Using Django DateField with Apollo GraphQl in Android

Hello,

If you use Qraphql with Django (Graphene) and you have a model that contains DateField then when you have an android client that use Apollo to parse the graphql you will have a parse error with date field and you will not get the data that you want.

to fix this its very easy to use custom type scaler in apollo client:

first you gonna need to add these lines in your app gradle file into the end of it

apollo {
    customTypeMapping = [
            "Date" : "java.time.LocalDate"
    ]
}

Then update your apollo client class by adding these lines to it:

var dateCustomTypeAdapter = object : CustomTypeAdapter<LocalDate> {
    override fun decode(value: CustomTypeValue<*>): LocalDate {
        try {
            return LocalDate.parse(value.value.toString())
        } catch (e: ParseException) {
            throw RuntimeException(e)
        }

    }

    override fun encode(value: LocalDate): CustomTypeValue<*> {
        return CustomTypeValue.GraphQLString(Settings.System.DATE_FORMAT.format(value))
    }
}

var okhttpClient = OkHttpClient.Builder()
    .build()

var apolloClient = ApolloClient.builder()
    .serverUrl("SERVER_BASEURL")
    .okHttpClient(okhttpClient)
    .addCustomTypeAdapter(CustomType.DATE, dateCustomTypeAdapter)
    .build()

Thats it 🙂

if you have any questions im glad to answer it in the comments below 🙂