How to use ToOneRelationship() and serializeAs() on the same attribute?

[gaetanm]

You will understand just by looking at my class:

import Spine

class Menu: Resource {
    var nbrOfRecipes: Int?
    var userID: User?
    var recipes: LinkedResourceCollection?
    
    override class var resourceType: ResourceType {
        return "menus"
    }
    
    override class var fields: [Field] {
        return fieldsFromDictionary([
            "nbrOfRecipes": Attribute().serializeAs("nb-recipes"),
            "userID": Attribute().serializeAs("user-id"),
            "userID": ToOneRelationship(User.self),
            "recipes": ToManyRelationship(Recipe.self)
            ])
    }
}

As you can guess, this result in a fatal error: Dictionary literal contains duplicate keys.

How to do to apply both ToOneRelationship(User.self) and Attribute().serializeAs("user-id") on the same attribute?

[markst]

@gaetanm why do you need to apply both attributes on the same property?
why not have two properties one for the user relationship & the other for user-id?

class Menu: Resource {
    var nbrOfRecipes: Int?
    var userID: String?
    var user: User?

[markst]

Perhaps you could provide an example of your response JSON to make it clear?

[gaetanm]

I don't know enough about how Spine works internally to know that it was possible to use 2 properties for the same JSON data. Interesting!

About the JSON response, it's like this:

"data": {
    "id": "4",
    "type": "menus",
    "attributes": {
      "nb-recipes": 4,
      "created-at": "2016-11-27 19:50:07",
      "user-id": 1
    }

By using 2 properties like you showed me, I now have an assertion failure:

Resource of type menus does not contain a field named user-id

My query is:

var query = Query(resourceType: Menu.self)
query.whereAttribute("user-id", equalTo: userID!)

My class is now:

class Menu: Resource {
    var nbrOfRecipes: Int?
    var user: User?
    var userID: String?
    var recipes: LinkedResourceCollection?
    
    override class var resourceType: ResourceType {
        return "menus"
    }
    
    override class var fields: [Field] {
        return fieldsFromDictionary([
            "nbrOfRecipes": Attribute().serializeAs("nb-recipes"),
            "userID": Attribute().serializeAs("user-id"),
            "user": ToOneRelationship(User.self),
            "recipes": ToManyRelationship(Recipe.self)
            ])
    }
}

It's really a black box for me. Do I have this error because of those 2 properties?

[markst]

to resolve the error:

Resource of type menus does not contain a field named user-id
You'll need to pass the class property name into the query:

query.whereAttribute("userID", equalTo: userID!)

Spine will perform the appropriate transform/formatting from property name to field name as described in serializeAs().

[markst]

@gaetanm please see examples on http://jsonapi.org/ for how relationships responses should look. I think your JSON should look more like this:

"data": [{
    "id": "4",
    "type": "menus",
    "attributes": {
      "nb-recipes": 4,
      "created-at": "2016-11-27 19:50:07",
    },
    "relationships": {
      "user": {
        "data": { "type": "users", "id": "1" }
      },
    }
  }],
  "included": [{
    "type": "users",
    "id": "1",
    "attributes": {
      "first-name": "Dan",
      "last-name": "Gebhardt",
    },

Which includes the relationships properties & also the associated included object

Without needing the additional user-id attribute, you can access this data through the Resource relationship data: https://github.com/wvteijlingen/Spine/blob/master/Spine/Resource.swift#L104
Whether your associated User has been included or not.

[gaetanm]

Thanks, it's more clear now.

I have a last error message:

'[<DoEat.Menu 0x6100002e4b80> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key nbrOfRecipes.'

No clue about why I have that error. I already had a similar error message in the past but it was caused by the storyboard, which seems to not be the case here.

[markst]

@gaetanm nbrOfRecipes must be a NSNumber. see documentation for using primitive types