AshSync is a declarative wrapper around Phoenix.Sync meant for Ash applications.
I've laid out some patterns for what this should look like, and set up the typescript code generation process. I need someone to champion this from here on. See the #todo comments for more.
updating/deleting items in a collection does not appear to be working due to a client bug that I have not yet figured out.
the basic example app I'm working from is here: https://github.com/zachdaniel/ash_sync_example
AshSync currently expects an idiomatic front end Phoenix w/ js setup that has the following dependencies added to the package.json in assets.
"@electric-sql/react""@tanstack/db""@tanstack/db-collections""@tanstack/react-db""react""react-dom""uuid""zod"
We generate the following files, which can be used by the js in your front end.
assets/js/client/ingest.ts- used to ingest changes from tanstack db to the sync endpointassets/js/client/queries.ts- Functions to directly use shape streams from electricSQLassets/js/client/collections.ts- Functions to create ElectricCollections which sync back to sync endpointassets/js/client/schema.ts- Types for resources being synchronized
To regenerate them, use mix ash.codegen <name_for_changes>. Needing to provide a name is inconvenient. We will remove that requirement in the future.
Add the following to your router:
scope "/", MyAppWeb do
pipe_through :browser
get "/sync", SyncController, :sync
post "/ingest/mutations", SyncController, :sync_mutate
endAnd define the controller
defmodule MyAppWeb.SyncController do
use Phoenix.Controller, formats: [:html, :json]
def sync(conn, params) do
AshSync.sync_render(:my_app, conn, params)
end
def sync_mutate(conn, params) do
AshSync.sync_mutate(:my_app, conn, params)
end
enddefmodule MyApp.Blog do
use Ash.Domain,
extensions: [AshSync],
otp_app: :my_app
sync do
resource MyApp.Blog.Post do
query :list_blog_posts, :read do
on_insert :create
on_update :update
on_delete :destroy
end
end
end
resources do
resource MyApp.Blog.Post
end
endElectricSQL has a lot of limitations around what can be synchronized via shapes. This project does nothing to enable anything beyond that, so the queries you build will be limited in that way.
A major example is that you cannot join in queries that are synchronized. One way to get around this, for example, is to denormalize your data such that all of the information you need to authorize or accomplish a read is on the table itself.