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FairCom MQ "listTopics"

JSON MQ "listTopics" action returns and filters a list of MQTT topics

The "listTopics" action lists the names of MQTT topics that the server is tracking.

Essential information

  • You can return a filtered list by specifying a partial name in the "partialName" property.

  • You can include additional items in the list by searching for words contained in the item’s metadata.

  • Use "describeTopics" to get detailed information about specific MQTT topics.

Request examples

Minimal request

{
  "api": "mq",
  "authToken": "replaceWithAuthtokenFromCreateSession",
  "action": "listTopics"
}

Maximal request

{
  "api": "mq",
  "apiVersion": "1.0",
  "authToken": "replaceWithAuthtokenFromCreateSession",
  "requestId": "2",
  "action": "listTopics",
  "params": {
    "partialName": "test",
    "search": null,
    "dataFormat": "arrays",
    "skipRecords": null,
    "maxRecords": 20
  }
}

Response examples

Minimal response

{
  "authToken": "authToken",
  "result": {
    "data": [
      "test/ReasonCodes",
      "test/SharedSubscriptions",
      "test/topic1",
      "test/topic2"
    ]
  },
  "errorCode": 0,
  "errorMessage": ""
}

Maximal response

{
  "authToken": "authToken",
  "result": {
    "data": [
      "test/ReasonCodes",
      "test/SharedSubscriptions",
      "test/topic1",
      "test/topic2"
    ]
  },
  "requestId": "2",
  "errorCode": 0,
  "errorMessage": ""
}

The listTopics action lists the names of MQTT topics that the server is tracking

API actionJSON MQ APIjsonActionlist topicslistTopics

"params"

The "params" property is an object that contains an action's parameters. Each action defines its own required and optional properties.

Properties summary

Table 1. "params" properties summary

Property

Description

Default

Type

Limits (inclusive)

partialName

filters the returned topics by applying partial matches to their names

""

string

0 to 64 bytes



"partialName"

The "partialName" property is an optional string that causes the server to include items in the result when the beginning of their names match the "partialName" value. It defaults to an empty string.

Essential information

  • A zero-length string matches all names.

  • The "partialName" property is used to filter results in several actions used to return lists.

"result"

Properties summary

Table 2. "result" properties summary

Property

Description

Type

Limits (inclusive)

data

specifies an array or object that the server returns, such as records returned by a query. It is always included in a response but contains an empty array when no results are available.

It is an empty array when there are no results available

array

Its contents are determined by the action