Channel Metadata
Types
The payload of metadata events for channels is the ChannelDetails type which contains the channelId and other static information about the channel, plus a status containing a ChannelStatus instance which contains information about the current state of the channel.
ChannelDetails
ChannelDetails is an object returned when requesting or receiving channel metadata. It contains information on the channel itself, along with the current state of the channel in the ChannelStatus object.
| Name | Description | Type |
|---|---|---|
| channelId | the required name of the channel including any qualifier, if any | string |
| region | in events relating to the activity of a channel in a specific region, this optionally identifies the region | string |
| isGlobalMaster | in events relating to the activity of a channel in a specific region, this optionally identifies whether or not that region is responsible for global coordination of the channel | boolean |
| status | an optional ChannelStatus instance | ChannelStatus |
The following is an example of a ChannelDetails JSON object:
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{
"channelId": "foo",
"status": {
"isActive": true,
"occupancy": {
"metrics": {
"connections": 1,
"publishers": 1,
"subscribers": 1,
"presenceConnections": 1,
"presenceMembers": 0,
"presenceSubscribers": 1,
"objectPublishers": 1,
"objectSubscribers": 1
}
}
}
}ChannelDetails.ChannelStatus
ChannelStatus is contained within the ChannelDetails object, and optionally contains an Occupancy object.
| Name | Description | Type |
|---|---|---|
| isActive | a required boolean value indicating whether the channel that is the subject of the event is active. For events indicating regional activity of a channel this indicates activity in that region, not global activity | boolean |
| occupancy | an optional Occupancy instance indicating the occupancy of the channel. For events indicating regional activity of a channel this indicates activity in that region, not global activity. | Occupancy |
ChannelDetails.ChannelStatus.Occupancy
Occupancy is optionally contained within the ChannelStatus object, and contains metadata relating to the occupants of the channel. This is usually contained within the occupancy attribute of the ChannelStatus object.
The occupancy attribute contains the metrics attribute, which contains the following members:
| Name | Description | Type |
|---|---|---|
| connections | the number of connections | integer |
| publishers | the number of connections attached to the channel that are authorised to publish | integer |
| subscribers | the number of connections attached that are authorised to subscribe to messages | integer |
| presenceSubscribers | the number of connections that are authorised to subscribe to presence messages | integer |
| presenceConnections | the number of connections that are authorised to enter members into the presence channel | integer |
| presenceMembers | the number of members currently entered into the presence channel | integer |
| objectPublishers | the number of connections that are authorised to publish updates to objects on the channel | integer |
| objectSubscribers | the number of connections that are authorised to subscribe to objects on the channel | integer |