4 replies

Unable to run for loop within starter script

Hi,
I am using a starter script to loop over the elements of the results of a Supabase get row output.
I have set the output for the Supabase get row to be an array but when I try an loop over the elements I dont see the for loop executed.

Code in the starter script.
"""
logging.log("Inside starter script"); // Logs(Inside starter script)
logging.log("Input : "+typeof(input_array)); // Logs(Input : object)
logging.log("Input length: "+input_array.length); // Logs(Input length: 2)

for(let i=0; i< input_array.length; i++)
{
logging.log("Inside for loop"); // Not logged
logging.log("Data1:" + input_array[i]['columnA']); // Not logged
logging.log("Data2 :" + input_array[i]['columnB']); // Not logged
}
"""

When I run my workflow the first 3 logging requests are printed but code within the loop is not executed

Solution

🤖 AI Response

Your issue likely stems from the fact that the Supabase response is returning a JSON object that resembles an array (with a length property), but is not a true JavaScript array. This can happen if your database column is of type JSON/JSONB and the data structure is not strictly an array, or if the API response is being parsed in a way that results in an object rather than an array.

To handle this, you should:

- Check the actual data type returned by Supabase. If it's not a standard array, you can convert it using

Object.values(input_array)

Object.values(input_array)

to get an array of the object's values, or use

Object.keys(input_array)

Object.keys(input_array)

to iterate over its properties, as you suggested.
- Ensure your Supabase query or function returns an array if that's what you expect. If you're using a Postgres function, make sure it returns a set or array, not a JSON object with numeric keys.
- If you're storing arrays in a JSON/JSONB column, remember that Postgres supports both native arrays and JSON arrays. Native arrays are returned as arrays, while JSON/JSONB columns can store any JSON structure, including objects or arrays.

If you want to guarantee array behavior in your JavaScript code, your approach of checking with