xSHYNE
xSHYNE
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AEAsh Elixir
Created by xSHYNE on 8/10/2023 in #support
DISTINCT ON LEAST() GREATEST()
SELECT DISTINCT ON (LEAST(author_id, recipient_id), GREATEST(author_id, recipient_id)) id, text, author_id, recipient_id FROM private_messages WHERE author_id = ? OR recipient_id = ? ORDER BY LEAST(author_id, recipient_id), GREATEST(author_id, recipient_id), inserted_at DESC; This is the query that I would like to run. I am not quite sure after combing through the Ash docs, unfortunately Ash.Query.distinct([:author_id, recipient_id]) does not quite get me what I am looking for. The point of this query is to hydrate a view in my application similar to whatsapp, groupme, facebook messages that displays for each user you have messages with the last message sent. The way I set my database up I did not create an inbox for each user which would have made this a ton easier. Instead I have a private message that has exactly whats listed above, an id, text, author_id, recipient_id and an inserted_at. I want to basically do a window function or distinct and grab the greatest inserted at for each unique combination of author and recipient. A conversation would be englishified by saying that its all private_messages for a user_id that is equal to the author_id OR the recipient_id Is there an easier way to go about doing this? If not, how do I even run this as a fragment? Is it possible to return my PrivateMessage resource as a result? I realize I could solve all of this by reworking my database, and I'm more than willing to do that, the thing is I know I'll need to be doing these sorts of queries in the future for analytics purposes as well. Any suggestions? I've spun my head around this for a bit.
7 replies
AEAsh Elixir
Created by xSHYNE on 7/20/2023 in #support
Policy checks on related resources
I have been looking for quite some time so this may be a noob ish question. I have a couple answers potentially but I'd like to know kind of the standard way to write a policy for a resource where the relationship to that resource is how I would authorize the actor. For example Let's say I have a GroupRequest resource which represents a users request to join a group (contains a group_id and user_id) I also have a Group that has a group_admin relationship which belongs to a user. I'd only like actions occuring on a GroupRequest to be performed by the group_admin (and other similar resources such as GroupUser or GroupMembership) So the way I'd like to authorize the actor is via 
authorize_if(relates_to_actor_via([:group, :group_admin]))
authorize_if(relates_to_actor_via([:group, :group_admin]))
which I believe is giving me what I want. but I can't seem to figure out how to write a policy for a create_action in the same way. Lets say for a create action I'd like to "destroy" or "update" a group_request and then create the group_membership, but I'm not sure how to write a policy that does this. A simple check seems correct but how do I pass the group_id from the create action into the check? Did I go about this the wrong way? I also read I could potentially do a calculations field on any "group" related resource which loads the admin and then I do a check with the actor against that? What's the best scenario here?
10 replies
AEAsh Elixir
Created by xSHYNE on 7/13/2023 in #support
manage_relationship argument not relating primary key to resource
resource 
  create :add_to_group do
    argument :group, :uuid do
      allow_nil? false
    end

    change manage_relationship(:group, type: :append_and_remove)
    change relate_actor(:member)
  end
end

relationships do
  belongs_to(:group, Digsync.Accounts.Group, primary_key?: true, allow_nil?: false)
  belongs_to(:member, Digsync.Accounts.User, primary_key?: true, allow_nil?: false)
end
  create :add_to_group do
    argument :group, :uuid do
      allow_nil? false
    end

    change manage_relationship(:group, type: :append_and_remove)
    change relate_actor(:member)
  end
end

relationships do
  belongs_to(:group, Digsync.Accounts.Group, primary_key?: true, allow_nil?: false)
  belongs_to(:member, Digsync.Accounts.User, primary_key?: true, allow_nil?: false)
end
changeset after GroupMembership |> Ash.Changeset.for_create(:add_to_group, %{group: group_id}) 
#Ash.Changeset<
action_type: :create,
action: :add_to_group,
attributes: %{},
relationships: %{
  group: [
    {"b6937067-651d-4385-8323-20f193f03cd9",
     [
       ignore?: false,
       on_missing: :unrelate,
       on_match: :ignore,
       on_lookup: :relate,
       on_no_match: :error,
       eager_validate_with: false,
       authorize?: true,
       meta: [inputs_was_list?: false, id: :group],
       type: :append_and_remove
     ]}
  ],
  member: [
    {[
       #Digsync.Accounts.User<
         id: "b86d7074-a35a-4df6-8eac-a60327cc254f",
       >
     ],
     [
       ignore?: false,
       on_missing: :unrelate,
       on_match: :ignore,
       on_lookup: :relate,
       on_no_match: :error,
       eager_validate_with: false,
       authorize?: true,
       type: :append_and_remove,
       meta: [inputs_was_list?: false]
     ]}
  ]
},
arguments: %{group: "b6937067-651d-4385-8323-20f193f03cd9"},
errors: [],
>,
valid?: true
>
#Ash.Changeset<
action_type: :create,
action: :add_to_group,
attributes: %{},
relationships: %{
  group: [
    {"b6937067-651d-4385-8323-20f193f03cd9",
     [
       ignore?: false,
       on_missing: :unrelate,
       on_match: :ignore,
       on_lookup: :relate,
       on_no_match: :error,
       eager_validate_with: false,
       authorize?: true,
       meta: [inputs_was_list?: false, id: :group],
       type: :append_and_remove
     ]}
  ],
  member: [
    {[
       #Digsync.Accounts.User<
         id: "b86d7074-a35a-4df6-8eac-a60327cc254f",
       >
     ],
     [
       ignore?: false,
       on_missing: :unrelate,
       on_match: :ignore,
       on_lookup: :relate,
       on_no_match: :error,
       eager_validate_with: false,
       authorize?: true,
       type: :append_and_remove,
       meta: [inputs_was_list?: false]
     ]}
  ]
},
arguments: %{group: "b6937067-651d-4385-8323-20f193f03cd9"},
errors: [],
>,
valid?: true
>
** (Ash.Error.Invalid) Input Invalid

