from client application.
    • Trust-tokens allows you to enable secured, access controlled and compliance driven real-time event driven messaging in your existing and new initiative applications.

dataBrdiges library supports 4 types of channel. The namespace is the 4 characters preceding the channelName (pvt:,prs:,sys:), identifying which type of channel the application is connecting to.

Channel Type Channel Name Style Description
Public channelName Public channel is used to send and receive messages that are to be publicly available. This channel type does not require any trust authorization token to subscribe.
e.g channelName = mychannel
Private **pvt:**channeName Private channels is restricted channel. e.g channelName = pvt:mychannel
Presence **prs:**channeName Presence channels is a specialized private channel with additional feature of presence awareness. Subscribing to presence channel allows application to be notified of members joining / leaving the channel. e.g channelName = prs:mychannel
System **sys:**channeName System channel is a specialized Presence channel to build command and control applications. Using System channel to create command and control server applications to send messages to devices and application using dataBrdiges library in **trust-safe manner **, build smart update configuration system and implement **trust-safe ** actions for remote and automated management. System channel allows application to send and receive messages with the server application (using dataBrdiges server library).
e.g channelName = sys:systeminfo

Subscribe to Channel

Application that subscribes to a channel will receive messages and can send messages.

subscribe()

The default method for subscribing to a channel involves invoking the channel.subscribe function of your dataBrdiges object:

try {
    const subscribed_channel = dbridge.channel.subscribe('mychannel');
} catch (err) {
    console.log(err.source, err.code, err.message);
}

try:
    subscribed_channel =  await dbridge.channel.subscribe('mychannel')
except dBError as e:
    print(e.code, e.source, e.message)

using dBridges.channel;
try {
    channel subscribed_channel = dbridge.channel.subscribe('mychannel');
} catch (dBError err) {
     Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
Parameter Rules Description
string channelName OR
pvt:channelName OR
prs:channelName OR
sys:channelNameOR
sys:*		 channelName to which subscription to be done.
Return Type Description
object channel object which events and related functions can be bound to.

Application can directly work with dataBrdiges object without using Channel object. 

try {
    dbridge.channel.subscribe('mychannel');
} catch (err) {
    console.log(err.source, err.code, err.message);
}

try:
    await dbridge.channel.subscribe('mychannel')
except dBError as e:
    print(e.code, e.source, e.message)

try {
    dbridge.channel.subscribe('mychannel');
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
Exceptions:
Source Code Description
DBLIB_CHANNEL_SUBSCRIBE NETWORK_DISCONNECTED Connection to dataBrdiges network is not active.
DBLIB_CHANNEL_SUBSCRIBE INVALID_CHANNELNAME Applicable for below conditions
1. channelName is not defined.
2. channelName validation error, typeof() channelName is not type string
3. channelName validation error, channelName fails a-zA-Z0-9\.:_- validation.
DBLIB_CHANNEL_SUBSCRIBE INVALID_CHANNELNAME_LENGTH channelName validation error, length of channelName greater than 64
DBLIB_CHANNEL_SUBSCRIBE CHANNEL_ALREADY_SUBSCRIBED channelName is already subscribed.

unsubscribe()

To unsubscribe from a subscribed channel, invoke the unsubscribe function of your dataBrdiges object. unsubscribe cannot be done on channel object.

try {
    dbridge.channel.unsubscribe('mychannel');
} catch (err) {
    console.log(err.source, err.code, err.message);
}

try:
    dbridge.channel.unsubscribe('mychannel')
except dBError as e:
    print(e.code, e.source, e.message)

try {
    dbridge.channel.subscribe('mychannel');
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
Parameter Rules Description
string channelName **OR*
pvt:**channelName **OR
prs:**channelName **OR
**sys:**channelName*		 *channel*Name to which un-subscription to be done.
Return Type Description
NA
Exceptions:
Source Code Description
DBLIB_CHANNEL_UNSUBSCRIBE NETWORK_DISCONNECTED Connection to dataBrdiges network is not active.
DBLIB_CHANNEL_UNSUBSCRIBE CHANNEL_NOT_SUBSCRIBED channelName is not subscribed.
DBLIB_CHANNEL_UNSUBSCRIBE UNSUBSCRIBE_ALREADY_INITIATED unsubscription to the channel is already initiated and hence the current unsubscribe command exited with exception.

