Ash Framework•2mo ago

AshObjectIds

https://hex.pm/packages/ash_object_ids An Ash implementation of the "Stripe IDs" (human readable, copyable, IDs with a prefix for the model they reference): https://dev.to/stripe/designing-apis-for-humans-object-ids-3o5a TLDR:

defmodule App.Blog.Comment do
  use Ash.Resource,
    domain: App.Blog,
    data_layer: Ash.DataLayer.AshPostgres,
    extensions: [AshObjectIds]

  alias App.Blog.Post

  object_id do
    prefix "c"
  end

  attributes do
    uuid_primary_key :id
    attribute :text, :string, public?: true, allow_nil?: false
  end

  relationships do
    belongs_to :post, Post, attribute_type: Post.ObjectId
  end
end

defmodule App.Blog.Comment do
  use Ash.Resource,
    domain: App.Blog,
    data_layer: Ash.DataLayer.AshPostgres,
    extensions: [AshObjectIds]

  alias App.Blog.Post

  object_id do
    prefix "c"
  end

  attributes do
    uuid_primary_key :id
    attribute :text, :string, public?: true, allow_nil?: false
  end

  relationships do
    belongs_to :post, Post, attribute_type: Post.ObjectId
  end
end

Externally, these are prefixed, base58-encoded UUIDs.

15 Replies

ZachDaniel•2mo ago

Nice! Don't forget to add a link to the project 😄

RandallOP•2mo ago

Haha, you're right, forgot the most important part. Added it. The only thing I wasn't sure about with this library was the use of persisters to generate the type module for each resource

Meeq•2mo ago

What would it look like to migrate from using plain UUIDs to AshObjectIds?

RandallOP•2mo ago

I did think about adding some kind of "allow raw uuids" option to provide an upgrade path. But I primarly made this lib for greenfield projects, so I hadn't added it yet

Meeq•2mo ago

The absence of a _ character in the ID should be a giveaway that it isn't an Object ID. Of course, you still need to disambiguate Object IDs that have been orphaned from their prefix vs raw UUIDs, but luckily they are encoded differently.

RandallOP•2mo ago

Yeah it shouldn't be a lot of work; it's just work I haven't done 😛

Gonzalo Muñoz•2mo ago

Hi! This is great, thanks! A nitpick about the name though: it can be confusing. At least in my experience, people who know about databases usually identify "objectId" with MongoDB's _ids. If this is only for Stripe IDs, it should be easily recognizable by its name. Same thing if it is a generic package for several types of unique identifiers. I read the article though, and they themselves call it both ways so I don't even know lol

Georges•2mo ago

Ah, I see they are stored as UUID, so theoretically, one could switch to using these without changing the database

RandallOP•2mo ago

Yes they're stored as plain UUIDs. I believe stripe actually stores them encoded and all, but I have a use case where I want to keep them UUIDv7 in the database.

Meeq•2mo ago

What benefit is there of storing as UUIDv7 in the database? Timestamp extraction?

RandallOP•2mo ago

Sorting & cursor-based pagination

Oliver•2mo ago

Hexdocs link from hex is broken @Randall

RandallOP•2mo ago

Fixed, thanks

ZachDaniel•2w ago

@Randall I'm putting this in the ash weekly news letter, do you want me to use your full name? Publishing for now but happy to edit as you like later 🙂

RandallOP•2w ago

It's fine like this

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