Override total_entries and total_pages

[coreyk]

I have a use case where i need to pass the total entries and total pages from a more complex query.

How can I override total_entries and total_pages from Scrivener.Ecto?
This doesn't work (from the Scrivener.Ecto README):

def index(conn, params) do
  page =
    MyApp.Person
    |> where([p], p.age > 30)
    |> order_by(desc: :age)
    |> preload(:friends)
    |> MyApp.Repo.paginate(params)

  render conn, :index,
    people: page.entries,
    page_number: page.page_number,
    page_size: page.page_size,
    total_pages: new_page_total, # NEW TOTAL PAGES, CALCULATED ELSEWHERE
    total_entries: new_entry_total # NEW TOTAL ENTRIES, CALCULATED ELSEWHERE
end

[coreyk]

I guess if you do this it works:

def index(conn, params) do
  page =
    MyApp.Person
    |> where([p], p.age > 30)
    |> order_by(desc: :age)
    |> preload(:friends)
    |> MyApp.Repo.paginate(params)

  meow = %Scrivener.Page{entries: page.entries,
    page_number: page.page_number,
    page_size: page.page_size,
    total_pages: new_total_pages,
    total_entries: new_total_entries}

    render conn, :index, properties: meow

[mgwidmann]

Yes you could do that. However, I suppose this is more for the Scrivener project to tackle than here.
I'd just update the values rather than creating a new page...

render conn, :index, page: %{page | total_pages: new_total_pages, total_entries: new_total_entries}

But first, think about the fact that you're doing this before you do it. If the paginate function isnt giving you the data you want in those fields, ask yourself if maybe you're doing something wrong. I'd bet that @drewolson likely would want to know more about your use case in changing these values.

[coreyk]

The reason for this is to get around the limitation of Scrivener.Ecto when not selecting * and needing an accurate result count.

My queries are more complex than usual, with 6 joins, a where and a select on 10 columns across 7 tables. The count distinct can't be on *.

[mgwidmann]

either way, I'm not sure how this project should change to help you. You can already override the total_pages and total_entries like I showed, and then the helper function this project exposes will work just the same...

[drewolson]

@coreyk the newest release of scrivener_ecto uses subquery to produce accurate counts. Please take a look. This issue is unrelated to this project.