Access calculation from relation caluclation.

I got a resource A the defines

  calculate :access_count, :integer, Accounts.User.Calculations.AccessCount do
      public? true
    end

  calculate :access_count, :integer, Accounts.User.Calculations.AccessCount do
      public? true
    end

And I got resource B that want to expose the same field through the association

  calculate :access_count, :integer, expr(b.access_count) do
      public? true
      sortable? true
    end

  calculate :access_count, :integer, expr(b.access_count) do
      public? true
      sortable? true
    end

Looks like I cannot do this, should I just define the original calculation in B instead?

18 Replies

Marco Dell'OlioOP•3mo ago

The reason I need to expose the same attribute is to being able to sort B by that specific field

ZachDaniel•3mo ago

You can do it but only if they are all expression calculations

Marco Dell'OlioOP•3mo ago

no that source calcualtion is a module

ZachDaniel•3mo ago

It can still be an expression calculation Just has to define expression/2

Marco Dell'OlioOP•3mo ago

ok so has to be exclusively at the database level

ZachDaniel•3mo ago

Yep

Marco Dell'OlioOP•3mo ago

Thanks i'm not sure if a bug but setting the share context in the parent resource

 prepare fn query, context ->
        query
        |> Ash.Query.set_context(%{
          shared: %{time_range: query.arguments[:time_range]}
        })
      end

 prepare fn query, context ->
        query
        |> Ash.Query.set_context(%{
          shared: %{time_range: query.arguments[:time_range]}
        })
      end

this context is available in def calculate(records, _opts, context) do but not in def expression(opts, context) do

ZachDaniel•3mo ago

in the source_context key? May be a bug yes

Marco Dell'OlioOP•3mo ago

one more thing I thought that implementing def expression(_opts, context) do would automatically run it but is still asking to implement calculate I can take care of that bug

ZachDaniel•3mo ago

You shouldn't have to implement calculate

Marco Dell'OlioOP•3mo ago

 
** (UndefinedFunctionError) function OrganizationMembership.Calculations.AccessCount.calculate/3 is undefined or private

 
** (UndefinedFunctionError) function OrganizationMembership.Calculations.AccessCount.calculate/3 is undefined or private

    calculate :access_count,
              :integer,
              OrganizationMembership.Calculations.AccessCount do
      public? true
      sortable? true
    end

    calculate :access_count,
              :integer,
              OrganizationMembership.Calculations.AccessCount do
      public? true
      sortable? true
    end

fwiw this is loaded from. graphql query

ZachDaniel•3mo ago

🤔 question what if you do mix compile --force? Can I see the calculation?

Marco Dell'OlioOP•3mo ago

  def expression(_opts, context) do
    time_range = context.source_context.time_range

    expr(
      count(
        user.access_logs,
        cond do
          ^time_range == :today ->
            expr(
              user.access_logs.last_accessed_at >= start_of_day(today()) and
                user.access_logs.last_accessed_at <= date_add(start_of_day(today()), 1, :day)
            )

          ^time_range == :week ->
            expr(
              user.access_logs.last_accessed_at >= start_of_week(today()) and
                user.access_logs.last_accessed_at <= date_add(start_of_week(today()), 1, :week)
            )

          ^time_range == :month ->
            expr(
              user.access_logs.last_accessed_at >= start_of_month(today()) and
                user.access_logs.last_accessed_at <= date_add(start_of_month(today()), 1, :month)
            )
        end
      )
    )
  end

  def expression(_opts, context) do
    time_range = context.source_context.time_range

    expr(
      count(
        user.access_logs,
        cond do
          ^time_range == :today ->
            expr(
              user.access_logs.last_accessed_at >= start_of_day(today()) and
                user.access_logs.last_accessed_at <= date_add(start_of_day(today()), 1, :day)
            )

          ^time_range == :week ->
            expr(
              user.access_logs.last_accessed_at >= start_of_week(today()) and
                user.access_logs.last_accessed_at <= date_add(start_of_week(today()), 1, :week)
            )

          ^time_range == :month ->
            expr(
              user.access_logs.last_accessed_at >= start_of_month(today()) and
                user.access_logs.last_accessed_at <= date_add(start_of_month(today()), 1, :month)
            )
        end
      )
    )
  end

ZachDaniel•3mo ago

do you have use Ash.Resource.Calculation in your module?

Marco Dell'OlioOP•3mo ago

yes mix compile --force didn't help i'm trying to change the implementation ok expr(count(user.access_logs)) works just fine so is an error with the expression not being raised?

ZachDaniel•3mo ago

🤔 I'm not sure, I've never seen it complain about that having expression/2 should be all you need

Marco Dell'OlioOP•3mo ago

so removing the cond block allows to raise this error

* ** (Postgrex.Error) ERROR 42725 (ambiguous_function) function date_trunc(unknown, unknown) is not unique

* ** (Postgrex.Error) ERROR 42725 (ambiguous_function) function date_trunc(unknown, unknown) is not unique

was the block not allowing the compilation of expression/2, (?) ok so I was able to resolve it remove the date builtins functions, so I assume for some reason the cond do was preventing the error to pop out

ZachDaniel•3mo ago

strange Can you open an error w/ a stacktrace where it was trying to access \.calculate?

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Access calculation from relation caluclation.

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