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elm-0.19-workshop/advanced/part5/src/PaginatedList.elm
2018-08-13 23:15:40 -04:00

90 lines
1.7 KiB
Elm

module PaginatedList exposing (PaginatedList, fromList, fromRequestBuilder, map, page, total, values)
import Html exposing (Html, a, li, text, ul)
import Html.Attributes exposing (class, classList, href)
import Html.Events exposing (onClick)
import Http
import HttpBuilder exposing (RequestBuilder)
import Task exposing (Task)
-- TYPES
type PaginatedList a
= PaginatedList
{ values : List a
, total : Int
, page : Int
}
-- INFO
values : PaginatedList a -> List a
values (PaginatedList info) =
info.values
total : PaginatedList a -> Int
total (PaginatedList info) =
info.total
page : PaginatedList a -> Int
page (PaginatedList info) =
info.page
-- CREATE
fromList : Int -> List a -> PaginatedList a
fromList totalCount list =
PaginatedList { values = list, total = totalCount, page = 1 }
-- TRANSFORM
map : (a -> a) -> PaginatedList a -> PaginatedList a
map transform (PaginatedList info) =
PaginatedList { info | values = List.map transform info.values }
-- HTTP
{-| I considered accepting a record here so I don't mess up the argument order.
-}
fromRequestBuilder :
Int
-> Int
-> RequestBuilder (PaginatedList a)
-> Task Http.Error (PaginatedList a)
fromRequestBuilder resultsPerPage pageNumber builder =
let
offset =
(pageNumber - 1) * resultsPerPage
params =
[ ( "limit", String.fromInt resultsPerPage )
, ( "offset", String.fromInt offset )
]
in
builder
|> HttpBuilder.withQueryParams params
|> HttpBuilder.toRequest
|> Http.toTask
|> Task.map (\(PaginatedList info) -> PaginatedList { info | page = pageNumber })
-- VIEW