eBay Sell API: Aspects object returns 'Could not serialize field' error, when creating Inventory Item

Question

I am using eBay's new REST Sell API to create an inventory item. I am having problems creating product aspects manually. I've tried creating a list of name value pairs but eBay is returning the following error:

Could not serialize field [product.aspects]

Below is the request payload sample from eBay:

{
    "availability": {
        "shipToLocationAvailability": {
            "quantity": 50
        }
    },
    "condition": "NEW",
    "product": {
        "title": "GoPro Hero4 Helmet Cam",
        "description": "New GoPro Hero4 Helmet Cam. Unopened box.",
        "aspects": {
            "Brand": [
                "GoPro"
            ],
            "Type": [
                "Helmet/Action"
            ],
            "Storage Type": [
                "Removable"
            ],
            "Recording Definition": [
                "High Definition"
            ],
            "Media Format": [
                "Flash Drive (SSD)"
            ],
            "Optical Zoom": [
                "10x"
            ]
        },
        "imageUrls": [
            "http://i.ebayimg.com/images/i/182196556219-0-1/s-l1000.jpg",
            "http://i.ebayimg.com/images/i/182196556219-0-1/s-l1001.jpg",
            "http://i.ebayimg.com/images/i/182196556219-0-1/s-l1002.jpg"
        ]
    }
}

As far as I know product aspects are not fixed and can be anything, because of this I cannot create a Class. I'm not sure how to handle this apart from manually creating the JSON and inserting it in the correct place in the request payload.

Is there a better way to do this? Maybe create a dynamic object on the fly (any examples would help)?

Answer 1

I ended up creating a list of an Aspect object, using an extension method to manually convert the list into JSON which I deserialize into an object and pass into the request payload to eBay.

Public Class Aspect
    Property Name As String
    Property Values As String()
End Class

Public Class RequestPayload
    <JsonProperty("aspects")>
    Public Property Aspects As Object
End Class

Sub Click()

    Dim Payload As New RequestPayload

    Payload.Aspects = (New List(Of Aspect) From {
                            New Aspect With {.Name = "Brand", .Values = {"GoPro"}},
                            New Aspect With {.Name = "Type", .Values = {"Helmet/Action"}}
                        }
                    ).ToAspectsObject()

End Sub

<Extension()>
Function ToAspectsObject(Source As List(Of Aspect)) As Object

    Dim Aspects As New List(Of String)

    For Each Aspect In Source
        Aspects.Add(String.Format("""{0}"": [{1}]", Aspect.Name, String.Join(", ", Aspect.Values.Select(Function(x) String.Format("""{0}""", x)))))
    Next

    Dim JsonObject = String.Format("{{{0}}}", String.Join(", ", Aspects))

    Return Json.DeserializeObject(JsonObject)

End Function