IoT Platform:Functions

• Boolean: The function returns the same value as the parameter.
• Number: If the parameter is set to 0, the function returns false. Otherwise, the function returns true.
• String: If the parameter is set to "true", the function returns true. Otherwise, the function returns false.
• If the parameter is set to null, the function returns false.

• Boolean: If the parameter is set to true, the function returns 1. If the parameter is set to false, the function returns 0.
• Number: The function returns the same value as the parameter.
• String: The function parses the string to a number.
• If the parameter is set to null, the function returns 0.

If the parameter is set to a value other than null, the function returns the value as a string. If the parameter is set to null, the function returns an empty string.

If the parameter is of the binary type, the function returns a UTF-8 decoded value.

• Map: The function returns the same value as the parameter.
• String: The function parses the string to a map in the JSON format.
• If the parameter is set to null, the function returns an empty map.

• Array: The function returns the same value as the parameter.
• String: The function parses the string to an array in the JSON format.
• If the parameter is set to null, the function returns an empty array.

• Binary: The function returns the same value as the parameter.
• String: The function returns a UTF-8 encoded value.
• If the parameter is set to null, the function returns an empty binary value.

• timestamp: the timestamp in milliseconds.
• pattern: the format to which you want to convert the timestamp. Example: yyyy-MM-dd HH:mm:ss.
• timeZone: the time zone. Examples: GMT, UTC, and CST. If you do not configure this parameter, the time zone of the current system is used.

• dateString: the time string.
• pattern: the time format. Example: yyyy-MM-dd HH:mm:ss.
• timeZone: the time zone. Examples: GMT, UTC, and CST. If you do not configure this parameter, the time zone of the current system is used.

tag: This parameter is optional. If you specify a tag, the tag is added to all messages that are forwarded to the AMQP consumer group.

data: the data that you want to forward to Function Compute.

tag: This parameter is optional. If you specify a tag, the tag is added to all messages that are forwarded to Message Queue for Apache RocketMQ. You can filter messages based on tags on your consumer client.

• data: the data that you want to write to OTS instances. Only the map data type is supported. The key specifies the table column name and the value specifies the column value.

  The data parameter must contain the primary key of OTS.

• flowType: This parameter is optional. This parameter specifies the data type of fields that are not primary keys.
  • If the value of the flowType parameter is true, the system converts the values of non-primary-key fields to strings, and then forwards the strings to OTS.
  • If the value of the flowType parameter is false, the system forwards the values of non-primary-key fields to OTS but does not convert the data types.

• timeInUs: the timestamp that indicates the time when data is submitted. Unit: microseconds. Data type: integer.
• metricName: the name of a physical quantity or metric for data in a time series. Data type: string.
• tags: the tag of the time series. Data type: map. The key and value of a tag are strings.
• fields: the data in the time series. Data type: map. Multiple data values can be specified at a point in time in a time series. Each value corresponds to a column in the time series table, including the column name and column value.

  Column names are strings, and column values can be of the Boolean, integer, floating-point, string, and binary data types.

• dataSource: the identifier of the data source that is used to generate the time series. Data type: string. Only this parameter can be left empty.

You can use this function to write data in a row of OTS. To write data in multiple rows at a time, use the following function:

writeTableStoreTs(destinationId, [
    {
        "timeInUs": timestamp() * 1000,
        "metricName": "name1",
        "tags":{},
        "fields":{},
        "dataSource": ""
    },
    {
        "timeInUs": timestamp() * 1000,
        "metricName": "name2",
        "tags":{},
        "fields":{},
        "dataSource": ""
    }
]);

For more information about the parameters, see Overview.

data: the data that you want to write to ApsaraDB RDS. Only the map data type is supported. The key specifies the table column name and the value specifies the column value.

• timestamp: the timestamp.
• metricName: the name of the metric that is stored in Lindorm.
• value: the value of the data point that is stored in Lindorm. The string and map data types are supported.
• tag: the tag in the format of a key-value pair. Data type: map.

Topic: the destination topic to which you want to forward data. The following topics are supported:

• Custom topic: You must set the permission on the custom topic to subscribe. This allows devices to subscribe to the topic and obtain forwarded messages from the topic.
• Topic to which downstream TSL data is sent: /sys/${productKey}/${deviceName}/thing/service/property/set. IoT Platform forwards messages to this topic. The messages include commands to configure device properties. Devices receive the forwarded messages from the topic and configure device properties based on the payload of the messages. If you want to configure properties for the devices of the destination topic based on forwarded data, you can set the Topic parameter to this value.

The value of the ${productKey} variable must be the same as the ProductKey of the product that you specified in the destinationId parameter. You must specify a topic for the function. The topic name cannot contain wildcards.

For more information, see Create a data destination.

A Boolean value is returned.

You can configure one or more fields in the function. Multiple fields must be configured based on levels. The function returns the value of the last field. If the last field does not exist or the field is left empty, the function returns null.

Example of data:

"items": {
    "Humidity": {
        "value": 25,
        "time": 1626948134319
    }
}

Examples of the function:

• getOrNull(data, "items"): returns the value of the items field "Humidity": {"value": 25,"time": 1626948134319}.
• getOrNull(data, "items", "Humidity", "value"): returns the value of the value field 25.
• getOrNull(data, "items", "Temperature"): returns the value null when the Temperature field does not exist.

• If you do not configure the parameter, the message payload is converted to a UTF-8 encoded string. payload() is equivalent to payload('utf-8').
• If you set the parameter to 'json', the message payload is converted to a map. If the payload is not in the JSON format, an error occurs.
• If you set the parameter to 'binary', the message payload is converted to pass-through binary data.