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68 lines
2.2 KiB
Markdown
68 lines
2.2 KiB
Markdown
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A library for fetching data from paginated JSON REST APIs.
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# Motivation
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This library is built to handle fetching data from a JSON REST API
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that paginates its results. It inspects response headers, and will
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prepare subsequent requests when additional pages of results remain.
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Given a JSON decoder for the data type returned in the paginated
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collection, it will return a data structure containing the results
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fetched, and a new request object for fetching additional records from
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the next page if more are available.
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It is expected that the paginated REST API will provide a link for the
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next page of results in the `Link` header, e.g.:
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Link: <https://api.example.com/search?q=abc&page=2>; rel="next"
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Absence of a link with `rel="next"` in the response headers is assumed
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to mean the final page of results has been reached.
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# Example Usage
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import Http
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import Json.Decode exposing (string)
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import Paginated exposing (Response(..))
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type alias Model =
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{ results : Maybe (Paginated.Response String) }
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type Msg
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= Search
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| Results (Result Http.Error (Paginated.Response String))
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update : Msg -> Model -> ( Model, Cmd Msg )
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update msg model =
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case msg of
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Search ->
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( model, doSearch )
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Results (Ok response) ->
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case response of
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Partial request results ->
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( { model
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| results =
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Maybe.map (\x -> Paginated.update x response)
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model.results
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}
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, Paginated.send Results request
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)
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Complete results ->
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( { model
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| results =
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Maybe.map (\x -> Paginated.update x response)
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model.results
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}
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, Cmd.none
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)
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Results (Err _) ->
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( model, Cmd.none )
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doSearch : Cmd Msg
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doSearch =
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Paginated.send Results <|
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Paginated.get "http://example.com/items" string
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