Question

How should I best utilize the state object in a cloud function?

Environment

Cloud function connectors.

Answer

• Ensure your function is always expecting an empty ‘state’ object on first invocation of the function, so can handle scenarios where the ‘state’ is null
• Ensure your function iterates the value returned from the ‘state’ object on every subsequent invocation of the function where the ‘state’ object is not null

Example pseudo-code for this scenario:

// Request

if (req.body.state.value = null) {

hostname = endpoint.com

Path = /giveMeEverything

        }

else {

hostname = endpoint.com

Path = /value

       }

// Response

 state: {

                value: value == null ? req.state.value : value

            }

Context:

The "state" object is what your function will use to maintain cursoring,

For example:

• On the initial run of a function, the ‘state’ will be passed as an empty string to the function:
• { }
• If your cursor is keyed on a date and the last date you received in the response from the source system was 01/01/21, you would pass the following back to Fivetran:
• {"state":01/01/21}
• On the next run, this will be passed into the function as part of that initial invocation from Fivetran:
• {"state":01/01/21}

• Given you want to run from 02/01/21, you will then have logic in your function that will allow for that:
• {"state":(01/01/21 + 1)}

Considerations

Whilst you do not have to utilise the ‘state’ object, Fivetran does require a JSON string passed back including that object.