Messenger Plugin

Version: 1.0

Status:

Messenger plugin for Thunder framework.

Table of Contents

• Introduction
• Description
• Configuration
• Interfaces
• Methods
• Notifications

Introduction

Scope

This document describes purpose and functionality of the Messenger plugin. It includes detailed specification about its configuration, methods provided and notifications sent.

Case Sensitivity

All identifiers of the interfaces described in this document are case-sensitive. Thus, unless stated otherwise, all keywords, entities, properties, relations and actions should be treated as such.

Acronyms, Abbreviations and Terms

The table below provides and overview of acronyms used in this document and their definitions.

Acronym	Description
API	Application Programming Interface
HTTP	Hypertext Transfer Protocol
JSON	JavaScript Object Notation; a data interchange format
JSON-RPC	A remote procedure call protocol encoded in JSON

The table below provides and overview of terms and abbreviations used in this document and their definitions.

Term	Description
callsign	The name given to an instance of a plugin. One plugin can be instantiated multiple times, but each instance the instance name, callsign, must be unique.

References

Ref ID	Description
HTTP	HTTP specification
JSON-RPC	JSON-RPC 2.0 specification
JSON	JSON specification
Thunder	Thunder API Reference

Description

The Messenger allows exchanging text messages between users gathered in virtual rooms. The rooms are dynamically created and destroyed based on user attendance. Upon joining a room the client receives a unique token (room ID) to be used for sending and receiving the messages.

The plugin is designed to be loaded and executed within the Thunder framework. For more information about the framework refer to [Thunder].

Configuration

The table below lists configuration options of the plugin.

Name	Type	M/O	Description
callsign	string	mandatory	Plugin instance name (default: Messenger)
classname	string	mandatory	Class name: Messenger
locator	string	mandatory	Library name: libThunderMessenger.so
startmode	string	mandatory	Determines in which state the plugin should be moved to at startup of the framework

Interfaces

This plugin implements the following interfaces:

• IMessenger (IMessenger.h) (version 1.0.0) (compliant format)

  This interface uses legacy lowercase naming convention. With the next major release the naming convention will change to camelCase.

Methods

The following methods are provided by the Messenger plugin:

Messenger interface methods:

Method	Description
join	Joins a messaging room
leave	Leaves a messaging room
send	Sends a message to a messaging room

join ^method

Joins a messaging room.

Description

If the specified room does not exist, then it will be created.

Parameters

Name	Type	M/O	Description
params	object	mandatory	...
params.room	string	mandatory	Name of the room to join
params.user	string	mandatory	Name of ther user to join as
params?.secure	string	optional	Denotes if the room is secure (by default not secure) (must be one of the following: insecure, secure)
params?.acl	array	optional	List of URL origins with possible wildcards
params?.acl[#]	string	mandatory	...

Result

Name	Type	M/O	Description
result	string	mandatory	Token for accessing the room (unique for a user)

Errors

Message	Description
ERROR_ILLEGAL_STATE	User name is already taken (i.e. the user has already joined the room)
ERROR_BAD_REQUEST	User name or room name is invalid
ERROR_PRIVILEGED_REQUEST	Room security errors

Example

Request

{
  "jsonrpc": "2.0",
  "id": 42,
  "method": "Messenger.1.join",
  "params": {
    "room": "Lounge",
    "user": "Bob",
    "secure": "secure",
    "acl": [
      "..."
    ]
  }
}

Response

{
  "jsonrpc": "2.0",
  "id": 42,
  "result": "1e217990dd1cd4f66124"
}

leave ^method

Leaves a messaging room.

Description

The room ID becomes invalid after this call. If there are no more users, the room will be destroyed and related resources freed.

Parameters

Name	Type	M/O	Description
params	object	mandatory	...
params.roomid	string	mandatory	Token of the room to leave

Result

Name	Type	M/O	Description
result	null	mandatory	Always null

Errors

Message	Description
ERROR_UNKNOWN_KEY	The room token is invalid

Example

Request

{
  "jsonrpc": "2.0",
  "id": 42,
  "method": "Messenger.1.leave",
  "params": {
    "roomid": "1e217990dd1cd4f66124"
  }
}

Response

{
  "jsonrpc": "2.0",
  "id": 42,
  "result": null
}

send ^method

Sends a message to a messaging room.