Channel Information

isOnline()

dBridgeObject as well as channelObject provides a function to check if the channel is online. The best practice is to check the channel is online before publishing any message.

const isonline = dbridge.channel.isOnline('mychannel');
// Using channelObject
const isonline = subscribed_channel.isOnline(); 

isonline = dbridge.channel.isOnline('mychannel')
// Using channelObject
isonline = subscribed_channel.isOnline()

bool isonline = dbridge.channel.isOnline('mychannel');
// Using channelObject
bool isonline = subscribed_channel.isOnline();
Parameter Rules Description
string channelName **OR*
pvt:**channelName **OR
prs:**channelName **OR
**sys:**channelName*		 *channel*Name
Return Values Description
boolean Is the current status of channel online or offline.

list()

dBridgeObject provides a function to get list of successfully subscribed or connected channel. 

const channels = dbridge.channel.list();
#=> [{"name":  "mychannel" , "type": "subscribed/connect" ,  "isonline": true/false }];

channels = dbridge.channel.list()
#=> [{"name":  "mychannel" , "type": "subscribed/connect" ,  "isonline": True/False }]

List<Dictionary<string, object>> channels = dbridge.channel.list();
#=> [{"name":  "mychannel" , "type": "subscribed/connect" ,  "isonline": true/false }];
Return Type Description
array of dict Array of channels subscribed or connected.

Dictionary contains below information.

Key Description
name (string) channelName of subscribed or connected channel.
type (string) subscribed
isonline (boolean) Is the current status of channel online or offline.

getChannelName()

channelObject provides a function to get the channelName.

Return Type Description
string channelName of subscribed channel.

Publish to Channel

Publish event-message using the publish function on an instance of the channel object.

A message is linked to an event and hence event-message. dataBrdiges allows you to bind to various events to create rich event processing flows.

publish()

The default method for publishing user-defined events to a channel involves invoking the channel.publish function of your channelObject for which it has connected to OR using dbridgeObject giving the channelName as parameter.

Note: channel.publish is not allowed using channelObject subscribed to sys:* channel.

// Using dbridgeObject 
try {
    dbridge.channel.publish(channelName, event, payload, excludeSessionId, sourceId, seqno);
} catch (err) {
    console.log(err.source, err.code, err.message);
}
// Using channelObject 
try {
    channelObject.publish(event, payload, excludeSessionId, sourceId, seqno);
} catch (err) {
    console.log(err.source, err.code, err.message);
}
// Best practice is to check the channel is online before publishing any message.
if (channelObject.isOnline()) {
    try {
        channelObject.publish(event, payload, excludeSessionId, sourceId, seqno);
    } catch (err) {
        console.log(err.source, err.code, err.message);
    }
}

# Using dbridgeObject 
try:
    dbridge.channe.publish(channelName, event, payload, excludeSessionId, sourceId, seqno)
except dBError as e:
  print(e.code, e.source, e.message) 

# Using channelObject 
try:
    channelObject.publish(eventname, payload, excludeSessionId, sourceId, seqno)
except dBError as e:
  print(e.code, e.source, e.message)

#// Best practice is to check the channel is online before publishing any message.
if channelObject.isOnline():
    try:
        channelObject.publish(eventname, payload, excludeSessionId, sourceId, seqno)
    except dBError as e:
      print(e.code, e.source, e.message)

// Using dbridgeObject 
try {
    dbridge.channel.publish(channelName, event, payload, excludeSessionId, sourceId, seqno);
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

// Using channelObject 
try {
    channelObject.publish(event, payload, excludeSessionId, sourceId, seqno);
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

// Best practice is to check the channel is online before publishing any message.
if (channelObject.isOnline()) {
    try {
        channelObject.publish(event, payload, excludeSessionId, sourceId, seqno);
    } catch (dBError err) {
        Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
    }    
}
Parameter Description
channelName (string) Channel name for which details are required.
event (string) event Name to which the message to be sent. event Name cannot start with dbridges:
payload (string) Payload to be sent with the event.
excludeSessionId (string) Excludes the event from being sent to a specific sessionid (connection).

