Payload Templating

This page describes the template syntax used by akenza in more detail

Payload templating allows the customization of the payload of output connectors, rule actions, and access data of the uplink as well as other metadata by making use of a templating language.

The templating language can be used to add properties of the sample to the e-mail action body and subject.

Usage

To trigger the suggestions in the UI, simply enter double open curly brackets ({{) in the input field which will show available options. Make sure to end the expression by adding double closing curly brackets (}}).

Enclosed in the curly brackets, the access to any data sample or other properties is done using the dot-notation.

Consider the following structure:

{
    "data": {
        "time": "2021-03-02T11:37:00+000",
        "temp": 23.5,
        ...
    },
    ...
}

If e.g. the temperature value of the sample is to be added in the email body, the access to this value is as follows: {{data.temp}}.

JSON Payload Templating

If the target e.g. a Webhook requires a different JSON object structure, the custom payload can be used in combination with the templating syntax to achieve a completely new JSON structure.

Consider the following structure of the sample:

{
    "data": {
        "time": "2021-03-02T11:37:00+000",
        "temp": 23.5,
        "state": "all ok",
        ...
    },
    ...
}

If the output to the webhook connector should look something like

{
    "temp": 23.5,
    "time": "2021-03-21T11:37:00+000",
    "state": "all ok",
    ...
}

The following template will achieve this:

{
    "temp": {{data.temp}},
    "time": {{data.time}},
    "state": {{data.state}},
    ...
}

NOTE: Previously all the templating expressions in JSON were enclosed in quotes in order to be a valid JSON object. This is no longer necessary since the templating engine will replace and encode/escape the value according to type.

Supported Properties

The following properties are supported:

  • data.* access any values of the sample

  • meta.* access any values of the meta object

  • result.* access any values of the custom rule logic result

  • uplinkMeta the complete uplink meta-object. See Uplink Meta Properties for sub-properties

  • topic the data topic

  • timestamp the timestamp of the sample

  • deviceId the unique device id of the device triggering the flow

  • akenzaDeviceId the akenza device id of the device triggering the flow

  • correlationId the correlation id of the flow

  • device the complete device object. See Device Properties for sub-properties

  • rule the complete rule object. See Rule Properties for sub-properties

  • uplinkMetrics the complete uplink metrics object. See uplink metrics Properties for sub-properties

  • rawData the complete raw data object. See raw data Properties for sub-properties. Only available for LoRa uplinks

  • dataSources all data source objects involved in the triggered flow. See Data Source Properties for sub-properties

Device Properties

The following properties of a device can be accessed when using template syntax.

Note: The prefix device. is always required in order to access sub-properties.

  • name the device name

  • description the device description

  • integrationId the integration Id of the device (only for LoRaWAN devices)

  • workspaceId the workspace Id of the device

  • dataFlowId the data flow Id of the device

  • connectivity the connectivity of the device

  • id the akenza device Id

  • deviceId the unique device id

  • customFields.* access Custom Fields values by their name

Rule Properties

The following properties of a rule can be accessed when using template syntax.

Note: The prefix rule. is always required in order to access sub-properties.

  • ruleId the id fo the rule

  • name the name of the rule (only for rules)

  • description the description of the rule

  • workspaceId the workspace Id of the rule

Data Source Properties

The following properties of a data source can be accessed when using template syntax.

To access a specific data source, use dataSources.X where X is the number of the data source as specified in the rule (starting at 1).

Some properties can be null in certain circumstances (e.g. the correlationId or the device) if e.g. the rule was triggered by a timer event or the data source is set to access the last sample.

Note: The prefix dataSources.X. is always required in order to access sub-properties.

  • correlationId the correlation id of the data source (only available if the data source was triggering the flow)

  • device the complete device object. See Device Properties for sub-properties

  • deviceId the unique device id

  • akenzaDeviceId the akenza device id

  • topic the topic of the sample

  • timestamp the timestamp of the sample

  • data.* access any values of the sample

  • meta.* access any values of the meta object

  • uplinkMeta the complete uplink meta object

  • trigger boolean indicates whether the data source has triggered the uplink

  • deviceInput boolean indicates if the data source is a device

  • tagInput boolean indicates if the data source is a tag

Uplink Meta Properties

The following properties of uplink metadata can be accessed when using template syntax

Note: The prefix uplinkMeta. is always required in order to access sub-properties.

  • dataReceived the ISO-8601 timestamp when the data was received

  • bytesReceived the number of bytes received in the uplink request

  • processingStart the ISO-8601 timestamp when the processing was started

  • scriptRunUplinkStart the ISO-8601 timestamp when script run was started

  • scriptRunUplinkEnd the ISO-8601 timestamp when script run ended

  • processingEnd the ISO-8601 timestamp when the processing ended

  • outputProduced the ISO-8601 timestamp when all output was produced

  • uplinkDuration the ISO-8601 duration of the whole uplink flow

  • processingDuration the IOS-8601 duration of the processing

  • scriptRunningDuration the ISO-8601 duration of the script run

Uplink Metrics Properties

The following properties of uplink metrics can be accessed when using template syntax

Note: The prefix uplinkMetrics. is always required in order to access sub-properties.

  • uplinkSize the size of the uplink

  • timestampthe ISO-8601 timestamp when the data was received

  • latitude the latitude of the device

  • longitude the latitude of the device

  • locationRadius the error radius for the location

  • port the port used when sending the uplink

  • frameCountUp the frame count up of the uplink

  • frameCountDown the frame count down of the uplink

  • rssi the rssi of the uplink

  • snr the snr of the uplink

  • sf the spreading factor used to send the uplink

  • txPower the tx power used to send the uplink

  • numberOfGateways the number of gateways that received the uplink

  • esp the esp of the uplink

  • sqi the signal quality of the uplink

  • batteryLevel the battery level of the device

Raw Data Properties

The following properties of raw data can be accessed when using template syntax

Note: The prefix rawData. is always required in order to access sub-properties.

  • port the port of the unprocessed uplink

  • payloadHex the hex payload of the unprocessed uplink

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