check fields presence

Checks whether the specified fields are present in the incoming message data and/or metadata. By default, the node requires all specified fields to be present; you can switch to “at least one” mode.

Preconditions

Incoming message data must be a JSON object.

Configuration

Field descriptions

• Message field names — optional. A set of top-level JSON field names to look for in the message data.
• Metadata field names — optional. A set of metadata key names to look for in the message metadata.

Requirement: Although each set is optional, at least one of them must be provided with at least one field (i.e., at least one set must be non-empty).

• Check that all specified fields are present — toggle.
  • Enabled: route True only if all listed message/metadata fields are present.
  • Disabled: route True if at least one listed message/metadata field is present.

JSON Schema

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{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "TbCheckMessageNodeConfiguration",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "messageNames": {
      "description": "Field names to check in the message data.",
      "type": "array",
      "items": {
        "type": "string",
        "minLength": 1
      },
      "uniqueItems": true
    },
    "metadataNames": {
      "description": "Field names to check in the message metadata.",
      "type": "array",
      "items": {
        "type": "string",
        "minLength": 1
      },
      "uniqueItems": true
    },
    "checkAllKeys": {
      "description": "If true, require all listed fields. If false, require at least one.",
      "type": "boolean",
      "default": true
    }
  },
  "anyOf": [
    {
      "properties": {
        "messageNames": {
          "minItems": 1
        }
      }
    },
    {
      "properties": {
        "metadataNames": {
          "minItems": 1
        }
      }
    }
  ]
}

Message processing algorithm

1. Extract data as a JSON object and metadata as key–value pairs.
2. Evaluate presence:
   • If Check all keys is enabled: route True if every listed field in messageNames exists in data and every listed field in metadataNames exists in metadata.
   • If Check all keys is disabled: route True if any listed field exists in data or metadata.
3. Otherwise, route False. If an error occurs (e.g., payload is not a JSON object), route Failure.

• Only top-level keys are checked; nested paths (e.g., sensor.temp) are not supported.
• Presence means the key exists, regardless of its value (including null or empty string).

Output connections

• True:
  • If the configured presence condition is satisfied.
• False:
  • If the configured presence condition is not satisfied.
• Failure:
  • If the incoming message data cannot be parsed as a JSON object
  • If another unexpected error occurred during message processing.

Examples

The examples below show only the relevant fields of the incoming message. Unless explicitly stated otherwise, other message fields may have any values.

Example 1 — All required data fields present → True

Incoming message

Data:

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{
  "temp": 22.5,
  "humidity": 55
}

Node configuration

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{
  "messageNames": [
    "temp",
    "humidity"
  ],
  "metadataNames": [],
  "checkAllKeys": true
}

State of the system

Not relevant.

Result

Routed via True.

Explanation

Both temp and humidity exist in the payload.

Example 2 — Missing one required data field → False

Incoming message

Data:

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{
  "temp": 22.5
}

Node configuration

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{
  "messageNames": [
    "temp",
    "humidity"
  ],
  "metadataNames": [],
  "checkAllKeys": true
}

State of the system

Not relevant.

Result

Routed via False.

Explanation

humidity is not present.

Example 3 — At least one metadata field present → True

Incoming message

Metadata:

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{
  "deviceName": "Pump-42",
  "token": "abc123"
}

Node configuration

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{
  "messageNames": [],
  "metadataNames": [
    "token",
    "tenantId"
  ],
  "checkAllKeys": false
}

State of the system

Not relevant.

Result

Routed via True.

Explanation

At least one listed metadata key (token) is present.

Example 4 — At least one data field present → True

Incoming message

Data:

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{
  "temperature": 123,
  "humidity": 42
}

Metadata:

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{
  "deviceName": "Sensor-1",
  "deviceType": "TemperatureSensor"
}

Node configuration

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{
  "messageNames": [
    "temperature"
  ],
  "metadataNames": [
    "token",
    "tenantId"
  ],
  "checkAllKeys": false
}

State of the system

Not relevant.

Result

Routed via True.

Explanation

At least one listed key (temperature) is present.

Example 5 — Invalid message format → Failure

Incoming message data

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"not a JSON object"

Node configuration

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{
  "messageNames": [
    "temp"
  ],
  "metadataNames": [],
  "checkAllKeys": true
}

State of the system

Not relevant.

Result

Failure.

Explanation

Message data is not a JSON object, so the node cannot check data keys.