For example when a server application (example: chat server) sends event message on behalf of a specific session ( example: chat user) to a channel (example: chat group), the sessionID (example: chat user) will be excluded to receive its own message.
sourceId (string) Required in case of presence(prs:) and system (sys:) channel. When sending a message to a presence(prs:) or system (sys:) channel, application need to specify a message source by using this sourceId.

For example when a server application (example: chat server) sends event message on behalf of a specific session ( example: chat user) to a channel (example: chat group), the sourceID (example: chat user information) can be attached using sourceID to the event message. This allows all message recipient to know who has sent the message.
seqno (string) [optional] Message sequence number. This is optional parameter. seqno can be used by applications to manage message queue processing by the subscribers.
Return Values Description
NA
Exceptions:
Source Code Description
DBLIB_CHANNEL_PUBLISH NETWORK_DISCONNECTED Connection to dataBrdiges network is not active.
DBLIB_CHANNEL_PUBLISH INVALID_CHANNELNAME Applicable for below conditions
1. channelName validation error, typeof() channelName is not type string
2. channelName validation error, channelName fails a-zA-Z0-9\.:_- validation.
3. channelName is sys:*
4. channelName is not defined.
DBLIB_CHANNEL_PUBLISH INVALID_CHANNELNAME_LENGTH channelName validation error, length of channelName greater than 64
DBLIB_CHANNEL_PUBLISH INVALID_SUBJECT Applicable for below conditions
1. event validation error, event is not defined
2. event validation error, typeof() event is not type string

Send Message to Members / sessionID

It's possible to send message to individual sessionId using the channel.sendmsg function on an instance of the channelObject or using dbridgeObject.

sendmsg()

The default method for send message user-defined events to a individual sessionId involves invoking the channel.sendmsg function of your channelObject for which it has connected to OR using dbridgeObject giving the channelName as parameter.

Note: channel.sendmsg is not allowed using channelObject subscribed to sys:* channel.

// Using dbridgeObject 
try {
    dbridge.channel.sendmsg(channelName, event, payload, toSessionId, sourceId, seqno);
} catch (err) {
    console.log(err.source, err.code, err.message);
}
// Using channelObject 
try {
    channelObject.sendmsg(event, payload, toSessionId, sourceId, seqno);
} catch (err) {
    console.log(err.source, err.code, err.message);
}

// Best practice is to check the channel is online before publishing any message.
if (channelObject.isOnline()) {
    try {
        channelObject.sendmsg(event, payload, toSessionId, sourceId, seqno);
    } catch (err) {
        console.log(err.source, err.code, err.message);
    }
}

# Using dbridgeObject 
try:
    dbridge.channel.sendmsg(channelName, event, payload, toSessionId, sourceId, seqno)
except dBError as e:
    print(e.code, e.source, e.message) 

# Using channelObject 
try:
    channelObject.sendmsg( event, payload, toSessionId, sourceId, seqno)
except dBError as e:
    print(e.code, e.source, e.message) 

# Best practice is to check the channel is online before publishing any message.
if channelObject.isOnline():
    try:
        channelObject.sendmsg(event, payload, toSessionId, sourceId, seqno);
    except dBError as e:
    print(e.code, e.source, e.message) 

// Using dbridgeObject 
try {
    dbridge.channel.sendmsg(channelName, event, payload, toSessionId, sourceId, seqno);
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

// Using channelObject 
try {
    channelObject.sendmsg(event, payload, toSessionId, sourceId, seqno);
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

// Best practice is to check the channel is online before publishing any message.
if {channelObject.isOnline()){
    try {
        dbridge.channel.sendmsg(channelName, event, payload, toSessionId, sourceId, seqno);
    } catch (dBError err) {
        Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
    }        
}
Parameter Description
channelName (string) Channel name for which details are required.
event (string) event Name to which the message to be sent. event Name cannot start with dbridges:
payload (string) Payload to be sent with the event.
toSessionId (string) sessionid where the message to be sent.
sourceId (string) Required in case of presence(prs:) and system (sys:) channel. When sending a message to a presence(prs:) or system (sys:) channel, application need to specify a message source by using this sourceId.

