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elm-0.19-workshop/advanced/part7/src/PaginatedList.elm
Richard Feldman bc62d92609 Add part7
2018-08-13 06:46:26 -04:00

99 lines
2.0 KiB
Elm

module PaginatedList exposing (PaginatedList, fromList, map, mapPage, page, total, values, view)
import Html exposing (Html, a, li, text, ul)
import Html.Attributes exposing (class, classList, href)
import Html.Events exposing (onClick)
-- 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 }
mapPage : (Int -> Int) -> PaginatedList a -> PaginatedList a
mapPage transform (PaginatedList info) =
PaginatedList { info | page = transform info.page }
-- VIEW
view : (Int -> msg) -> PaginatedList a -> Int -> Html msg
view toMsg list resultsPerPage =
let
totalPages =
ceiling (toFloat (total list) / toFloat resultsPerPage)
activePage =
page list
viewPageLink currentPage =
pageLink toMsg currentPage (currentPage == activePage)
in
if totalPages > 1 then
List.range 1 totalPages
|> List.map viewPageLink
|> ul [ class "pagination" ]
else
Html.text ""
pageLink : (Int -> msg) -> Int -> Bool -> Html msg
pageLink toMsg targetPage isActive =
li [ classList [ ( "page-item", True ), ( "active", isActive ) ] ]
[ a
[ class "page-link"
, onClick (toMsg targetPage)
-- The RealWorld CSS requires an href to work properly.
, href ""
]
[ text (String.fromInt targetPage) ]
]