* record with "b6937067-651d-4385-8323-20f193f03cd9" not found
    (ash 2.11.6) lib/ash/api/api.ex:2124: Ash.Api.unwrap_or_raise!/3
** (Ash.Error.Invalid) Input Invalid

* record with "b6937067-651d-4385-8323-20f193f03cd9" not found
    (ash 2.11.6) lib/ash/api/api.ex:2124: Ash.Api.unwrap_or_raise!/3
I'm very confused, that id absolute exists and is a Group. When I do a different relationship which is coded almost identically it has a different data structure for the id: 
   action_type: :create,
   action: :create_from_flow,
   attributes: %{},
   relationships: %{
     friend_one: [
       {[%{id: "266d68e7-3a8b-401a-a616-1b42c385a811"}],
   action_type: :create,
   action: :create_from_flow,
   attributes: %{},
   relationships: %{
     friend_one: [
       {[%{id: "266d68e7-3a8b-401a-a616-1b42c385a811"}],
22 replies
AEAsh Elixir
Created by xSHYNE on 7/12/2023 in #support
Ash Admin dependency for newest liveview
Because your app depends on ash_admin ~> 0.8.1 which depends on phoenix_live_view ~> 0.18.3, phoenix_live_view ~> 0.18.3 is required.
So, because your app depends on phoenix_live_view ~> 0.19.0, version solving failed.
Because your app depends on ash_admin ~> 0.8.1 which depends on phoenix_live_view ~> 0.18.3, phoenix_live_view ~> 0.18.3 is required.
So, because your app depends on phoenix_live_view ~> 0.19.0, version solving failed.
Anyway to solve this? or have to wait for update? create an issue?
4 replies
AEAsh Elixir
Created by xSHYNE on 7/7/2023 in #support
Ash.Query.load not loading nested relationship?
User |> Ash.Query.load([friendships: [:first, :second]])
|> Accounts.read!()

#Ash.Query<
  resource: User,
  errors: [
    %Ash.Error.Query.InvalidLoad{
      load: :first,
      changeset: nil,
      query: nil,
      error_context: [],
      vars: [],
      path: [:friendships, :load],
      stacktrace: #Stacktrace<>,
      class: :invalid
    },
    %Ash.Error.Query.InvalidLoad{
      load: :second,
      changeset: nil,
      query: nil,
      error_context: [],
      vars: [],
      path: [:friendships, :load],
      stacktrace: #Stacktrace<>,
      class: :invalid
    }
  ]
>
User |> Ash.Query.load([friendships: [:first, :second]])
|> Accounts.read!()

#Ash.Query<
  resource: User,
  errors: [
    %Ash.Error.Query.InvalidLoad{
      load: :first,
      changeset: nil,
      query: nil,
      error_context: [],
      vars: [],
      path: [:friendships, :load],
      stacktrace: #Stacktrace<>,
      class: :invalid
    },
    %Ash.Error.Query.InvalidLoad{
      load: :second,
      changeset: nil,
      query: nil,
      error_context: [],
      vars: [],
      path: [:friendships, :load],
      stacktrace: #Stacktrace<>,
      class: :invalid
    }
  ]
>
this gives an invalid load BUT: 
Friendship |> Ash.Query.load([:first, :second]) |> Accounts.read!()

  #Friendship<
    second: User<>
    first: User<> 
Friendship |> Ash.Query.load([:first, :second]) |> Accounts.read!()

  #Friendship<
    second: User<>
    first: User<>
works fine? Why can't I load nested on the parent many_to_many relationship?
19 replies