For example when a server application (example: chat server) sends event message on behalf of a specific session ( example: chat user) to a channel (example: chat group), the sourceID (example: chat user information) can be attached using sourceID to the event message. This allows all message recipient to know who has sent the message.
seqno (string) [optional] Message sequence number. This is optional parameter. seqno can be used by applications to manage message queue processing by the subscribers.
Return Values Description
NA
Exceptions:
Source Code Description
DBLIB_CHANNEL_SENDMSG NETWORK_DISCONNECTED Connection to dataBrdiges network is not active.
DBLIB_CHANNEL_SENDMSG INVALID_CHANNELNAME Applicable for below conditions
1. channelName validation error, typeof() channelName is not type string
2. channelName validation error, channelName fails a-zA-Z0-9\.:_- validation.
3. channelName is sys:*
4. channelName is not defined.
5. channelType is prs: and sourceId is not provided.
6. channelName contains : and first token is not pvt,prs,sys
DBLIB_CHANNEL_SENDMSG INVALID_CHANNELNAME_LENGTH channelName validation error, length of channelName greater than 64

Binding to events

A message is linked to an event and hence event-message. dataBrdiges allows you to bind to various events to create rich event processing flows. An application needs to bind to event to process the received message.

You can use the following methods either on a channelObject, to bind to events on a particular channel; or on the dbridgeObject, to bind to events on all subscribed channels simultaneously.

bind and unbind

Bind to "event" on channel: payload and metadata is received.

//  Binding to channel events on channelObject using Anonymous function.
try {
    channelObject.bind('eventName',  (payload, metadata) => {
        console.log(payload, metadata);
    });
} catch(err){
     console.log(err.source, err.code, err.message);
}

// Binding to channel events on dbridgeObject using Anonymous function.
try {
    dbridge.channel.bind('eventName', (payload, metadata) => {
        console.log(payload, metadata);
    });
} catch(err){
     console.log(err.source, err.code, err.message);
}

// Binding to channel events on channelObject using user function.
const myEventHandler = (payload, metadata) =>{
    console.log(payload, metadata);
};

try {
    dbridge.channel.bind('eventName', myEventHandler);
} catch(err){
     console.log(err.source, err.code, err.message);
}

# Binding to channel events on channelObject  
def eventFunction(payload ,  metadata):
    print(payload , metadata)

try:
    channelObject.bind('eventName',  eventFunction)
except dBError as e:
    print(e.code, e.source, e.message) 

# Binding to channel events on dbridgeObject 
try {
    dbridge.channel.bind('eventName', eventFunction)
except dBError as e:
    print(e.code, e.source, e.message) 

//  Binding to channel events on channelObject using Anonymous function.
Action<object,object> iChannelStatus;
try {
    channelObject.bind('eventName',  iChannelStatus = (object payload, object metadata) => {
        Console.WriteLine("{0} , {1} " , payload, metadata);
    });
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

// Binding to channel events on dbridgeObject using Anonymous function.
try {
    dbridge.channel.bind('eventName', iChannelStatus = (object payload, object metadata) => {
        Console.WriteLine("{0} , {1} " , payload, metadata);
    });
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

// Binding to channel events on channelObject using user function.
public void channelStatus(object payload, object metadata){
    Console.WriteLine("{0} , {1} " , payload, metadata);
}

Action<object,object> iChannelStatus = channelStatus;

try {
    dbridge.channel.bind('eventName', iChannelStatus);
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
Parameter Description
event (string) event Name to which binding to be done.
Callback parameters
payload:

(string) Payload data sent by the publisher.

metadata (dict):
{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "event",               // (string) eventName 
    "sourcesysid": "",                  // (string) Sender system identity, applicable only for presence or system channel.
    "sqnum": "1",                       // (string) user defined, sent during publish function.
    "sessionid": "",                    // (string) Sender sessionid, applicable only for presence or system channel.
    "intime": 1645554960732             // (string) EPOC time of the sender at time of publish.
}
Exceptions:
Source Code Description
DBLIB_CONNECT_BIND INVALID_EVENTNAME Invalid Event name. Not in user-defined events or default events.
DBLIB_CONNECT_BIND INVALID_CALLBACK If "callback function" is not declared or typeof() variable defined is not a "function".

