使用条件查询参数构建URL

Question

我有这样简单的url builder:

prepareUrl : Params -> String
prepareUrl params = 
   Url.crossOrigin "http://someapi.com/"
    ["posts"]
    [ 
    , Url.string "currency" params.currency
    , Url.string "members[0][birthday]" "12.12.1989"
    ]

当我收到像memberCount 2或3之类的param时,我需要在请求中"克隆"成员[],如下所示:

params.membersCount = 3

prepareUrl : Params -> String
    prepareUrl params = 
       Url.crossOrigin "http://someapi.com/"
        ["posts"]
        [ 
        , Url.string "currency" params.currency
        , Url.string "members[0][birthday]" "12.12.1989"
        , Url.string "members[1][birthday]" "12.12.1989"
        , Url.string "members[2][birthday]" "12.12.1989"
        ]

日期字符串本身可以保持不变,也没关系.我怎样才能做到这一点？

Answer 1

由于第三个参数Url.Builder.crossOrigin需要的列表QueryParameter值,你可以建立一个列表0来memberCount使用List.range:

prepareUrl : Params -> String
prepareUrl params = 
   Url.crossOrigin "http://someapi.com/"
    ["posts"]
    (Url.string "currency" params.currency :: birthdayParams params.memberCount)

birthdayParams : Int -> List Url.QueryParameter
birthdayParams memberCount =
    List.range 0 (memberCount - 1)
        |> List.map (\i -> Url.string ("members[" ++ String.fromInt i ++ "][birthday]") "12.12.1989")