norpan/elm-json-patch - version: 1.0.1

for more information visit the package's GitHub page

Package contains the following modules:

JSON Patch

This library implements RFC 6902, JSON Patch (and RFC 6901, JSON Pointer) for Elm.

Usage

Let's say you previously have gotten a JSON document as a Value from the server or via a port. Now you get a Value that is a JSON Patch for that document.

newDocument =
    Json.Decoder.decodeValue Json.Patch.decoder patch
        |> Result.andThen (\p -> Json.Patch.apply p document)

Patching needs to be done on the Value type, due to the type system (records can't be accessed by field name in Elm).

However, if you have an encoder/decoder pair for your Elm type, you can patch the Elm type like this:

newElmData =
    Json.Decoder.decodeValue Json.Patch.decoder patch
        |> Result.andThen
            (\p ->
                dataEncoder elmData
                    |> Json.Patch.apply p
                    |> Result.andThen (Json.Decoder.decodeValue dataDecoder)
            )