Unbind behavior varies depending on which parameters you provide it with. For example:

// Remove just `handler` of the `event` in the subscribed/connected channel 
channelObject.unbind('event',handler);

// Remove all `handler` of the `event` in the subscribed/connected channel
channelObject.unbind('event');

//Remove all handlers for the all event in the subscribed/connected channel
channelObject.unbind();

// Remove `handler` of the `event` for all events across all subscribed/connected channels
dbridge.channel.unbind('event',handler);

// Remove all handlers of the `event` for all events across all subscribed/connected channels
dbridge.channel.unbind('event');

// Remove all handlers for all events across all subscribed/connected channels
dbridge.channel.unbind();

# Remove just `handler` of the `event` in the subscribed/connected channel 
channelObject.unbind('event',handler)

# Remove all `handler` of the `event` in the subscribed/connected channel
channelObject.unbind('event')

# Remove all handlers for the all event in the subscribed/connected channel
channelObject.unbind()

# Remove `handler` of the `event` for all events across all subscribed/connected channels
dbridge.channel.unbind('event',handler)

# Remove all handlers of the `event` for all events across all subscribed/connected channels
dbridge.channel.unbind('event')

# Remove all handlers for all events across all subscribed/connected channels
dbridge.channel.unbind()

// Remove just `handler` of the `event` in the subscribed/connected channel 
channelObject.unbind('event',handler);

// Remove all `handler` of the `event` in the subscribed/connected channel
channelObject.unbind('event');

//Remove all handlers for the all event in the subscribed/connected channel
channelObject.unbind();

// Remove `handler` of the `event` for all events across all subscribed/connected channels
dbridge.channel.unbind('event',handler);

// Remove all handlers of the `event` for all events across all subscribed/connected channels
dbridge.channel.unbind('event');

// Remove all handlers for all events across all subscribed/connected channels
dbridge.channel.unbind();

bind_all and unbind_all

bind_all and unbind_all work much like bind and unbind, but instead of only firing callbacks on a specific event, they fire callbacks on any event, and provide that event in the metadata to the handler along with the payload. 

//  Binding to all channel events on channelObject  
try {
    channelObject.bind_all((payload, metadata) => {
        console.log(payload, metadata);
    });
} catch(err){
     console.log(err.source, err.code, err.message);
}

// Binding to all channel events on dbridgeObject 

try {
    dbridge.channel.bind_all((payload, metadata) => {
        console.log(payload, metadata);
    });
} catch(err){
     console.log(err.source, err.code, err.message);
}

# Binding to channel events on channelObject  
def eventFunction(payload ,  metadata):
    print(payload , metadata)

try:
    channelObject.bind_all('event',  eventFunction)
except dBError as e:
    print(e.code, e.source, e.message) 

# Binding to channel events on dbridgeObject 

try {
    dbridge.channel.bind_all('event', eventFunction)
except dBError as e:
    print(e.code, e.source, e.message)

//  Binding to all channel events on channelObject  
try {
    Action<object , object> ichannelstatus;
    channelObject.bind_all(ichannelstatus =  (payload, metadata) => {
        Console.WriteLine("{0} , {1} " , payload, metadata);
    });
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
// Binding to all channel events on dbridgeObject 

try {
    Action<object , object> ichannelstatus;
    dbridge.channel.bind_all(ichannelstatus =  (payload, metadata) => {
        Console.WriteLine("{0} , {1} " , payload, metadata);
    });
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}

Callback out parameter payload, metadata details are explained with each event below in this document.

