iosswiftgraphqlapollojsonencoder
"Cannot convert value of type <Custom Scalar> to expected dictionary value type 'JSONEncodable?'" for Apollo iOS
I'm struggling with using "custom scalar" for my GraphQL Apollo iOS App.
I want to get "Timestamp" as "UInt64" so I followed solution written on Apollo Tutorial. Codeine to API.swift seems using Timestamp, which is custom scalar. But there's error in API.swift:
Cannot convert value of type 'Timestamp' (aka 'UInt64') to expected dictionary value type 'JSONEncodable?'
This is part of my API.swift including query:
public final class ScheduleListQuery: GraphQLQuery {
/// The raw GraphQL definition of this operation.
public let operationDefinition: String =
"""
query ScheduleList($date: Timestamp!) {
schedules(date: $date) {
__typename
schedules {
__typename
id
name
status
category {
__typename
color
}
dateTimeStart
dateTimeEnd
stickerCount
stickerNames
}
}
}
"""
public let operationName: String = "ScheduleList"
public var date: Timestamp
public init(date: Timestamp) {
self.date = date
}
public var variables: GraphQLMap? {
return ["date": date]
}
...
This is my typealias Timestamp:
import Foundation
import Apollo
public typealias Timestamp = UInt64
extension Timestamp: JSONDecodable {
public init(jsonValue value: JSONValue) throws {
guard let string = value as? String else {
throw JSONDecodingError.couldNotConvert(value: value, to: String.self)
}
guard let timeInterval = UInt64(string) else {
throw JSONDecodingError.couldNotConvert(value: value, to: Double.self)
}
self = timeInterval
}
}
Solution
To use custom scalar value as an argument you need to code Timestamp to conform to the JSONEncodable protocol too.
public var jsonValue: JSONValue {
return String(self)
}
public init(jsonValue value: JSONValue) throws {
guard let string = value as? String else {
throw JSONDecodingError.couldNotConvert(value: value, to: String.self)
}
guard let timestamp = Int64(string) else {
throw JSONDecodingError.couldNotConvert(value: value, to: Date.self)
}
self = Int64(timestamp)
}
}