Add part5

advanced/part5/src/PaginatedList.elm

@@ -0,0 +1,98 @@
+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) ]
+        ]