Exceptions:
Source Code Description
DBLIB_CONNECT_BIND INVALID_CALLBACK If "callback function" is not declared or typeof() variable defined is not a "function".

unbind_all works similarly to unbind.

// Remove just `handler` across the channel 
channelObject.unbind_all(handler);

//Remove all handlers for the all event in the subscribed/connected channel
channelObject.unbind_all();

// Remove `handler` across the subscribed/connected channels
dbridge.channel.unbind_all(handler);

// Remove all handlers for all events across all subscribed/connected channels
dbridge.channel.unbind_all();

# Remove just `handler` across the channel 
channelObject.unbind_all(handler)

#Remove all handlers for the all event in the subscribed/connected channel
channelObject.unbind_all()

# Remove `handler` across the subscribed/connected channels
dbridge.channel.unbind_all(handler)

# Remove all handlers for all events across all subscribed/connected channels
dbridge.channel.unbind_all()

// Remove just `handler` across the channel 
channelObject.unbind_all(handler);

//Remove all handlers for the all event in the subscribed/connected channel
channelObject.unbind_all();

// Remove `handler` across the subscribed/connected channels
dbridge.channel.unbind_all(handler);

// Remove all handlers for all events across all subscribed/connected channels
dbridge.channel.unbind_all();

System events for channel object

There are a number of events which are triggered internally by the library, but can also be of use elsewhere. Below are the list of all events triggered by the library.

Below syntax is same for all system events.

//  Binding to systemevent on channelObject  
try {
    channelObject.bind('dbridges:subscribe.success', (payload, metadata) => {
        console.log( payload, metadata);
    });
} catch(err) {
     console.log(err.source, err.code, err.message);
}
//  Binding to systemevent on dbridgeObject  
try {
    dbridge.channel.bind('dbridges:subscribe.success', (payload, metadata) => {
        console.log( payload, metadata);
    });
} catch(err) {
     console.log(err.source, err.code, err.message);
}

# Binding to systemevent on channelObject  
def eventFunction(payload ,  metadata):
    print(payload , metadata)

try:
    channelObject.bind_all('dbridges:subscribe.success',  eventFunction)
except dBError as e:
    print(e.code, e.source, e.message) 

# Binding to systemevent on dbridgeObject 

try:
    dbridge.channel.bind_all('dbridges:subscribe.success', eventFunction)
except dBError as e:
    print(e.code, e.source, e.message)

//  Binding to systemevent on channelObject  
try {
    Action<object,object> isubscribeevent;
    channelObject.bind('dbridges:subscribe.success', isubscribeevent = (payload, metadata) => {
        Console.WriteLine("{0} , {1} " , payload, metadata);
    });
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
//  Binding to systemevent on dbridgeObject  
try {
    Action<object,object> isubscribeevent;
    dbridge.channel.bind('dbridges:subscribe.success', isubscribeevent = (payload, metadata) => {
        Console.WriteLine("{0} , {1} " , payload, metadata);
    });
} catch (dBError err) {
    Console.WriteLine("{0} ,  {1} , {2}" , err.source, err.code, err.message);
}
dbridges:subscribe.success
Callback parameters

payload:

null

metadata (dict):

{
    "channelname": "channelName" ,          // (string) channelName to which subscription is done.
    "eventname": "dbridges:subscribe.success",// (string) eventName 
    "sourcesysid": "",                  // (string) Sender system identity, applicable only for presence or system channel.
    "sqnum": "1",                       // (string) user defined, sent during publish function.
    "sessionid": "",                    // (string) Sender sessionid, applicable only for presence or system channel.
    "intime": 1645554960732             // (string) EPOC time of the sender at time of publish.
}
dbridges:subscribe.fail
Callback parameters

payload: (dberror object)

{
    "source": "dberror.Source" ,        // (string) Error source, Refer dberror: for details
    "code": "dberror.Code",             // (string) Error code, Refer dberror: for details
    "message": ""                       // (string) Error message if applicable.
}

