Ontology object filter

Ask the Community
,
1

Hello,

I’m trying to filter an Ontology object and one of my filter is a preset date.
My question is, how can I use Filter on my object parameter (Timestamp) to get only those which have object.date >= SomeDate

Objects.search()
                .object1()
                .filter(f => Filters.and(f.date >= "2024-10-02" ))
                .all();

Note: For the readability the date is write as a normal date, but will be converted to Timestamp at the end.

2

Assuming that both the date property and the comparison value are actually Timestamp types:

import { Function, Timestamp } from "@foundry/functions-api";

...

Objects.search()
  .object1()
  .filter(f => f.date.range().gte(Timestamp.fromISOString("2024-10-02T00:00:00")))
  .all();

Note that if a zone offset is not explicitly specified as part of the input string (as in the above example), Timestamp.fromISOString will assume that the string represents the time in UTC.

3

Thank you, and how did I had the timezone ? (like if I got multi country with different time zone) ?

4

The answer to that question is somewhat complex.

In normal use, the Timestamp type in the Ontology represents a Unix time number, like Postgres TIMESTAMP WITH TIME ZONE, and therefore it’s not straightforward to express a filter like “include all data after 10 AM on 2024-10-02 in that data’s local timezone” as a filter on an Ontology Timestamp property when different object instances represent data in different timezones. Storing the equivalent of a Postgres TIMESTAMP WITHOUT TIME ZONE in a Timestamp property may allow you to achieve this behavior, but it would come with drawbacks, such as violating assumptions made by Foundry front-ends that the value is indeed a Unix time number. There is a good answer on Stack Overflow that explains these concepts in the context of Postgres.

However, I infer from the language of your original question that your specific need is to filter to all data for which the date part of a Timestamp in that Timestamp’s local time zone is after a specific calendar date. If that’s correct, the standard convention in Ontology design is to have two separate properties - a Timestamp that stores the Unix time number, and a Date that represents the calendar date in the time zone associated with the data. You can then express the filter using the below code:

import { Function, LocalDate } from "@foundry/functions-api";

...

Objects.search()
  .object1()
  .filter(f => f.date.range().gte(LocalDate.fromISOString("2024-10-02")))
  .all();