AWS IoT Twin Maker - read data from Entities

Question

Am new to IoT Twin Maker. I have an entity that has a component with properties humidity and temperature. Am able to test this component and am getting results successfully.
I need to write a Lambda function that will ready this JSON, do a formatting and expose the JSON via REST API. What steps should I follow? Any sample code would help.

I tried creating a lambda function as

response = client.get_property_value(
    componentName='string',
    componentTypeId='string',
    entityId='string',
    selectedProperties=[
        'string',
    ],
    workspaceId='string'
)

Am getting the error "An error occurred (ValidationException) when calling the GetPropertyValue operation: No attributePropertyValueReaderByEntity connector defined for a query within entity : <>
Am sure am missing something, please guide.

Answer

Hi,

it seems that the connector you are using does not support `get_property_value`.  You can try if `get_property_value_history` is working. Not every connector supports necessarily both methods.

Cheers,  
Philipp

Answer

You may also need to check your component type model: for GetPropertyValue on properties marked as "isStoredExternally": true you should have an attributePropertyValueReaderByEntity definition under the functions in your component type (e.g. instead of "dataReader" in this example)

The lambda function used to implement the above reader should follow this request/response interface: docs

johnnyw-aws

answered a year ago

The lambda function used to implement the above reader should follow this request/response interface: [docs](https://docs.aws.amazon.com/iot-twinmaker/latest/guide/data-connector-interfaces.html#AttributePropertyValueReaderByEntity-connector)

AWS IoT Twin Maker - read data from Entities

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