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:subscribe.fail",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:channel.online
Callback parameters

payload:

null

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:channel.online",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:channel.offline
Callback parameters

payload:

null

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:channel.offline",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:channel.removed
Callback parameters

payload:

null

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:channel.removed",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:unsubscribe.success
Callback parameters

payload:

null

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:unsubscribe.success",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:unsubscribe.fail
Callback parameters

payload: (dberror object)

{
    "source": "dberror.Source" ,        // (string) Error source, Refer dberror: for details
    "code": "dberror.Code",             // (string) Error code, Refer dberror: for details
    "message": ""                       // (string) Error message if applicable.
}

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:unsubscribe.fail",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:resubscribe.success
Callback parameters

payload:

null

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:resubscribe.success",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:resubscribe.fail
Callback parameters

payload: (dberror object)

{
    "source": "dberror.Source" ,        // (string) Error source, Refer dberror: for details
    "code": "dberror.Code",             // (string) Error code, Refer dberror: for details
    "message": ""                       // (string) Error message if applicable.
}

metadata (dict):

{
    "channelname": "channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:resubscribe.fail",// (string) eventName 
    "sourcesysid": "",                  // (string) 
    "sqnum": "",                        // (string) 
    "sessionid": "",                    // (string) 
    "intime":                           // (string) 
}
dbridges:participant.joined

This will be triggered only for presence (prs:) and system (sys:) channel subscription.

Callback parameters

payload: (dict)

{
  "sessionid": "ydR27s3Z92yQw7wjGY2lX",     // (string) Session id of the member who has subscribed/connected to channel
  "libtype": "nodejs",                      // (string) Library Lang of the member who has subscribed/connected to channel
  "sourceipv4": "0.0.0.0",                  // (string) IPv4 of the member who has subscribed/connected to channel
  "sourceipv6": "::1",                      // (string) Not Applicable in this version
  "sysinfo": '{"sysid":"nameofcaller"}'     // (string) System Info of the member who has subscribed/connected to channel
}

metadata (dict):

{
    "channelname": "prs:channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:participant.joined",// (string) eventName 
    "sourcesysid": "nameofcaller",          // (string) Sys id of the member who has subscribed/connected to channel
    "sqnum": null,                          // (string) 
    "sessionid": "ydR27s3Z92yQw7wjGY2lX",   // (string) Session id of the member who has subscribed/connected to channel
    "intime": null                          // (string) 
}
dbridges:participant.left

This will be triggered only for presence (prs:) and system (sys:) channel subscription.

Callback parameters

payload: (dict)

{
  "sessionid": "ydR27s3Z92yQw7wjGY2lX",     // (string) Session id of the member who has subscribed/connected to channel
  "libtype": "nodejs",                      // (string) Library Lang of the member who has subscribed/connected to channel
  "sourceipv4": "0.0.0.0",                  // (string) IPv4 of the member who has subscribed/connected to channel
  "sourceipv6": "::1",                      // (string) Not Applicable in this version
  "sysinfo": '{"sysid":"nameofcaller"}'     // (string) System Info of the member who has subscribed/connected to channel
}

metadata (dict):

{
    "channelname": "prs:channelName" ,      // (string) channelName to which subscription is done.
    "eventname": "dbridges:participant.left",// (string) eventName 
    "sourcesysid": "nameofcaller",          // (string) Sys id of the member who has subscribed/connected to channel
    "sqnum": null,                          // (string) 
    "sessionid": "ydR27s3Z92yQw7wjGY2lX",   // (string) Session id of the member who has subscribed/connected to channel
    "intime": null                          // (string) 
}
System events - payload (dberror object) - details:
Source Code Description
DBNET_CHANNEL_SUBSCRIBE ERR_FAIL_ERROR dataBrdiges network encountered error when subscribing to the channel.
DBNET_CHANNEL_SUBSCRIBE ERR_ACCESS_DENIED dBrdige network reported access violation with access_token function during subscription of this channel.
DBNET_CHANNEL_UNSUBSCRIBE ERR_FAIL_ERROR dataBrdiges network encountered error when unsubscribing to the channel.
DBNET_CHANNEL_UNSUBSCRIBE ERR_ACCESS_DENIED dataBrdiges network reported access violation with access_token function during unsubscribing of this channel.