Nested object serialization using Application SDK

Ask the Community
1

I have created a simple ontology with four objects - one primary object and three others that are foreign key-linked to the primary object. I would like to configure an existing API to consume data from Palantir Foundry. How can I use the SDK to serialize a primary object and each of its nested, foreign key-related objects to JSON?

2

There is a Build with AIP package called Getting Started with Ontology SDK (OSDK) which is a very good example of how to achieve this. You can simply install it and follow the tutorial. There are more details about it in the announcements here: https://www.palantir.com/docs/foundry/announcements/#introducing-build-with-aip-for-ontology-sdk

You should find Build with AIP under YOUR_STACK_URL/workspace/now/platform

3

+1 on using the Ontology SDK (Look for Developer Console application on your Foundry instance).

Depending on your language of choice you will get something like this:

curl -X GET "https://<YOUR-STACK>/api/v2/ontologies/objects/{PrimaryObjectApiName}/{primaryKey}/links/{Name-of-the-link}" \
    -H "Authorization: Bearer $TOKEN"

Or in TypeScript

import { GetLinkedObjectError, Result } from "@osdksampleapp/sdk";
import { Flight, Aircraft } from "@osdksampleapp/sdk/ontology/objects";

function getLinkedAircraft(source: Flight) {
    return source.assignedAircraft.fetchOneWithErrors();
}
4

Thanks for your replies. I’ve stepped through the tutorial, but my question has more to do with retrieving data from multiple foreign key related objects in a single pass.

I am working on a solution for commercial lenders. In Foundry, I’ve created a primary object called Loan and have linked to it related objects called Borrower, Lender, and Collateral data.

Using the SDK, can I query a loan and get back all of these related objects?

For context, our application is written using Django/DRF and I’m trying to determine how we can leverage Palantir Foundry in our existing stack.

5

I don’t think you can retrieve an object and other linked objects at the same time. You would need one query for each distinct object type. When you create a Developer Console application, docs are generated with your object types, so you would get code snippets showing how you can get the linked objects from a Loan.

For instance, retrieving the borrower from the loan object could look like this in python:

from my_app_sdk.ontology.objects import Loan

def getLinkedBorrower(loan: Loan):
    return loan.borrower.get()

If you have many 1-to-1, or many-to-one links, you could consider flattening your ontology for convenience: for instance by adding the Borrower and Lender properties directly to the Loan object type, so you would only need to query Loan.

6

If you want to all nested object (could be a large set) given a single top level object you can write a Function On Object function (TypeScript and soon Python) which get the root object key and get all the children and return them in a JSON or some other set.
If you mark this function as a Query and give it an API name you can add it to your SDK and use it in your APP or REST call.
See docs on Query.

1 Like