Parameters

Name	Type	M/O	Description
params	object	mandatory	...
params.roomid	string	mandatory	Token of the room to send the message to
params.message	string	mandatory	Contents of the message to send

Result

Name	Type	M/O	Description
result	null	mandatory	Always null

Errors

Message	Description
ERROR_UNKNOWN_KEY	The room token is invalid

Example

Request

{
  "jsonrpc": "2.0",
  "id": 42,
  "method": "Messenger.1.send",
  "params": {
    "roomid": "1e217990dd1cd4f66124",
    "message": "Hello!"
  }
}

Response

{
  "jsonrpc": "2.0",
  "id": 42,
  "result": null
}

Notifications

Notifications are autonomous events triggered by the internals of the implementation and broadcasted via JSON-RPC to all registered observers. Refer to [Thunder] for information on how to register for a notification.

The following events are provided by the Messenger plugin:

Messenger interface events:

Notification	Description
roomupdate	Notifies of room status changes
userupdate	Notifies of user status changes
message	Notifies of messages sent the the room

roomupdate ^notification

Notifies of room status changes.

Description

Immediately after registering to this notification the listener will sequentially receive updates of all rooms that have been created so far.

This notification may also be triggered by client registration.

Notification Parameters

Name	Type	M/O	Description
params	object	mandatory	...
params.room	string	mandatory	Name of the room that has changed its status
params.action	string	mandatory	New room status (must be one of the following: created, destroyed)
params.secure	string	mandatory	Denotes if the room is secure (must be one of the following: insecure, secure)

Example

Registration

{
  "jsonrpc": "2.0",
  "id": 42,
  "method": "Messenger.1.register",
  "params": {
    "event": "roomupdate",
    "id": "myid"
  }
}

Notification

{
  "jsonrpc": "2.0",
  "method": "myid.roomupdate",
  "params": {
    "room": "Lounge",
    "action": "destroyed",
    "secure": "secure"
  }
}

The client ID parameter is passed within the notification designator, i.e. <client-id>.roomupdate.

userupdate ^notification

Notifies of user status changes.

Description

Immediately after registering to this notification the listener will sequentially receive updates of all users that have joined the room so far.

This notification may also be triggered by client registration.

Parameters

The roomId parameter shall be passed within the id parameter to the register call, i.e. <roomid>.<client-id>.

Notification Parameters

Name	Type	M/O	Description
params	object	mandatory	...
params.user	string	mandatory	Name of the user that has changed its status
params.action	string	mandatory	New user status (must be one of the following: joined, left)

Example

Registration

{
  "jsonrpc": "2.0",
  "id": 42,
  "method": "Messenger.1.register",
  "params": {
    "event": "userupdate",
    "id": "1e217990dd1cd4f66124.myid"
  }
}

Notification

{
  "jsonrpc": "2.0",
  "method": "1e217990dd1cd4f66124.myid.userupdate",
  "params": {
    "user": "Bob",
    "action": "left"
  }
}

The client ID parameter is passed within the notification designator, i.e. <roomid>.<client-id>.userupdate.

The roomId parameter is passed within the notification designator, i.e. <roomid>.<client-id>.userupdate.

message ^notification

Notifies of messages sent the the room.

Parameters

The roomId parameter shall be passed within the id parameter to the register call, i.e. <roomid>.<client-id>.

Notification Parameters

Name	Type	M/O	Description
params	object	mandatory	...
params.user	string	mandatory	Name of the user that has sent the message
params.message	string	mandatory	Contents of the sent message

Example

Registration

{
  "jsonrpc": "2.0",
  "id": 42,
  "method": "Messenger.1.register",
  "params": {
    "event": "message",
    "id": "1e217990dd1cd4f66124.myid"
  }
}

Notification

{
  "jsonrpc": "2.0",
  "method": "1e217990dd1cd4f66124.myid.message",
  "params": {
    "user": "Bob",
    "message": "Hello!"
  }
}

The client ID parameter is passed within the notification designator, i.e. <roomid>.<client-id>.message.

The roomId parameter is passed within the notification designator, i.e. <roomid>.<client-id>.message.