Hello there,
I am trying to accomplish the following (apart from upserting a value depending on :apple_event_id which works)
- increment
:versionwith every upsert (also works) - only update the entry when a condition is met (
:last_modifiedhas changes) - does not work and throws error (see below)
This is the entity (everything not important has been removed):
defmodule PalmSync4Mac.Entity.EventKit.CalendarEvent do
@moduledoc """
Represents a calendar event in the Apple Calendar.
"""
use Ash.Resource,
domain: PalmSync4Mac.Entity.EventKit,
data_layer: AshSqlite.DataLayer
sqlite do
table("calendar_event")
repo(PalmSync4Mac.Repo)
end
identities do
identity(
:unique_event,
[
:apple_event_id
],
eager_check?: true
)
end
actions do
defaults([:read, :destroy])
create(:create_or_update) do
upsert?(true)
upsert_identity(:unique_event)
change(set_attribute(:version, 0))
change(atomic_update(:version, expr(version + 1)))
upsert_condition(expr(^arg(:last_modified) > last_modified))
accept([
...
:last_modified,
...
])
end
end
attributes do
uuid_primary_key(:id)
.
.
.
attribute(:last_modified, :utc_datetime) do
description("The last time the event was modified as stored by Apple")
allow_nil?(false)
public?(true)
end
attribute :version, :integer do
description("Version of the calendar event. Automatically incremented on each update")
allow_nil?(false)
public?(true)
writable?(false)
end
end
end
The function that reates the entry in the database:
defp sync_calendar(calendar, interval) do
case PalmSync4Mac.EventKit.PortHandler.get_events(calendar, interval) do
{:ok, data} ->
Enum.each(data["events"], fn cal_date ->
PalmSync4Mac.Entity.EventKit.CalendarEvent
|> Ash.Changeset.for_create(:create_or_update, cal_date)
|> Ash.create!()
end)
{:error, reason} ->
Logger.error("Error syncing calendar events: #{inspect(reason)}")
end
end
As long as the upsert_condition is commented out everything works but updates the entry everytime because of a missing constraint
With the upsert_condition commented in this is the error that I get:
03:00:00.464 [error] GenServer PalmSync4Mac.EventKit.CalendarEventWorker terminating
** (Ash.Error.Unknown)
Bread Crumbs:
> Error returned from: PalmSync4Mac.Entity.EventKit.CalendarEvent.create_or_update
Unknown Error
* ** (UndefinedFunctionError) function :parameterized.type/0 is undefined (module :parameterized is not available)
:parameterized.type()
(elixir 1.18.3) lib/enum.ex:1840: Enum."-map_reduce/3-lists^mapfoldl/2-0-"/3
(elixir 1.18.3) lib/enum.ex:2546: Enum."-reduce/3-lists^foldl/2-0-"/3
(ash 3.5.12) lib/ash/error/unknown.ex:3: Ash.Error.Unknown."exception (overridable 2)"/1
(ash 3.5.12) /Users/bsu/Development/Elixir/palm_sync_4_mac/deps/splode/lib/splode.ex:264: Ash.Error.to_class/2
(ash 3.5.12) lib/ash/error/error.ex:108: Ash.Error.to_error_class/2
(ash 3.5.12) lib/ash/actions/create/create.ex:161: Ash.Actions.Create.do_run/4
(ash 3.5.12) lib/ash/actions/create/create.ex:50: Ash.Actions.Create.run/4
(ash 3.5.12) lib/ash.ex:2272: Ash.create!/3
(elixir 1.18.3) lib/enum.ex:987: Enum."-each/2-lists^foreach/1-0-"/2
Last message: {:"$gen_cast", {:sync, 1, []}}
State: %PalmSync4Mac.EventKit.CalendarEventWorker{interval: 13, calendars: []}
My dependencies:
...
elixir: "~> 1.18",
compilers: [:unifex, :bundlex] ++ Mix.compilers(),
...
{:ash, "~> 3.5"},
{:ash_sqlite, "~> 0.2"},
...
Another question is of course also: Is upsert_condition the correct function for this?
Thanks for you help 
FYI: I have also posted this on reddit: https://www.reddit.com/r/elixir/comments/1kw052j/ash_entity_and_upset_condition_i_dont_get_it/
it wasn’t released yet. Fix released in 
