Swift Siesta edit fetched entity - json

Question

I'm building an API client using Siesta and Swift 3 on Xcode 8. I want to be able to fetch an entity using a Siesta resource, then update some of the data and do a patch to the API.
The issue is that having an entity, if I save the JSON arrays in my entity fields I can't send them back to the server, I get the following error:
▿ Siesta.RequestError
- userMessage: "Cannot send request"
- httpStatusCode: nil
- entity: nil
▿ cause: Optional(Siesta.RequestError.Cause.InvalidJSONObject())
- some: Siesta.RequestError.Cause.InvalidJSONObject
- timestamp: 502652734.40489101
My entity is:
import SwiftyJSON
import Foundation
struct Order {
let id: String?
let sessionId: String?
let userId: Int?
let status: String?
let comment: String?
let price: Float?
let products: Array<JSON>?
init(json: JSON) throws {
id = json["id"].string
sessionId = json["sessionId"].string
userId = json["userId"].int
status = json["status"].string
comment = json["comment"].string
price = json["price"].float
products = json["products"].arrayValue
}
/**
* Helper method to return data as a Dictionary to be able to modify it and do a patch
**/
public func toDictionary() -> Dictionary<String, Any> {
var dictionary: [String:Any] = [
"id": id ?? "",
"sessionId": sessionId ?? "",
"userId": userId ?? 0,
"status": status ?? "",
"comment": comment ?? ""
]
dictionary["products"] = products ?? []
return dictionary
}
}
What I'm doing is:
MyAPI.sessionOrders(sessionId: sessionId).request(.post, json: ["products": [["product": productId, "amount": 2]], "comment": "get Swifty"]).onSuccess() { response in
let createdObject : Order? = response.typedContent()
expect(createdObject?.sessionId).to(equal(sessionId))
expect(createdObject?.comment).to(equal("get Swifty"))
expect(createdObject?.products).to(haveCount(1))
expect(createdObject?.price).to(equal(product.price! * 2))
if let createdId = createdObject?.id {
var data = createdObject?.toDictionary()
data?["comment"] = "edited Swifty" // can set paid because the user is the business owner
MyAPI.order(id: createdId).request(.patch, json: data!).onSuccess() { response in
result = true
}.onFailure() { response in
dump(response) //error is here
}
}
}
Resources:
func sessionOrders( sessionId: String ) -> Resource {
return self
.resource("/sessions")
.child(sessionId)
.child("orders")
}
func order( id: String ) -> Resource {
return self
.resource("/orders")
.child(id)
}
Transformers:
self.configureTransformer("/sessions/*/orders", requestMethods: [.post, .put]) {
try Order(json: ($0.content as JSON)["data"])
}
self.configureTransformer("/orders/*") {
try Order(json: ($0.content as JSON)["data"])
}
I've managed to circle this by creating dictionary structures like:
let products: Array<Dictionary<String, Any>>?
products = json["products"].arrayValue.map({
["product": $0.dictionaryValue["product"]!.stringValue, "amount": $0.dictionaryValue["amount"]!.intValue]
})
But I live in a hell of downcasts if I need to modify anything:
var data = createdObject?.toDictionary()
data?["comment"] = "edited Swifty"
//if I want to modify the products...
var products = data?["products"] as! Array<Dictionary<String, Any>>
products[0]["amount"] = 4
data?["products"] = products
How can I send those original JSON arrays with Siesta? They're really easy to modify and read! I've browsed the siesta docs and github issues with no success...

Answer 1

Your problem is a mismatch between SwiftyJSON and Foundation’s JSONSerialization; Siesta just happens to be in the middle of it.
InvalidJSONObject is Siesta telling you that Foundation doesn’t understand the thing you gave it — which would be the value returned by your toDictionary() method. Most of the things in that dictionary look fine: strings, ints, a float. (Careful about using float for money, BTW.)
The culprit is that products array: it’s [JSON], where JSON is a SwiftyJSON type that Foundation doesn’t know what to do with. You should be in the clear if you turn the JSON values back into simple dictionaries:
dictionary["products"] = (products ?? []).map { $0.dictionaryObject }
If that doesn’t do it, or if you need to diagnose a similar error in the future, remove all the values from the offending dictionary and then add them back in one at a time to see which one is tripping up JSONSerialization.